<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-2"> <meta name="Author" content="Michal Sobkowski"> <meta name="GENERATOR" content="Mozilla/4.79 [en] (WinNT; U) [Netscape]"> <title>Papers</title> <link rel="shortcut icon" href="msob.ico"> </head> <body style="color: rgb(0, 0, 0); background-color: rgb(204, 255, 255);" alink="#ff0000" link="#0000ee" vlink="#551a8b"> <center> <hr width="100%"> <p><b><tt><u><font color="#333300"><font size="+1">List of publications and communications</font></font></u></tt></b></p> </center> <script language="JavaScript"> <!-- function SymError() { return true; } window.onerror = SymError; var SymRealWinOpen = window.open; function SymWinOpen(url, name, attributes) { return (new Object()); } window.open = SymWinOpen; //--> </script> <script language="JavaScript"> <!-- function SymError() { return true; } window.onerror = SymError; var SymRealWinOpen = window.open; function SymWinOpen(url, name, attributes) { return (new Object()); } window.open = SymWinOpen; //--> </script> <script language="JavaScript"> <!-- function SymError() { return true; } window.onerror = SymError; var SymRealWinOpen = window.open; function SymWinOpen(url, name, attributes) { return (new Object()); } window.open = SymWinOpen; //--> </script> <script language="JavaScript"> <!-- function SymError() { return true; } window.onerror = SymError; var SymRealWinOpen = window.open; function SymWinOpen(url, name, attributes) { return (new Object()); } window.open = SymWinOpen; //--> </script> <script> <!-- var Domain = "DOMENA" var Mailme = "mail" + "to:" + "msob@" + "ibch.poznan.pl" document.write("<FORM>"); document.write("<INPUT TYPE=\"submit\" VALUE=\"Reprint request\" "); document.write("onClick=\"parent.location=Mailme\"> "); document.write("</FORM>"); // --> </script><br> <hr width="100%"> <blockquote> <center><b><font size="+2">1993</font></b></center> <div style="text-align: justify;"><font size="+1">1) A. Kraszewski, M. Sobkowski &amp; J. StawiDski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1039/P19930001699">Studies on Reactions of Nucleoside&nbsp;<span style="font-style: italic;">H</span>-Phosphonates with Bifunctional Reagents. 1. Reaction with Amino Alcohols</a>"</font> <br> <font size="+1"><i>J. Chem. Soc. Perkin Trans. 1</i>, 1699-1704, 1993.</font><br> <font color="#660000"><u>Abstract:</u> The reaction of nucleoside H-phosphonates with amino alcohols in the presence of condensing agents has been studied. Depending on the coupling procedure used and the length of the polymethylene bridge in the amino alcohols, different H-phosphonate diesters, cyclic phosphoramidite derivatives or phosphite triesters can be produced. Oxidation of these species with iodine under various experimental conditions has been studied and a general procedure for synthesis of nucleoside alkyl phosphodiesters has been developed.</font> <br> </div> <p>&nbsp;&nbsp; <br> </p> <center> <p><b><font size="+2">1994</font></b></p> </center> <p style="text-align: justify;"><font size="+1">2) G. Ott, L. Arnold, J. Smrt, M. Sobkowski, S. Limmer, H.P. Hofmann &amp; M. Sprinzl</font><br> <font size="+1">"<a href="http://dx.doi.org/10.1080/15257779408011880">The chemical synthesis of biochemically active oligoribonucleotides using dimethylaminomethlene protected purine&nbsp;<span style="font-style: italic;">H</span>-phosphonates</a>"</font> <br> <font size="+1"><i>Nucleosides Nucleotides</i>, <b>13 </b>(5), 1069-1085, 1994.</font> <br> <font color="#660000"><u>Abstract: </u>Dimethylaminomethylene was applied as the protecting group for the exocyclic amino groups of adenosine and guanosine in the automated chemical synthesis of oligoribonucleotides on a polymer bound support. The dimethylaminomethylene protecting group can be removed at room temperature under conditions where the concomitant loss of the 2'-protection group can be excluded. The transformation of 2'-O-(t-butyldimethylsilyl)-5'-O-(4,4'-dimethoxytrityl) protected nucleosides to 3'-H-phosphonates yields synthons, well suited for the automated chemical synthesis of oligoribonucleotides. Using these H- phosphonate monomers, a coupling time of two minutes is sufficient to obtain average coupling yields of more than 98 %. Synthesized RNA is recognized as a substrate in an enzymatic reaction, forms the expected secondary structures and is suitable for NMR structural investigations.</font> <br> </p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font size="+1">3) J. Jankowska, M. Sobkowski, J. StawiDski &amp; A. Kraszewski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1016/S0040-4039%2800%2976906-1">Studies on aryl&nbsp;<span style="font-style: italic;">H</span>-phosphonates. 1. An efficient method for the preparation of deoxyribo-and ribonucleoside 3'-<span style="font-style: italic;">H</span>-phosphonate monoesters by transesterification of diphenyl&nbsp;<span style="font-style: italic;">H</span>-phosphonate</a>"</font> <br> <font size="+1"><i>Tetrahedron Lett.</i>, <b>35 </b>(20), 3355-3358, 1994.</font> <br> <font color="#660000"><u>Abstract:</u> A convenient method for the preparation of deoxyribonucleoside and ribonucleoside 3'-H-phosphonate monoesters via transesterification of diphenyl H- phosphonate with suitable protected nucleosides in pyridine is described.</font> <br> </p> <div style="text-align: justify;"> </div> <div style="text-align: justify;"><font size="+1">4) M. Sobkowski, J. StawiDski, A. Sobkowska &amp; A. Kraszewski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1039/P19940001803">Studies on reactions of nucleoside&nbsp;<span style="font-style: italic;">H</span>-phosphonates with bifunctional reagents. 2. Stability of nucleoside&nbsp;<span style="font-style: italic;">H</span>-phosphonate diesters in the presence of amino alcohols</a>"</font> <br> <font size="+1"><i>J. Chem. Soc. Perkin Trans. 1</i>, 1803-1808, 1994.</font> <br> <font color="#660000"><u>Abstract:</u> H-Phosphonate diesters undergo transesterification with amino alcohols to afford as primary products the mixed and the symmetrical H-phosphonate esters. Alcohols react similarly but only in the presence of an external base or in a basic solvent. The rate and the course of transesterification strongly depend on the reaction conditions, the reactivity of the H-phosphonate diester used and the nature of the amino alcohol.</font> <br> </div> <p>&nbsp;&nbsp; <br> </p> <center> <p><b><font size="+2">1995</font></b></p> </center> <p style="text-align: justify;"><font size="+1">5) M. Sobkowski, J. StawiDski &amp; A. Kraszewski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1016/0040-4039%2895%2900238-8">Studies on reactions of nucleoside&nbsp;<span style="font-style: italic;">H</span>-phosphonate diesters with bifunctional reagents. 4. Chemoselectivity during oxidative coupling of nucleoside&nbsp;<span style="font-style: italic;">H</span>-phosphonate diesters with amino alcohols controlled by protonation of the amino function</a>"</font> <br> <font size="+1"><i>Tetrahedron Lett.</i>, <b>36 </b>(13), 2295-2298, 1995.</font> <br> <font size="+1">Alternate link: <a href="http://vls.icm.edu.pl/cgi-bin/sciserv.pl?collection=elsevier&amp;journal=00404039&amp;issue=v36i0013&amp;article=2295_soronhbpotaf&amp;form=pdf&amp;file=file.pdf">ICM&nbsp;&nbsp; Biblioteka Wirtualna Nauki</a></font> <br> <font color="#660000"><u>Abstract: </u>A Kraszewski, Polish Acad Sci, Inst Bioorgan Chem, Noskowskiego 12-14, PL-61704 Poznan, Poland The course of oxidative coupling of H-phosphonate diesters with amino alcohols, promoted by iodine, can be controlled by protonation of the amine function of amino alcohols. Based on this phenomenon, a rapid and efficient method for synthesis of aminoalkyl phosphotriesters or hydroxyalkyl phosphoramidates was developed.</font> <br> </p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font size="+1">6) A. Kers, I. Kers, J. StawiDski, M. Sobkowski &amp; A. Kraszewski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1055/s-1995-3919">Studies on aryl H-phosphonates. 2. A general method for the preparation of alkyl&nbsp;<span style="font-style: italic;">H</span>-phosphonate monoesters</a>"</font> <br> <font size="+1"><i>Synthesis</i>, <b>4</b>, 4427-4430, 1995.</font> <br> <font color="#660000"><u>Abstract:</u> A simple and efficient synthetic method for the preparation of alkyl H-phosphonate monoesters has been developed. The method consists of transesterification of commercially available diphenyl H-phosphonate with an appropriate alcohol under mild conditions, followed by ammonolysis of the in situ formed dialkyl and alkyl phenyl H-phosphonates.</font>&nbsp;&nbsp;</p> <div style="text-align: justify;"> </div> <div style="text-align: justify;"><font size="+1">7) A. Sobkowska, M. Sobkowski, J. StawiDski &amp; A. Kraszewski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1080/15257779508012453">Studies on aryl&nbsp;<span style="font-style: italic;">H</span>-phosphonates. Synthesis of nucleoside&nbsp;<span style="font-style: italic;">N</span>-alkylphosphonamidates</a>"</font> <br> <font size="+1"><i>Nucleosides Nucleotides</i>, <b>14 </b>(3-5), 703-706, 1995.</font> <br> <font color="#660000"><u>Abstract:</u> The aminolysis of aryl nucleoside H-phosphonate diesters with various amines was studied. The new simple and efficient method of synthesis of nucleoside phosphonamidates is described.</font><br> <font color="#660000"> </font><br> <font color="#660000"> </font><font size="+1">8) M. Sobkowski, J. StawiDski, A. Sobkowska &amp; A. Kraszewski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1080/15257779508012484">Studies on reactions of nucleoside&nbsp;<span style="font-style: italic;">H</span>-phosphonates with bifunctional reagents. 3. Further studies on transesterification of nucleoside&nbsp;<span style="font-style: italic;">H</span>-phosphonate diesters with amino alcohols</a>"</font> <br> <font size="+1"><i>Nucleosides Nucleotides</i>, <b>14 </b>(3-5), 839-842, 1995..</font> <br> <font color="#660000"><u>Abstract:</u> Reactions of 5'-O-(4,4'-dimethoxytrityl)thymidin-3'-yl 2-cyanoethyl phosphonate with alcohols, amines and amino alcohols in pyridine are described. Transesterification was found to be faster than beta-elimination of 2- cyanoethyl group.</font> <br> </div> <p>&nbsp;&nbsp; <br> </p> <center> <p><b><font size="+2">1996</font></b></p> </center> <p style="text-align: justify;"><font size="+1">9) J. StawiDski, A. Kraszewski &amp; M. Sobkowski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1080/10426509608545140">Exploring Reactions of Nucleoside&nbsp;<span style="font-style: italic;">H</span>-phosphonates with Bifunctional Reagents</a>"</font> <br> <font size="+1"><i>Phos. Sulf. Sil.</i>, <b>109-110</b>, 261-264, 1996.</font> <br> <font color="#660000"><u>Abstract:</u> Studies on reactions of nucleoside H-phosphonates with various amino alcohols showed that: (i) condensations of H-phosphonate monoesters with amino alcohols proceed with a complete chemoselectivity producing H-phosphonate diesters exclusively; (ii) H-phosphonate diesters undergo transesterification with amino alcohols and afford various products depending on the reaction conditions; (iii) the course of the oxidative coupling of nucleoside H-phosphonate diesters with amino alcohols can be controlled by protonation of the amino function, and thus the reaction can be steered to afford aminoalkyl phosphotriesters or hydroxyalkyl phosphoramidates.</font></p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"> </p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"> <font size="+1">10) M. Sobkowski, J. StawiDski &amp; A. Kraszewski</font> <br> <font size="+1">"Aryl&nbsp;<span style="font-style: italic;">H</span>-phosphonates. Part 5. A Simple Method for the Synthesis of Aminoalkyl&nbsp;<span style="font-style: italic;">H</span>-phosphonate Monoesters <i>via</i> Transesterification of Difenyl&nbsp;<span style="font-style: italic;">H</span>-phosphonate with Amino Alcohols"</font> <br> <font size="+1"><i>Collection Czechoslov. Chem. Commun.</i>, <b>61</b>, S238-S241, 1996.</font> <br> <font color="#660000"><u>Abstract:</u> A new method for the synthesis of N-dimethoxytritylated aminoalkyl H-phosphonate monoesters is described. It consists of transesterification of diphenyl H-phosphonate with an amino alcohol, hydrolysis of the produced di(aminoalkyl) H-phosphonate diester to the corresponding monoester, followed by its tritylation, and silica gel purification of the final product..</font> </p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font size="+1">11) A. Kers, I. Kers, J. StawiDski, M. Sobkowski &amp; A. Kraszewski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1016/0040-4020%2896%2900525-X">Studies on aryl&nbsp;<span style="font-style: italic;">H</span>-phosphonates. 3. Mechanistic investigations related to the disproportionation of diphenyl&nbsp;<span style="font-style: italic;">H</span>-phosphonate under anhydrous basic conditions</a>"</font> <br> <font size="+1"><i>Tetrahedron</i>, <b>52 </b>(29), 9931-9944, 1996.</font> <br> <font size="+1">Alternate link: <a href="http://vls.icm.edu.pl/cgi-bin/sciserv.pl?collection=elsevier&amp;journal=00404020&amp;issue=v52i0029&amp;article=9931_soah3mdhuabc&amp;form=pdf&amp;file=file.pdf">ICM&nbsp;&nbsp; Biblioteka Wirtualna Nauki</a></font> <br> <font color="#660000"><u>Abstract:</u> Diphenyl H-phosphonate undergoes under anhydrous reaction conditions a base-promoted disproportionation to triphenyl phosphite and phenyl H-phosphonate. On the basis of P-31 NMR data the most likely mechanism for this transformation was proposed. In order to substantiate these findings and to get a deeper insight into the chemistry of aryl H-phosphonate esters, we carried out also some studies on activation of phenyl and diphenyl H-phosphonates with various condensing agents. We found that aryl vs alkyl esters of phosphonic acid often follow different reaction pathways during the activation, and this can most likely be traced back to higher electrophilicity of the phosphorus centre and to higher reactivity of the P-H bonds in aryl H-phosphonate derivatives.</font> </p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font size="+1">12) J. Cie[lak, M. Sobkowski, A. Kraszewski &amp; J. StawiDski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1016/0040-4039%2896%2900846-5">Aryl&nbsp;<span style="font-style: italic;">H</span>-phosphonates. 4. A new method for internucleotide bond formation based on transesterification of aryl nucleoside&nbsp;<span style="font-style: italic;">H</span>-phosphonate diesters</a>"</font> <br> <font size="+1"><i>Tetrahedron Lett.</i>, <b>37 </b>(26), 4561-4564, 1996.</font> <br> <font size="+1">Alternate link: <a href="http://vls.icm.edu.pl/cgi-bin/sciserv.pl?collection=elsevier&amp;journal=00404039&amp;issue=v37i0026&amp;article=4561_ahpiantoanhd&amp;form=pdf&amp;file=file.pdf">ICM&nbsp;&nbsp; Biblioteka Wirtualna Nauki</a></font> <br> <font color="#660000"><u>Abstract:</u> Under mild reaction conditions nucleoside aryl H- phosphonate diesters undergo fast and efficient transesterification with suitably protected nucleosides, affording dinucleoside (3'-5') H-phosphonate diesters.</font></p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font size="+1">13) J. Cie[lak, J. Jankowska, A. Kers, I. Kers, A. Sobkowska, M. Sobkowski, J. StawiDski &amp; A. Kraszewski</font> <br> <font size="+1">"Synthetic Applications of Aryl&nbsp;<span style="font-style: italic;">H</span>-phosphonates in Nucleotide Chemistry"</font> <br> <font size="+1"><i>Collection Czechoslov. Chem. Commun.</i>, <b>61</b>, S242-S245, 1996.</font> <br> <font color="#660000"><u>Abstract:</u> Aryl nucleoside H-phosphonate diesters were found to be versatile synthetic intermediates for the preparation of various functionalized alkyl nucleoside H-phosphonates, dinucleoside H-phosphonates, and nucleoside H-phosphonamidates.</font> </p> <div style="text-align: justify;"> </div> <div style="text-align: justify;"><font size="+1">14) A. Kers, I. Kers, A. Kraszewski, M. Sobkowski, T. Szab, M. Thelin, R. Zain &amp; J. StawiDski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1080/07328319608002390">Nucleoside Phosphonates. Development of Synthetic Methods and Reagents</a>"</font> <br> <font size="+1"><i>Nucleosides Nucleotides</i>, <b>15 </b>(1-3), 361-378, 1996.</font> <br> </div> <p>&nbsp; &nbsp; <br> </p> <center> <p><b><font size="+2">1997</font></b></p> </center> <div style="text-align: justify;"><font size="+1">15) A. Sobkowska, M. Sobkowski, J. Cie[lak, A. Kraszewski,&nbsp; I. Kers &amp; J. StawiDski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1021/jo962224z">Aryl&nbsp;<span style="font-style: italic;">H</span>-Phosphonates. 6. Synthetic Studies on the Preparation of Nucleoside&nbsp;<span style="font-style: italic;">N</span>-Alkyl-<span style="font-style: italic;">H</span>-phosphonamidates</a>"</font> <br> <font size="+1"><i>J. Org. Chem.</i>, <b>62 </b>(14), 4791-4794, 1997.</font> <br> <font color="#660000"><u>Abstract:</u> Various approaches to the synthesis of nucleoside H-phosphonamidates have been investigated. Direct couplings of nucleoside H-phosphonates with amines have been hampered by extensive reactions of the condensing agents with amines. Preactivation of nucleoside H-phosphonates with pivaloyl chloride or chlorophosphates, followed by the addition of amines, notably diminished these side reactions. The most efficient and versatile route to nucleoside N-alkyl H-phosphonates was found to be aminolysis of the in situ-produced aryl nucleoside H-phosphonates with appropriate amines.</font> <br> </div> <p>&nbsp;&nbsp; <br> </p> <center> <p><b><font size="+2">1998</font></b></p> </center> <p style="text-align: justify;"><font size="+1">16) M. Sobkowski, A. Kraszewski &amp; J. StawiDski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1080/07328319808005174">The Reactions of&nbsp;<span style="font-style: italic;">H</span>-Phosphonates with Bifunctional Reagents. Part V. Functionalization of Support-Bound Oligonucleotides and Synthesis of Non-Radioactive Hybridization Probes</a>"</font> <br> <font size="+1"><i>Nucleosides Nucleotides</i>, <b>17 </b>(1-3), 253-267, 1998.</font> <br> <font color="#660000"><u>Abstract:</u> Three methods for the functionalization of oligonucleotides with aminoalkyl moieties have been developed and their efficiencies were evaluated in the preparation of non-radioactive hybridization probes.</font> </p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font size="+1">17) J. Jankowska, A. Sobkowska, J. Cie[lak, M. Sobkowski, A. Kraszewski, J. StawiDski &amp; D. Shugar</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1021/jo980491u">Nucleoside&nbsp;<span style="font-style: italic;">H</span>-phosphonates. 18. Synthesis of unprotected nucleoside 5'-<span style="font-style: italic;">H</span>-phosphonates and nucleoside 5'-<span style="font-style: italic;">H</span>-phosphonothioates and their conversion into the 5'-phosphorothioate and 5'-phosphorodithioate monoesters</a>"</font> <br> <font size="+1"><i>J. Org. Chem.</i>, <b>63 </b>(23), 8150-8156, 1998.</font> <br> <font color="#660000"><u>Abstract:</u> A simple and efficient protocol for the preparation of unprotected nucleoside 5'-H-phosphonates and nucleoside 5'- H-phosphonothioates via a one-step deprotection of suitable precursors with methylamine has been developed. The synthetic utility of the unprotected nucleotide derivatives was demonstrated by converting them under mild conditions to the corresponding nucleoside 5'- phosphorothioate and nucleoside 5'-phosphorodithioate monoesters. Factors affecting oxidation of H-phosphonate, H-phosphonothioate, and phosphite derivatives with elemental sulfur are also discussed.</font> <br> &nbsp; </p> <div style="text-align: justify;"> </div> <div style="text-align: justify;"><img src="Na%20pograniczu%20chemii%20i%20biologii.jpg" align="left" height="105" width="71"><font size="+1">18) M. Sobkowski &amp; A. Kraszewski</font> <br> <font size="+1">"Oligonukleotydowe sondy molekularne o detekcji nieradioizotopowej"</font> <br> <font size="+1">in "<i>Na pograniczu chemii i biologii</i>" vol. 1, pp. 17-80, Wydawnictwo Naukowe UAM, PoznaD 1998</font> <br> </div> <p>&nbsp; <br> &nbsp; <br> </p> <center> <p><b><font size="+2">1999</font></b></p> </center> <p style="text-align: justify;"><font size="+1">19) H. Seliger, M. Hinz, P. Jaisankar, M. Sobkowski, R. Ditz &amp; F. Eisenbeiss</font> <br> <font size="+1">"A polymer support with unusually high loading capacity for large-scale oligonucleotide synthesis"</font> <br> <font size="+1">Poster presented at: IBC's 6th International Conference on Oligo-Therapeutics / IBC's 3rd International Conference on Oligo-Technologies, May 5-6, 1999, La Jolla, CA, USA</font> <br> <font color="#660000"><u>Abstract:</u> The production of multikilogram quantities of synthetic oligonucleotides for therapeutic purposes calls for the development of new methodology, not just the scale-up of existing techniques. The use of supports with very high loading is particularly attractive, since the required amount of solid phase support per unit production of oligonucleotide is significantly reduced, as is the cost of disposal or regeneration. This likewise reduces the expenditure for apparatus and consumables. based on earlier experiments with macroporous PVA Merckogel resins, we have developed a new supportsystem with loading capacity ranging between 100 and 1000 micromol nucleoside/g. Applying standard phosphoramidite chemistry, oligonucleotides with typically up to 20 bases, but also longer sequences, could be prepared with yields of chain elongation averaging up to 99%. Even assuming only 97% average yield of chain extension, this constitutes a ca. 8-fold higher oligonucleotide output per unit support weight with respect to conventional 50 micromol/g supports, and ca. 3-fold with respect to 200 micromol/g "high-load" supports. Calculation of the composition of the support system after synthesis shows, that with loading around 700 to 800 micromol/g the material obtained after the preparation of a 20-mer consists of ca. 80% oligonucleotide and only 20% of polymeric support material. Applications of such supports, as well as studies on different reaction conditions and activating agents will be reported..</font> </p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font size="+1">20) J. Cie[lak, J. Jankowska, M. Sobkowski, A. Kers, I. Kers, J. StawiDski &amp; A. Kraszewski</font> <br> <font size="+1">"The Reactions of Aryl Nucleoside&nbsp;<span style="font-style: italic;">H</span>-phosphonates with O-, N-, and S-nucleophiles"</font> <br> <font color="#660000"><u>Abstract:</u> Aryl nucleoside H-phosphonates, derivatives of controlled reactivity, have been developed as useful synthetic intermediates for the preparation of variety of nucleotide analogues containing P-O, P-N and P-S bonds.</font> <br> <font size="+1"><i>Collection Symp. Series </i><b>2</b>, 63-68, 1999</font> <br> <a href="http://users.man.poznan.pl/msob/tresc99/The%20reactions%20of%20aryl%20nucleoside%20H-phosphonates%20with%20O-%20N-%20and%20S-nucleophiles.pdf">Full text PDF</a> </p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font size="+1">21) H. Seliger, M. Hinz, M. Sobkowski, R. Ditz &amp; F. Eisenbeiss</font> <br> <font size="+1">"High load support material for oligonucleotide synthesis"</font> <br> <font size="+1">Poster presented at: "Biotechnica", October 5-7, 1999, Hanover, Germany</font> <br> <font color="#660000"><u>Abstract</u>: The synthesis of large amounts of oligonucleotides is still rather expensive, thus hampering the development and use of therapeutic oligo-nucleotides. The support material accounts for a large percentage of these costs. An increase in loading of the support material will still maintaining high coupling efficiency would not only diminish direct costs of the support material but also indirect costs by allowing a smaller design of the synthesizer. Together with Merck KGaA, a new support material, based on Merckogel OR 1000000 has been developed, meeting the requirements of large scale oligonucleotide synthesis nearly ideally.</font> </p> <div style="text-align: justify;"> </div> <div style="text-align: justify;"><font size="+1">22) H. Seliger, M. Sobkowski, M. Hinz, P. Jaisankar, R. Ditz, F. Eisenbeiss, H. Knoller, R. Zimmermann, A. Rck, K. Heckelsmiller, R. Steiner &amp; R. Masantschek</font> <br> <font size="+1">"Some Recent Contributions to Antisense Research. International Symposium on Drug Regulation of Gene Expression"</font> <br> <font size="+1">Communication presented at "International Symposium on Drug Regulation of Gene Expression" Bressanone, Italy, 1999.</font> <br> </div> <p>&nbsp;&nbsp; <br> </p> <center> <p><b><font size="+2">2000</font></b></p> </center> <p style="text-align: justify;"><font size="+1">23) H. Seliger, M. Hinz, R.K. Pandey, J. Simanowski, M. Sobkowski, S. Hahner, F. Hillenkamp, R. Ditz &amp; F. Eisenbeiss</font> <br> <font size="+1">"Bead Technology for Oligonucleotide Libraries and Large-Scale Synthesis"</font> <br> <font size="+1">Poster presented at: "Millennium Conference on Nucleic Acid Therapeutics", 8-11 January, 2000, Clearwater Beach, Florida, USA</font> <br> <font color="#660000"><u>Abstract</u>:&nbsp; Particle Systems with unusually high loading capacity are the basis (1.) for combinatorial libraries of synthetic oligonucleotides used in the discovery of diagnostic and therapeutic lead structures and (2.) for the large-scale preparation of therapeutic oligonucleotides. After having scanned a number of commercial beads for these purposes, our work currently concentrates on Tentagel<sup>(R)</sup> (Rapp Polymers, Tbingen) and Merckogel<sup>(R)</sup> (Merck KGaA, Darmstadt). Both polymers are of spherical shape, can be obtained with quite uniform size, are mechanically stable and are produced/functionalized with hydroxy or amino groups.</font> <br> <font color="#660000">Ad (1.) Beads of size around 30 microm diameter with nucleotide loading around 200 micromol/g were selected for the preparation of libraries. Oligonucleotide synthesis was done according to the "split/couple/combine" procedure<sup>1</sup> with yields of chain extension around 98%. Specificity tests of e.g. octanucleotide libraries were done routinely by hybridization to fluorescently labeled oligonucleotides, selection of fluorescent particles, followed by dehybridization and detection of the sequence off single beads by MALDI-TOF mass spectroscopy. This procedure has been extended to screening high-affinity oligonucleotide-protein interactions. As an example, the binding of thrombin to an octanucleotide library was analyzed and will be dis-cussed in relation to previous lead structures generated through solution aptamer techniques<sup>2</sup>.</font> <br> <font color="#660000">Ad (2.) Beads, that (a) are characterized by having unusually high loading capacity and (b) nevertheless give near-quantitative yields of chain extension, are particularly advantageous for the scale-up of oligonucleotide synthesis. Our efforts are concentrated on Merckogel<sup>(R)</sup>, a macroporous polyvinylacetate resin, functionalized via partial hydrolysis, which meets these requirements better than any other currently available particle system. Up to capacities of 500-600 micromol nucleotide/g the chainextension on such resins proceeds with 98-99% average. The productivity of such a high-load system is demonstrated by the fact, that after preparation of a 20mer the immobilized oligodeoxynucleotide comprises ca. 60% of the total weight of the carrier. The loading capacities can even be increased to 1000 micromol/g and beyond, however, resulting in decreased synthesis efficiency. Since the Merckogel<sup>(R)</sup> shows similar swelling in all solvents used during the phosphoramidite cycle, these characteristics may contribute to a significant reduction of the volume of reaction vessels as well as the cost of chemicals and equipment during the large-scale production of therapeutic oligonucleotides.</font> </p> <div style="text-align: justify;"> </div> <ol style="text-align: justify;"> <li> <font color="#660000">A. Furka, F. Sebestyen, M. Agesdom, G. Dibo, Abstracts, l4th Internat. Congress Biochem. <u>1988</u>, 47, Int. J. Peptide Protein Res. <u>37</u>, 487-491 (1991); K.S. Lam, S.E. Salmon, E.M. Hersh, W.J. Hruby, W.M. Kasmierski, R.J. Knapp, Nature <u>354</u>, 82-84 (1991).</font></li> <li> <font color="#660000">L.C. Bock, L. Griffin, J.A. Latham, E.H. Vermaas, J.J. Toole, Nature <u>335</u>, 564-566 (1992); K.Y. Wang, S. McCurdy, R.G. Shea, 5. Swaminathan, P.H. Bolton, Biochemistry <u>32</u>, 1899- 1904 (1993).</font></li> </ol> <div style="text-align: justify;"> <font size="+1">24) M. Sobkowski, M. Hinz, R. Ditz, F. Eisenbeiss, M. Rimmler &amp; H. Seliger</font> <br> <font size="+1">"A high-load polymer support for the production of oligonucleotides of therapeutic interest"</font> <br> <font size="+1">Proceedings of XIV International Round Table "Nucleosides, Nucleotides and Their Biological Applications", San Francisco 2000, p. 128 (Abstract 205)</font> <br> <font color="#660000"><u>Abstract</u>:&nbsp; The synthesis of large quantities of synthetic oligonucleotides for therapeutic applications requires the development of a technical-scale methodology. Supports with very high loading are essential, if the expenditure for the preparation, regeneration or disposal of the support material, as well as the cost of apparatus and consumables are to be minimized. We have developed high-load support materials based on macroporous polyvinylacetate resins (MerckogelR), which almost ideally meet the requirements for large-scale oligonucleotide synthesis. The MerckogelR supports are featured by the following characteristics:</font>-<font color="#660000">Procedures have been developed for controlled partial hydrolysis without disruption of the macroporous structure.</font>-<font color="#660000">The nucleoside capacity can be regulated by variation of the loading conditions, yielding reproducibly up to 900 micromol/g.</font>-<font color="#660000">The support material is compatible with standard oligonucleotide chain extension chemistry and workup procedures.</font>-<font color="#660000">The supports have nearly equal swelling properties in various apolar solvents used during the oligonucleotide elongation cycle.</font>-<font color="#660000">Standardized protocols have been developed to achieve 98-99% average cycle yields in the preparation of 15-30 base oligonucleotides with carriers loaded up to 350 micromol/g; similar yields have been obtained in experiments with support capacities of 500 micromol/g and more.</font> </div> <div style="text-align: justify;"><font size="+1">25) M. Sobkowski, M. Wenska, A. Kraszewski &amp; J. StawiDski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1080/15257770008045441">Studies on reactions of nucleoside&nbsp;<span style="font-style: italic;">H</span>-phosphonates with bifunctional reagents. Part VI. Reaction with diols</a>"</font> <br> <font size="+1"><i>Nucleosides Nucleotides Nucleic Acids </i><font color="#330000"><b>19</b> (10-12), 1487-1503, 2000.</font></font> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: Reactions of nucleoside H-phosphonates with various diols using different types of condensing agents have been studied. Depending on the coupling procedure and the length of a polymethylene chain of the diol, acyclic H-phosphonate diesters or cyclic phosphite triesters were formed. The course of oxidation with iodine to produce cyclic nucleoside alkyl phosphotriesters or hydroxyalkyl nucleoside phosphodiesters can be controlled by the amount of water present in the reaction medium.</font></font> <br> </div> <p>&nbsp;&nbsp; <br> </p> <center> <p><b><font size="+2">2001</font></b></p> </center> <p style="text-align: justify;"><font color="#000000"><font size="+1">26)&nbsp; H. Seliger, M. Sobkowski &amp; M. Hinz</font></font> <br> <font color="#000000"><font size="+1">"Large Scale-Synthese modifizierter Oligonukleotide"</font></font> <br> <font color="#000000"><font size="+1">("Intermediate for oligonucleotide synthesis comprises partially hydrolysed cross-linked vinyl acetate copolymer loaded with nucleotide derivative")</font></font> <br> <font color="#000000"><font size="+1"><a href="http://v3.espacenet.com/publicationDetails/biblio?DB=EPODOC&amp;adjacent=true&amp;locale=en_PL&amp;FT=D&amp;date=20010510&amp;CC=DE&amp;NR=10051726A1&amp;KC=A1">Deutsches Patent DE 10051726 A</a>, 2001.</font></font> <br> <font color="#000000"><font size="+1"><a href="http://users.man.poznan.pl/msob/title.pdf">Title page.pdf</a></font></font> </p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font size="+1">27) J. Cie[lak, M. Sobkowski, J. Jankowska, M. Wenska, M. Szymczak, B. ImioBczyk, I. Zagrowska, D. Shugar, J. StawiDski &amp; A. Kraszewski</font> <br> <font size="+1">"<a href="http://www.actabp.pl/pdf/2_2001/429-442s.pdf">Nucleoside phosphate analogues of biological interest, and their synthesis via aryl nucleoside&nbsp;<span style="font-style: italic;">H</span>-phosphonates as intermediates</a>"</font> <br> <font size="+1"><i>Acta Biochim.Pol.</i> <b>48</b> (2), 429-442, 2001.</font> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: This review presents a brief account of the chemistry and mechanistic aspects of aryl H-phosphonates, and selected applications of this class of compounds as intermediates in the synthesis of a wide range of biologically important analogues of nucleoside phosphates, and oligonucleotides, in which the phosphate moieties are replaced by other structurally related groups. The aryl nucleoside H-phosphonates, compounds of controlled reactivity, have proven to be more versatile and superior to various mixed anhydrides as synthetic intermediates, particularly for preparation of nucleotide analogues bearing P-N or P-S bonds in various configurational arrangements at the phosphate moiety.</font></font> </p> <div style="text-align: justify;"> </div> <div style="text-align: justify;"><font size="+1">28) M. Wenska, J. Jankowska, M. Sobkowski, J. StawiDski &amp; A. Kraszewski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1016/S0040-4039%2801%2901695-1">A new method for the synthesis of nucleoside 2',3'-<span style="font-style: italic;">O,O</span>-cyclic phosphorodithioates via aryl cyclic phosphites as intermediates</a>"</font> <br> <font size="+1"><i>Tetrahedron Letters</i> <b>42</b> (45), 8055-8058, 2001.</font> <br> <font size="+1">Alternate link: <a href="http://vls.icm.edu.pl/cgi-bin/sciserv.pl?collection=elsevier&amp;journal=00404039&amp;issue=v42i0045&amp;article=8055_anmftsvacpai&amp;form=pdf&amp;file=file.pdf">ICM&nbsp;&nbsp; Biblioteka Wirtualna Nauki</a></font> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: The reaction of 5'-O-protected ribonucleosides with tri(4-nitrophenyl) phosphite in the presence of pyridine furnished rapid formation of the corresponding 4-nitrophenyl 2',3'-O,O-cyclic phosphites which upon sulfhydrolysis, followed by sulfurization of the resultant cyclic H-phosphonothioate and removal of the 5'-O-protecting groups, afforded nucleoside 2',3'-O,O-cyclic phosphorodithioates in high yields.</font></font> <br> </div> <p>&nbsp;&nbsp; <br> </p> <center> <p><b><font size="+2">2002</font></b></p> </center> <p style="text-align: justify;"><font color="#000000"><font size="+1">29) J. Cie[lak, J. Jankowska, M. Sobkowski, M. Wenska, J. StawiDski &amp; A. Kraszewski</font></font> <br> <font color="#000000"><font size="+1">"<a href="http://dx.doi.org/10.1039/b109373h">Aryl&nbsp;<span style="font-style: italic;">H</span>-phosphonates. Part 13. A new, general entry to aryl nucleoside phosphate and aryl nucleoside phosphorothioate diesters</a>"</font></font> <br> <font color="#000000"><font size="+1"><i>J.Chem.Soc.Perkin Trans. 1</i>, 31-37, 2002.</font></font> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: The reaction of nucleoside H-phosphonate monoesters with phenols in the presence of a condensing agent, followed by oxidation of the in-situ-generated aryl nucleoside H-phosphonate diesters with iodine/water or with elemental sulfur, provides a new, one-pot, efficient entry to nucleoside phosphate or nucleoside phosphorothioate diesters bearing diverse aryl moieties.</font></font> </p> <div style="text-align: justify;"> </div> <div style="text-align: justify;"><font size="+1">30) M. Sobkowski, J. Cie[lak, J. Jankowska, J. StawiDski &amp; A. Kraszewski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1135/css200205283">Dinucleoside aryl phosphorothioates as building blocks for large scale synthesis of chimeric oligonucleotide analogues</a>"</font> <br> <font size="+1"><font color="#000000">In: <i>Collection Symposium Series</i> (</font>Z. Tocik and <font color="#000000">M. Hocek, Eds.), 5, 283-289, 2002. ISBN 80-86241-16-5</font></font> <br> </div> <p>&nbsp; &nbsp; <br> </p> <center> <p><b><font size="+2">2003</font></b></p> </center> <p style="text-align: justify;"><font size="+1">31) M. Bollmark, T. Johansson, M. Kullberg, J. Nilsson, J. StawiDski, J. Cie[lak, J. Jankowska, M. Sobkowski, M. Szymczak, M. Wenska &amp; A. Kraszewski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1081/NCN-120021966">Developing synthetic methods for bioactive phosphorus compounds using&nbsp;<span style="font-style: italic;">H</span>-phosphonate chemistry: A progress report</a>"</font> <br> <font size="+1"><i>Nucleosides Nucleotides Nucleic Acids</i> <b>22</b> (5-8), 617-621, 2003.</font> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: In this paper a short account of our recent research concerning the development, of new synthetic methods and reagents for the preparation of nucleotides and their analogues, is given.</font></font> </p> <div style="text-align: justify;"> </div> <div style="text-align: justify;"><font color="#000000"><font size="+1">32) A. M. Awad, M. Sobkowski, M. Hinz &amp; H. Seliger.</font></font> <br> <font color="#000000"><font size="+1">"Novel Antisense Oligonucleotides With Enhanced Endonuclease Stability"</font></font> <br> <font size="+1">Poster presented at IBC's 4th Annual Conference EuroTIDES, November 11-12 2003, Berlin, Germany</font> <br> </div> <p>&nbsp;&nbsp; <br> </p> <center> <p><b><font size="+2">2004</font></b></p> </center> <p style="text-align: justify;"><font size="+1">33) <font color="#000000">A. M. Awad, M. Sobkowski &amp; H. Seliger.</font></font> <br> <font color="#000000"><font size="+1">"<a href="http://dx.doi.org/10.1081/NCN-120039357">Enzymatic and Hybridization Properties of Oligonucleotide Analogs Containing Novel Phosphoramidate Internucleotide Linkages</a>"</font></font> <br> <font size="+1"><i>Nucleosides Nucleotides Nucleic Acids</i> <b>23</b> (5), 777-787, 2004.</font> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: In line with the paradigm, that antisense oligonucleotides should contain minimal structural modifications, in order to minimize the risk of toxicity and antigenicity, we describe here the preparation and the properties of oligonucleotides modified to contain, in addition to phosphodiester bonds, a small number of phosphoramidate internucleotide linkages substituted with aminoethoxyethyl groups in order to convey protection against exo- and endonucleases. Prolonged stability was, in fact, found in model experiments with respective enzymes, as well as in studies done in human blood serum. Regardless of number and position of phosphoramidate linkages, the modified oligonucleotides showed only a slight decrease of Tm in hybridization studies with complementary oligonucleotides.</font></font> <br> &nbsp; </p> <div style="text-align: justify;"> </div> <div style="text-align: justify;"><img src="mnbk2004.gif" align="left" height="80" width="60"><font size="+1">34) Z. Wang, I. Cedillo, D. L. Cole, Y. S. Sanghvi, M. Hinz, W. PrukaBa, M. Sobkowski, H. Seliger, M. Rimmler, R. Ditz &amp; J. Hoffmeyer.</font> <br> <font size="+1">"OligoPrep: A New PVA Support for Oligonucleotide Synthesis at Large Scale"</font> <br> <font size="+1">&nbsp;In: "<i>Innovation &amp; Perspectives in Solid Phase Synthesis &amp; Combinatorial Libraries 2004</i>" (Proceedings of the 8th International Symposium, London), Mayflower Worldwide Ltd,&nbsp; R. Epton, ed., pp 118-122, 2004<font color="#000000">.&nbsp; ISBN 0-9515735-5-1</font></font> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: OligoPrep(TM) was developed as an ideal support for automated solid-phase synthesis of therapeutic phosphorothioate oligonucleotides. Swelling properties, loading of the first nucleoside, and capping and detritylation steps were carefully studied and optimized on the new support. The beads proved to be chemically and mechanically stable under synthesis conditions at a loading of ~250 micromol/g. Synthesis of 20-mer phosphorothioate oligonucleotides at 1 mmol using phosphoramidite chemistry was successful at high product yield and purity.</font></font> <br> </div> <p>&nbsp;&nbsp; <br> </p> <center> <p><b><font size="+2">2005</font></b></p> </center> <p style="text-align: justify;"><font color="#000000"><font size="+1">35) T. Johansson, J. Nilsson, M. Kullberg, G. Laven, M. Sobkowski, A. SzymaDska, M. Szymczak, A. Kraszewski &amp; J. StawiDski.</font></font> <br> <font color="#000000"><font size="+1">"<a href="http://dx.doi.org/10.1081/NCN-200059778">Developing synthetic methods for bioactive phosphorus compounds using&nbsp;<span style="font-style: italic;">H</span>-phosphonate chemistry: A progress report</a>"</font></font> <br> <font size="+1"><i>Nucleosides Nucleotides Nucleic Acids </i><b>24</b>, (5-7), 353-357, 2005</font> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: In this paper a short account of our recent basic studies aiming towards development of new synthetic methods for the preparation of nucleotide analogues using <i>H</i>-phosphonate chemistry is presented.</font></font> </p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font color="#000000"><font size="+1">36) M. Sobkowski, J. Jankowska, J. StawiDski &amp; A. Kraszewski</font></font> <br> <font color="#000000"><font size="+1">"<a href="http://dx.doi.org/10.1081/NCN-200059239">Aryl Nucleoside&nbsp;<span style="font-style: italic;">H</span>-phosphonates as a Tool for Investigation of Stereospecificity During Coupling</a>"</font></font> <br> <font size="+1"><i>Nucleosides Nucleotides Nucleic Acids </i><b>24</b>, (5-7), 887-890, 2005</font> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: It was found that in stereoselective condensations of ribonucleoside 3'-<i>H</i>-phosphonates with alcohols, the major diastereomer of the produced <i>H</i>-phosphonate diesters is formed from the minor diastereomer of the intermediate phosphonic-pivalic anhydride.</font></font> </p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font color="#000000"><font size="+1">37) M. Sobkowski, J. Jankowska, J. StawiDski &amp; A. Kraszewski</font></font> <br> <font color="#000000"><font size="+1">"<a href="http://dx.doi.org/10.1081/NCN-200059759">A Cautionary Note on the Use of the <sup>31</sup>P NMR Spectroscopy in Stereochemical Correlation Analysis</a>"</font></font> <br> <font size="+1"><i>Nucleosides Nucleotides Nucleic Acids </i><b>24</b>, (5-7), 1033-1036, 2005</font> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: Stereoselectivity in condensation of protected ribonucleoside 3'-<i>H</i>-phosphonates with hydroxylic components was investigated using </font><sup><font size="-2">31</font></sup><font size="+0">P NMR spectroscopy. The correlation between absolute configuration at the phosphorus centre and the chemical shifts of the produced H-phosphonate diesters and the corresponding phosphorothioates, was studied.</font></font> </p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font color="#000000"><font size="+1">38) M. Sobkowski, J. StawiDski &amp; A. Kraszewski</font></font> <br> <font color="#000000"><font size="+1">"<a href="http://dx.doi.org/10.1080/15257770500230392">A proposal for a new stereochemical notation for <i>P</i>-chiral nucleotide analogues and related compounds</a>"</font></font> <br> <font size="+1"><i>Nucleosides Nucleotides Nucleic Acids </i><b>24 </b>(9), 1301-1309, 2005.</font> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: A new stereochemical notation for P-chiral nucleotide analogues and related compounds is proposed. In this notation, the names of configurations, designated as <i>D</i></font><sub><font size="-2">P</font></sub><font size="+0"> and <i>L</i></font><sub><font size="-2">P</font></sub><font size="+0">, are derived from a geometrical relationship, rather than from priority rules, of substituents at the phosphorus centre. This new stereochemical description offers clear advantages over the CIP <i>R/S</i> nomenclature, particularly when used for comparing the influence of absolute configuration at the phosphorus centre on physico-chemical and biological properties of oligonucleotide analogues or in stereochemical correlation analysis of <i>P</i>-chiral nucleotide derivatives.</font></font> </p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font color="#000000"><font size="+1">39) M. Sobkowski, J. Jankowska, J. StawiDski &amp; A. Kraszewski</font></font> <br> <font color="#000000"><font size="+1">"<a href="http://dx.doi.org/10.1080/15257770500265729">Stereochemistry of internucleotide bond formation by the <i>H</i>-phosphonate method. 1. Synthesis and <sup>31</sup>P NMR analysis of 16 diribonucleoside (3'-5')-<i>H</i>-phosphonates and the corresponding phosphorothioates</a>"</font></font> <br> <font size="+1"><i>Nucleosides Nucleotides Nucleic Acids </i><b>24</b> (10-12),&nbsp; 1469-1484, 2005</font> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: Sixteen diribonucleoside (3'-5')-<i>H</i>-phosphonates were synthesized via condensation of the protected ribonucleoside 3'-<i>H</i>-phosphonates with nucleosides, and the influence of a nucleoside sequence on the observed stereoselectivity was analyzed. </font><sup><font size="-2">31</font></sup><font size="+0">P NMR spectroscopy was used to evaluate a relationship between chemical shift and absolute configuration at the phosphorus centre of the <i>H</i>-phosphonate diesters as well as of the corresponding phosphorothioate diesters. Although for the most cases such correlation was found, there was however several exceptions to the rule where the relative positions of resonances arising from <i>R</i><sub>P</sub> and <i>S</i><sub>P</sub> diastereomers were reversed.</font></font> <br> &nbsp; </p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font color="#000000"><font size="+1">40) M. Sobkowski, J. Jankowska, J. StawiDski &amp; A. Kraszewski</font></font> <br> <font color="#000000"><font size="+1">"<a href="http://dx.doi.org/10.1135/css200507183">Stereochemistry of internucleotide bond formation by the <i>H</i>-phosphonate method. 2. Transesterification of aryl ribonucleoside <i>H</i>-phosphonate diesters with alcohols</a>"</font></font> <br> <font color="#000000"><font size="+1">In: <i>Collection Symposium Series</i> (M. Hocek, Ed.), <b>7</b>, 183-187, 2005. ISBN 80-86241-25-4</font></font> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: Aryl ribonucleoside 3'-<i>H</i>-phosphonates were used as model compounds in investigations of stereochemistry of an internucleotide bond formation. For all four ribonucleoside 3'-<i>H</i>-phosphonates studied the major diastereomers of the produced <i>H</i>-phosphonate diesters were found to be formed from the minor diastereomers of nucleoside aryl <i>H</i>-phosphonate diesters. These studies indicate the importance of an equilibrium between substrate diastereomers and can be relevant to the stereoselectivity observed in condensation reactions of ribonucleoside <i>H</i>-phosphonates promoted by condensing agents, e.g. pivaloyl chloride.</font></font> <br> <font color="#000000"><font size="+1"><a href="http://users.man.poznan.pl/msob/Transesterification%20of%20aryl%20ribonucleoside%20H-phosphonate.pdf">Full text PDF</a></font></font> </p> <div style="text-align: justify;"> </div> <div style="text-align: justify;"><font color="#000000"><font size="+1">41) M. Sobkowski, J. StawiDski &amp; A. Kraszewski</font></font> <br> <font color="#000000"><font size="+1">"<a href="http://dx.doi.org/10.1135/css200507467">A proposal of <i>D</i></a></font><a href="http://dx.doi.org/10.1135/css200507467"><sub><font size="-1">P</font></sub><font size="+1">/<i>L</i></font><sub><font size="-1">P</font></sub></a><font size="+1"><a href="http://dx.doi.org/10.1135/css200507467"> notation for nucleotide analogues with a chiral phosphorus centre</a>"</font></font> <br> <font color="#000000"><font size="+1">In: <i>Collection Symposium Series</i> (M. Hocek, Ed.), <b>7</b>, 467-469, 2005. ISBN 80-86241-25-4</font></font> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: A proposal of a new notation for <i>P</i>-chiral nucleotide analogues is outlined. In contrast to the absolute <i>R</i></font><sub><font size="-2">P</font></sub><font size="+0">/<i>S</i></font><sub><font size="-2">P</font></sub><font size="+0"> convention, the new <i>D</i></font><sub><font size="-2">P</font></sub><font size="+0">/<i>L</i></font><sub><font size="-2">P</font></sub><font size="+0"> system is based on a geometrical relationship between substituents at the phosphorus atom, and thus appears to be particularly convenient for structural analyses of physical, chemical, and biological properties of nucleotide and oligonucleotide analogues.</font></font> <br> <font color="#000000"><font size="+1"><a href="http://users.man.poznan.pl/msob/A%20proposal%20of%20DPLP%20notation.pdf">Full text PDF</a></font></font> <br> </div> <p>&nbsp;&nbsp; <br> </p> <center> <p><b><font size="+2">2006</font></b></p> </center> <p style="text-align: justify;"><font color="#000000"><font size="+1">42) M. Sobkowski, J. StawiDski &amp; A. Kraszewski</font></font> <br> <font color="#000000"><font size="+1">"<a href="http://dx.doi.org/10.1080/15257770600918862">A proposal for a convenient notation of <i>P</i>-chiral nucleotide analogues. Part 2. Dinucleoside monophosphate analogues</a>"</font></font> <br> <font size="+1"><i>Nucleosides Nucleotides Nucleic Acids </i><b>25</b> (12), 1363-1375, 2006.</font> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: A configuration of ligands around a phosphorus atom in <i>P</i>-chiral dinucleoside monophosphate analogues can be described using <i>D</i></font><sub><font size="-2">P</font></sub><font size="+0">/<i>L</i></font><sub><font size="-2">P</font></sub><font size="+0"> stereochemical notation, which allows immediate correlation between the notation of configuration and the actual spatial arrangement of phosphorus ligands. The area of applications of this new stereochemical nomenclature covers dinucleoside units bridged by virtually any type of tri- and tetra-coordinated phosphorus moieties, i.e. phosphorothioates, phosphoramidates, phosphoramidites, boranophosphates, methanephosphonates, <i>H</i>-phosphonates, and many others.</font></font> </p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font color="#000000"><font size="+1">43) M. Sobkowski, J. StawiDski &amp; A. Kraszewski</font></font> <br> <font color="#000000"><font size="+1">"<a href="http://dx.doi.org/10.1080/15257770600918888">A proposal for a convenient notation of <i>P</i>-chiral nucleotide analogues. Part 3. Compounds with One Nucleoside Residue and Non-Nucleosidic Derivatives</a>"</font></font> <br> <font size="+1"><i>Nucleosides Nucleotides Nucleic Acids </i><b>25</b> (12), 1377-1389, 2006</font> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: Recently, we have proposed a new <i>D</i></font><sub><font size="-2">P</font></sub><font size="+0">/<i>L</i></font><sub><font size="-2">P</font></sub><font size="+0"> stereochemical notation for P-chiral dinucleoside monophosphate analogues that permits simple correlation between spatial arrangement of the substituents and the configuration at the phosphorus center. As an extension of this work, we present here applications of the <i>D</i></font><sub><font size="-2">P</font></sub><font size="+0">/<i>L</i></font><sub><font size="-2">P</font></sub><font size="+0"> notation to derivatives containing only one nucleoside unit</font></font> <br> <font color="#660000"><font size="+0">(e.g., alkyl nucleoside phosphodiesters, nucleoside phosphomonoesters, cyclic phosphate derivatives, nucleoside di-, and triphosphates) and to nonnucleosidic phosphorus compounds.</font></font> <br> </p> <p><font size="+1">44) </font><font color="#000000"><font size="+1">M. Sobkowski</font></font> <br> <font size="+1">"Stereochemistry of internucleotide bond formation by the <span style="font-style: italic;">H</span>-phosphonate method"</font> <br> <font size="+1">Communication presented at "Chemiedozententagung", </font><font size="+1">Hamburg, Germany, 2006</font><font size="+1">.</font> </p> <center> <p><b><font size="+2">2007</font></b></p> </center> <p style="text-align: justify;"><font color="#000000"><font size="+1">45) M. Sobkowski, J. StawiDski &amp; A. Kraszewski</font></font> <br> <font color="#000000"><font size="+1">"<a href="http://www.mrw.interscience.wiley.com/emrw/9780471142706/cp/cpnc/article/nca01e/current/abstract">A Convenient Stereochemical Notation for <i>P</i>-Chiral Nucleotide Analogs</a>"</font></font> <br> <font size="+1">In: <i>Current Protocols in Nucleic Acid Chemistry. APPENDIX 1E</i></font> <br> <i><font size="+1">John Wiley and Sons, Inc.</font></i> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: The <i>D</i></font><sub><font size="-2">P</font></sub><font size="+0">/<i>L</i></font><sub><font size="-2">P</font></sub><font size="+0"> convention is a stereochemical notation for <i>P</i>-chiral nucleotide analogs and related compounds. In contrast to the absolute <i>R</i></font><sub><font size="-2">P</font></sub><font size="+0">/<i>S</i></font><sub><font size="-2">P</font></sub><font size="+0"> notation, the <i>D</i></font><sub><font size="-2">P</font></sub><font size="+0">/<i>L</i></font><sub><font size="-2">P</font></sub><font size="+0"> system is based on a geometrical relationship between substituents in a dinucleoside monophosphate skeleton. The <i>D</i></font><sub><font size="-2">P</font></sub><font size="+0">/<i>L</i></font><sub><font size="-2">P</font></sub><font size="+0"> notation is a convenient alternative to the <i>R</i></font><sub><font size="-2">P</font></sub><font size="+0">/<i>S</i></font><sub><font size="-2">P</font></sub><font size="+0"> notation for stereochemical correlation analysis of physical, chemical, and biological properties of nucleotide and oligonucleotide analogs bearing any type of tri- or tetra-coordinated phosphorus moiety.</font></font> </p> <div style="text-align: justify;"> </div> <div style="text-align: justify;"><font color="#000000"><font size="+1">46) M. Sobkowski, J. StawiDski &amp; A. Kraszewski</font></font> <br> <font color="#000000"><font size="+1">"<a href="http://dx.doi.org/10.1016/j.tetasy.2007.09.017">Stereochemistry of internucleotide bond formation by the <span style="font-style: italic;">H</span>-phosphonate method. 3. Investigations on a mechanism of stereoselectivity induction</a>"</font></font> <br> <i><font size="+1"><font color="#000000">Tetrahedron: Asymmetry</font> </font></i><font size="+1"><b>18</b> (19), 2336-2348</font><font size="+1">, 2007.</font>&nbsp; <br> <font color="#660000"><font size="+0"><u>Abstract</u>: The stereochemistry of condensation of ribonucleoside H-phosphonate monoesters with hydroxylic components has been investigated using 31P NMR spectroscopy. It was found that the reactions owe their stereoselectivity to a dynamic kinetic asymmetric transformation. The relative rates of the equilibration and esterification of the reactive species were evaluated. Absolute configurations of the compounds involved in the reaction pathways were tentatively assigned on the basis of the chemical shifts of their 31P NMR signals. The correctness of the experimental data interpretation was validated for the H-phosphonic-pivalic mixed anhydrides and H-phosphonate active aryl esters.</font></font> <br> </div> <p>&nbsp; <br> </p> <div style="text-align: center;"><b><font size="+2">2008</font></b><br> </div> <p style="text-align: justify;"><font color="#000000"><font size="+1">47) M. Sobkowski<br> </font></font><big>"<a href="http://dx.doi.org/10.1135/css200810277">Diverse chemoselectivity during acylation of nucleosides</a>" </big><br> <font color="#000000"><font size="+1">In: <i>Collection Symposium Series</i> (M. Hocek, Ed.), <b>10</b>, 277-281, 2008. <br> </font></font><font color="#660000"><font size="+0"><u>Abstract</u>: The acylation of nucleosides with acid chlorides under very mild conditions (diluted solution in neutral solvents containing a few equivalents of an amine) was investigated. The rate and the sites of the reaction were found to depend strongly on the kind of amine used. In the presence of DMAP acylation occurred chemoselectively on the hydroxy groups of the ribose moiety, while a mixture of triethylamine and pyridine promoted acylation of the thymine residue.<br> </font></font><font color="#000000"><font size="+1"><a href="../../../../../%7Emsob/Diverse%20chemoselectivity%20during%20acylation%20of%20nucleosides.pdf">Full text PDF</a></font></font><br> </p> <div style="text-align: justify;"> </div> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font color="#660000"><font size="+0"> </font></font></p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font color="#000000"><font size="+1">48) M. Sobkowski, J. StawiDski &amp; A. Kraszewski</font></font><br> <big>"<a href="http://dx.doi.org/10.1016/j.tetasy.2008.11.002">Stereochemistry of internucleotide bond formation by the <span style="font-style: italic;">H</span>-phosphonate method. Part 6. Optimization of the reaction conditions towards highest stereoselectivity</a>"</big><span style="font-size: 14pt; line-height: 150%; font-family: &quot;Times New Roman&quot;;"></span><br> <i><font size="+1"><font color="#000000">Tetrahedron: Asymmetry</font></font></i><big><span style="font-style: italic;"> </span></big><i><font size="+1"> </font></i><font size="+1"><b>19</b> (21)</font><font size="+1">, 2508-2518</font><font size="+1">, 2008.</font>&nbsp; <br> <font color="#660000"><font size="+0"><u>Abstract</u>: The condensations of ribonucleoside 3'-H-phosphonates with simple alcohols and nucleosides are known to be stereoselective reactions that favour formation of </font></font><font color="#660000"><font size="+0"><i>D</i></font><sub><font size="-2">P</font></sub><font size="+0">(<span style="font-style: italic;">S)</span></font><sub><font size="-2">P</font></sub></font><font color="#660000"><font size="+0"> diastereomers of the produced H-phosphonate diesters without engaging any chiral auxiliaries. We have investigated various reaction conditions in order to attain the highest stereoselectivity of the condensation. With an optimal choice of the solvents, reagent concentrations, temperature, and the condensing agent used, the diastereomeric excess of the </font></font><font color="#660000"><font size="+0"><i>D</i></font><sub><font size="-2">P</font></sub><font size="+0">(<span style="font-style: italic;">S)</span></font><sub><font size="-2">P</font></sub></font><font color="#660000"><font size="+0"> isomers of dinucleoside H-phosphonates was enhanced from the initial 50 - 70% to ca. 85%</font></font><font color="#660000"><font size="+0">.</font></font></p> <font color="#660000"><font size="+0"> </font></font> <p><br> </p> <div style="text-align: center;"><b><font size="+2">2009</font></b><br> </div> <p style="text-align: justify;"><font color="#000000"><font size="+1">49) M. Sobkowski, J. StawiDski &amp; A. Kraszewski</font></font><br> <big>"<a href="http://dx.doi.org/10.1039/B812780H">The role of nucleophilic catalysis in chemistry and stereochemistry of ribonucleoside <span style="font-style: italic;">H</span>-phosphonate condensation</a>" (Part 4 of the series "Stereochemistry of internucleotide bond formation by the <span style="font-style: italic;">H</span>-phosphonate method")<br> <span style="font-style: italic;">New. J. Chem. </span><span style="font-weight: bold;">33</span>, 164-170</big><big>, 2009</big><br> <font color="#660000"><font size="+0"><u>Abstract</u>: Efficiency and stereoselectivity of condensations of ribonucleoside 3'-<span style="font-style: italic;">H</span>-phosphonates with alcohols were investigated as a function of amines used as bases. It was found that irrespective of the presence or absence of nucleophilic catalysts, the Dynamic Kinetic Asymmetric Transformation (DYKAT) was the major factor responsible for the stereoselective formation of the <span style="font-style: italic;"></span></font></font><font color="#660000"><font size="+0"><i>D</i></font><sub><font size="-2">P</font></sub><font size="+0">(<span style="font-style: italic;">S)</span></font><sub><font size="-2">P</font></sub></font><font color="#660000"><font size="+0"><span style="font-style: italic;"></span> isomers of the <span style="font-style: italic;">H</span>-phosphonate diesters, and a mechanistic rationalization of this observation was proposed. Studies on the reactions carried out in the presence of various bases led to conclusion that certain sterically hindered pyridines, e.g. 2,6-lutidine, may act as nucleophilic catalysts in the condensation of ribonucleoside 3'-<span style="font-style: italic;">H</span>-phosphonates with alcohols.</font></font></p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font color="#000000"><font size="+1">50) M. Sobkowski, J. StawiDski &amp; A. Kraszewski</font></font> <br> <font color="#000000"><font size="+1">"<a href="http://dx.doi.org/10.1080/15257770802581724">A proposal for a convenient notation of <i>P</i>-chiral nucleotide analogues. Part 4. A relationship between the <span style="font-style: italic;">D</span><sub>P</sub>/<span style="font-style: italic;">L</span><sub>P</sub>&nbsp; notation and stereochemistry of reactions</a>"</font></font> <br> <font size="+1"><i>Nucleosides Nucleotides Nucleic Acids </i><b>28</b> (1), 29-42, 2009</font> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: </font></font><font color="#660000"><font size="+0">Recently, we have proposed a new </font></font><font color="#660000"><font size="+0"><i>D</i></font><sub><font size="-2">P</font></sub><font size="+0">/<i>L</i></font><sub><font size="-2">P</font></sub></font><font color="#660000"><font size="+0"> stereochemical notation for P-chiral dinucleoside monophosphate analogues based on a structural relationship between compounds. As an extension of this work, we present here applications of the </font></font><font color="#660000"><font size="+0"><i>D</i></font><sub><font size="-2">P</font></sub><font size="+0">/<i>L</i></font><sub><font size="-2">P</font></sub></font><font color="#660000"><font size="+0"> notation for tracking stereochemistry of reaction pathways involving <span style="font-style: italic;">H</span>-phosphonate, phosphoramidite, phosphorotriester, and other intermediates frequently met in the nucleotide chemistry.<br> </font></font></p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font color="#000000"><font size="+1">51) J. Romanowska, A. SzymaDska-Michalak, M. Pietkiewicz, M. Sobkowski, J. Boryski, J. StawiDski &amp; Adam Kraszewski</font></font> <br> <font color="#000000"><font size="+1">"<a href="http://dx.doi.org/10.2174/157017809789124821">A New, Efficient Entry to Non-Lipophilic <span style="font-style: italic;">H</span>-Phosphonate Monoesters - Preparation of Anti-HIV Nucleotide Analogues</a>"</font></font> <br> <font size="+1"><i>Letters in Organic Chemistry </i><span style="font-weight: bold;">6</span> (6), 496-499, 2009</font> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: </font></font><font color="#660000"><font size="+0">Crystalline ammonium (9<span style="font-style: italic;">H</span>-fluoren-9-yl)methyl <span style="font-style: italic;">H</span>-phosphonate was prepared by a new, simple method and it was used as the reagent of choice for the introduction of an <span style="font-style: italic;">H</span>-phosphonate monoester functionality into non-lipophilic anti-HIV nucleoside analogues.</font></font><br> </p> <div style="text-align: justify;"> </div> <p style="text-align: justify;"><font color="#660000"><font size="+0"><br> </font></font></p> <div style="text-align: center;"><b><font size="+2">2010<br> </font></b> <p style="text-align: justify;"><font color="#000000"><font size="+1">52) M. Sobkowski</font></font><br> <font color="#000000"><font size="+1">"<a href="http://dx.doi.org/10.1135/cccc2009084">A convenient protection for 4-oxopyrimidine moiety in nucleosides by the pivaloyl group</a>"</font></font><br> <font size="+1"><i>Collection of Czechoslovak Chemical Communications </i></font><font size="+1"><span style="font-weight: bold;">75</span> </font><font size="+1">(1), 33-57, 2010</font> <br> <font color="#660000"><font size="+0"><u>Abstract</u>: </font></font><font color="#660000"><font size="+0">Application of the pivaloyl group as a protection for the N3 position of thymidine and uridine was investigated. Pivaloylation of thymidine is a very rapid reaction proceeding under mild conditions with excellent regioselectivity for sugar or thymine moiety, depending on the amines used. Several pivaloylated thymidine derivatives were obtained by treatment of unprotected thymidine with pivaloyl chloride under various experimental conditions. Stability of the <span style="font-style: italic;">N</span>3-pivaloyl protecting group under basic and acidic conditions was evaluated and the conditions for its selective removal were found</font></font><font color="#000000"><font size="+1">.</font></font></p> <p style="text-align: justify;"><font color="#000000"><font size="+1">53) M. Sobkowski</font></font><font color="#000000"><font size="+1">, J. StawiDski &amp; A. Kraszewski</font></font><br> <big>"<a href="http://dx.doi.org/10.1016/j.tetasy.2010.01.022">Stereochemistry of internucleotide bond formation by the <span style="font-style: italic;">H</span>-phosphonate method. 7. Stereoselective formation of ribonucleoside (<span style="font-style: italic;">R</span><sub>P</sub>)- and (<span style="font-style: italic;">S</span><sub>P</sub>)-3'-<span style="font-style: italic;">H</span>-phosphonothioate monoesters</a>"<br> <span style="font-style: italic;"></span></big><i><font size="+1"><font color="#000000">Tetrahedron: Asymmetry</font></font></i><big><span style="font-style: italic;"></span></big><big><span style="font-style: italic;"> </span><span style="font-weight: bold;">21</span> </big><big>(4), 410-419, 2010</big><br> <font color="#660000"><font size="+0"><u>Abstract</u>: </font></font><font color="#660000"><font size="+0">Ribonucleoside 3'-<span style="font-style: italic;">H</span>-phosphonothioate monoesters exist in a form of <span style="font-style: italic;">R</span><sub>P</sub> and<span style="font-style: italic;"> </span></font></font><font color="#660000"><font size="+0"><span style="font-style: italic;">S</span><sub>P</sub> diastereomers</font></font><font color="#660000"><font size="+0">. In order to obtain them in good yields and in high stereochemical purity, stereoselective strategies for their preparation were investigated. For the synthesis of the </font></font><font color="#660000"><font size="+0"><span style="font-style: italic;">R</span><sub>P</sub> </font></font><font color="#660000"><font size="+0">isomer a stereoselective sulfhydrolysis of an activated nucleoside <span style="font-style: italic;">H</span>-phosphonate was developed, while the monoesters having having <span style="font-style: italic;">S</span><sub>P</sub> configuration were prepared by asymmetric transformation of diastereomeric mixtures of nucleoside 3'-<span style="font-style: italic;">H</span>-phosphonothioates using either a condensation&nbsp; with 9-fluorenemethanol, followed by its beta-elimination, or via pivaloylation-hydrolysis reaction sequence. A tentative assignment of absolute configurations of the obtained diastereomers of 3'-<span style="font-style: italic;">H</span>-phosphonothioate esters was done via a stereochemical correlation analysis.</font></font><br> </p> <p style="text-align: justify;"><font color="#000000"><font size="+1">54) M. Sobkowski</font></font><br> <big>"<a href="http://dx.doi.org/10.1039/B9NJ00679F">Chemistry and stereochemistry of internucleotide bond formation by the <span style="font-style: italic;">H</span>-phosphonate method</a>" (<span style="font-style: italic;">Perspective</span>)<br> <span style="font-style: italic;">New. J. Chem. </span><span style="font-weight: bold;">34</span> </big><big>(5), 854-869, 2010</big><br> <font color="#660000"><font size="+0"><u>Abstract</u>: The appropriately protected ribonucleoside 3'-<span style="font-style: italic;">H</span>-phosphonates react with nucleosides and alcohols in the presence of condensing agents under mild conditions, with a notable stereoselectivity. Chemistry and stereochemistry of this reaction were investigated using <sup>31</sup>P NMR spectroscopy. A plausible mechanism for the asymmetric induction observed was identified as Dynamic Kinetic Asymmetric Transformation (DYKAT) operating due to different esterification rates of rapidly equilibrating P-epimers of the reactive intermediates. This diverse reactivity was tentatively attributed to steric demands of the <span style="font-style: italic;">H</span>-phosphonic moiety located in the vicinity of bulky protecting group in the 2' position. The role of nucleophilic and base catalysis was analysed and the absolute configuration of the intermediates involved in the reaction pathways was tentatively assigned using </font></font><font color="#660000"><font size="+0"><sup>31</sup>P </font></font><font color="#660000"><font size="+0">NMR stereochemical correlation analysis. With an optimal choice of the reaction conditions the diastereomers of dinucleoside <span style="font-style: italic;">H</span>-phosphonate diesters could be obtained usually in &gt;90:10 ratio.</font></font><br> </p> <p style="text-align: justify;"><font color="#000000"><font size="+1">55) M. Sobkowski, J. StawiDski &amp; A. Kraszewski</font></font> <br> <font color="#000000"><font size="+1">"</font></font><a href="http://www.informaworld.com/openurl?genre=article&amp;issn=1525%2d7770&amp;volume=29&amp;issue=8&amp;spage=628"><span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;" lang="EN-GB">Stereochemistry of internucleotide bond formation by the <i style="">H-</i>phosphonate method. </span><font color="#000000"><font size="+1"> </font></font><span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;" lang="EN-GB">5. The role of Br<span style="">onsted and H-bonding </span>base catalysis in ribonucleoside <i style="">H-</i>phosphonate condensation - chemical and stereochemical consequences</span></a><font color="#000000"><font size="+1">"</font></font> <br> <font size="+1"><i>Nucleosides Nucleotides Nucleic Acids</i></font><big><span style="font-style: italic;"> </span><span style="font-weight: bold;">29</span> </big><big>(8), 628-645, 2010</big><br> <font color="#660000"><font size="+0"><u>Abstract</u>: </font></font><font color="#660000"><font size="+0">Efficiency and stereoselectivity of condensations of ribonucleoside 3'-<span style="font-style: italic;">H</span>-phosphonates with ethanol promoted by pivaloyl chloride were investigated as a function of tertiary amines used. Side reactions leading to an increased demand for the condensing agent were identified as derived from an attack of the pivalate anion at carbonyl centres of reactive pivaloyl derivatives. The conditions that secured quantitative yields of <span style="font-style: italic;">H</span>-phosphonate diester condensations were assessed. Several tertiary amines promoted condensations with stereoselectivity higher than that observed for pyridine derivatives. A correlation between diastereoselectivity of the product formation and Bronsted and H-bonding basicities of the amine used was found</font></font><font color="#660000"><font size="+0">.<br> </font></font></p> <p style="text-align: justify;"><font color="#660000"><font size="+0"><br> </font></font></p> <b><font size="+2">2011</font></b> <p style="text-align: justify;"><font color="#000000"><font size="+1">56) M. Sobkowski, J. Jankowska, J. StawiDski &amp; A. Kraszewski</font></font><br> <font color="#000000"><font size="+1">"<a href="http://dx.doi.org/10.1080/10426507.2010.503212"><span style="font-family: &quot;times new roman&quot;;">Unusual stereochemistry of esterification of uridine 3'-<span style="font-style: italic;">H</span>-phosphonothioate</span></a></font></font><span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;" lang="EN-GB"></span><font color="#000000"><font size="+1">"</font></font> <br> <font size="+1"><i>Phosphorus, Sulfur and Silicon </i></font><span style="font-weight: bold;">186 </span>(4), 952-955, 2011<br> <font color="#660000"><font size="+0"><u>Abstract</u>: According to <sup>31</sup>P NMR correlation analysis, reactive derivatives of uridine 3'-<span style="font-style: italic;">H</span>-phosphonothioate react with O-nucleophiles probably with retention of configuration</font></font><font color="#660000"><font size="+0">.<br> </font></font></p> <p style="text-align: justify;"><font color="#000000"><font size="+1">57) J. Romanowska, M. Sobkowski</font></font><font color="#000000"><font size="+1">, A. SzymaDska-Michalak</font></font><font color="#000000"><font size="+1">, K. KoBodziej, A. Dbrowska, A. Lipniacki, A. Piasek, Z.M. Pietrusiewicz, M. Figlerowicz, A. Guranowski, J. Boryski, J. StawiDski &amp; A. Kraszewski</font></font> <br> <font color="#000000"><font size="+1">"<a href="http://dx.doi.org/10.1021/jm2001103">Aryl H-Phosphonates 17: (<span style="font-style: italic;">N</span>-Aryl)phosphoramidates of Pyrimidine Nucleoside Analogues and Their Synthesis, Selected Properties, and Anti-HIV Activity</a>"</font></font> <br> <cite>J. Med. Chem.,</cite><font size="+1"><i> </i><span style="font-weight: bold;"></span></font><span class="citation_year"></span><span style="font-weight: bold;" class="citation_volume">54</span> (19), 6482-6491, 2011<br> <font color="#660000"><font size="+0"><u>Abstract</u>: New synthetic protocol for the preparation of nucleoside 5'-(<span style="font-style: italic;">N</span>-aryl)phosphoramidate monoesters 4 was developed. It consisted of a condensation of the corresponding nucleoside 5'-<span style="font-style: italic;">H</span>-phosphonates with aromatic- or heteroaromatic amines promoted by diphenyl phosphorochloridate, followed by oxidation of the produced H-phosphonamidates with iodine/water. 5'-(<span style="font-style: italic;">N</span>-Aryl)phosphoramidate monoesters derived from 3'-azido-3'-deoxythymidine (AZT) or 2',3'-dideoxyuridine (ddU) nucleosides and various aromatic and heteroaromatic amines were evaluated as potential anti-HIV drugs. If was found that these compounds act most likely as pronucleotides, and some of them have therapeutic indices superior to those of the reference AZT</font></font><font color="#660000"><font size="+0">.</font></font></p> <div style="text-align: justify;"> </div> <div style="text-align: justify;"> </div> <br> <b><font size="+2">2012</font></b><font color="#000000"><font size="+1"><br> </font></font> <br> <div style="text-align: justify;"><font color="#000000"><font size="+1">58) </font></font><font color="#000000"><font size="+1">J. </font></font><font color="#000000"><font size="+1">Romanowska</font></font><font color="#000000"><font size="+1">, </font></font><font color="#000000"><font size="+1">K. KoBodziej, </font></font><font color="#000000"><font size="+1">M. Sobkowski &amp; </font></font><font color="#000000"><font size="+1">A. Kraszewski</font></font><br> <font color="#000000"><font size="+1">"</font></font><span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;">Nukleozydo (<span style="font-style: italic;">N</span>-arylo)amidofosforany - nowe wysoce aktywne i nietoksyczne pronukleotydy anty-HIV"</span><br> <span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;">Poster presented at "55. Zjazd PTChem i SITPChem" conference, September 16-20, 2012, BiaBystok, Poland</span><br> <span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;">Conference proceedings, S05P26, p. 199</span><br> </div> <br> <b><font size="+2">2013</font></b><font color="#000000"><font size="+1"><br> </font></font> <div style="text-align: left;"><font color="#000000"><font size="+1"><span style="font-family: &quot;times new roman&quot;;"></span></font></font><span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;"></span><font color="#000000"><font size="+1">59) K. KoBodziej &amp; M. Sobkowski</font></font><br> <font color="#000000"><font size="+1">"</font></font><span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;">Aryl nucleoside phosphoramidates as new anti-HIV prodrugs"<br> </span><font color="#000000"><font size="+1"><span style="font-family: &quot;times new roman&quot;;"><span style="font-style: italic;">BioTechnologia,</span> <span style="font-weight: bold;">94</span> (1), 80, </span></font></font><font color="#000000"><font size="+1"><span style="font-family: &quot;times new roman&quot;;">2013</span></font></font><span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;"><br> <br> </span><font color="#000000"><font size="+1">60) <span style="font-family: &quot;times new roman&quot;;">M. Materna &amp; M. Sobkowski<br> "Stereochemistry of phosphorylating agents comprising nucleophilic catalytic groups"<br> <span style="font-style: italic;">BioTechnologia,</span> <span style="font-weight: bold;">94</span> (1), 86, </span></font></font><font color="#000000"><font size="+1"><span style="font-family: &quot;times new roman&quot;;">2013</span></font></font><br> <span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;"><br> </span><font color="#000000"><font size="+1">61) <span style="font-family: &quot;times new roman&quot;;"></span></font></font><font color="#000000"><font size="+1">J. </font></font><font color="#000000"><font size="+1">Romanowska</font></font><font color="#000000"><font size="+1">, </font></font><font color="#000000"><font size="+1">M. Sobkowski &amp; </font></font><font color="#000000"><font size="+1">A. Kraszewski</font></font><br> <font color="#000000"><font size="+1"><span style="font-family: &quot;times new roman&quot;;">"New type of anti-HIV phosphoramidate prodrugs"<br> <span style="font-style: italic;">BioTechnologia,</span> <span style="font-weight: bold;">94</span> (1), 94, </span></font></font><font color="#000000"><font size="+1"><span style="font-family: &quot;times new roman&quot;;">2013</span></font></font><br> <span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;"><br> </span><font color="#000000"><font size="+1">62) M. Materna, M. Sobkowski &amp; J. StawiDski<br> "</font></font><span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;">Stereochemia czynnikw fosforylujcych zawierajcych nukleofilowe grupy katalityczne"<br> Poster presented at "56. Zjazd PTChem i SITPChem" conference, September 16-20, 2013, Siedlce, Poland<br> Conference proceedings, S01P114, p. 185<br> </span><font color="#000000"><font size="+1"><br> 63) K. KoBodziej, M. Sobkowski, J. StawiDski &amp; </font></font><font color="#000000"><font size="+1">A. Kraszewski </font></font><br> <font color="#000000"><font size="+1">"</font></font><span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;">Nukleozydo (<span style="font-style: italic;">N</span>-arylo)amidofosforany, potencjalne pronukleotydy anty-HIV"<br> Poster presented at "56. Zjazd PTChem i SITPChem" conference, September 16-20, 2013, Siedlce, Poland<br> </span><span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;">Conference proceedings, S05P32, p. 402</span><br> <span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;"> <br> 64) </span><font color="#000000"><font size="+1">M. Sobkowski<br> "Diastereoselective esterification of ribonucleoside 3'-<span style="font-style: italic;">H</span>-phosphonates"<br> Communication presented at "Towards a New RNA Word" conference, November 12-14, 2013, PoznaD, Poland<br> </font></font></div> <br> <br> <center><b><font size="+2">2014<br> <br> </font></b></center> <div style="text-align: justify;"> <div style="text-align: justify;"> <font size="+1">65) M. Materna, J. </font><font color="#000000"><font size="+1">StawiDski </font></font><font size="+1">&amp; M. Sobkowski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1135/css201414322"><span style="font-style: italic;">N</span>-Oxides as reagents in nucleotide chemistry</a>"</font> <br> <font size="+1">In: <i>Collection Symposium Series</i> (M. Hocek, Ed.), <b>14</b>, 322-323, 2014.</font> <br> <font color="#660000"><u>Abstract:</u> <span style="font-style: italic;">N</span>-Oxides were investigated as oxidants of <span style="font-style: italic;">H</span>-phosphonates. These compounds are powerful nucleophiles and are able to substitute leaving groups at phosphorus centers rapidly. The produced putative ammonio intermediates of type P-O-N<sup>+</sup>R<sub>3</sub> collapse rapidly with the O-N bond fission making the <span style="font-style: italic;">N</span>-oxide efficient donors of the oxygen atom to reactive <span style="font-style: italic;">H</span>-phosphonates.</font> <br> </div> <br> <font size="+1">66) M. Materna, J. </font><font color="#000000"><font size="+1">StawiDski </font></font><font size="+1">&amp; M. Sobkowski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1135/css201414369">Trialkylamine <span style="font-style: italic;">N</span>-Oxides as Reagents in Nucleotide Chemistry</a>"</font> <br> <font size="+1">In: <i>Collection Symposium Series</i> (M. Hocek, Ed.), <b>14</b>, 369-372, 2014.</font> <br> <font color="#660000"><u>Abstract:</u> Trialkylamine <span style="font-style: italic;">N</span>-oxides were introduced to the chemistry of phosphorus and nucleotide derivatives. These compounds are powerful nucleophiles and are able to substitute leaving groups in phosphorus centers rapidly. The putatively produced ammonio intermediates of type P-O-N<sup>+</sup>R<sub>3</sub> collapse rapidly with O-N bond fission making the <span style="font-style: italic;">N</span>-oxide investigated efficient donors of the oxygen atom to reactive <span style="font-style: italic;">H</span>-phosphonates and halogenophosphates. Synthetic applications of these reactions are outlined.</font> <br> </div> <br> <div style="text-align: left;"><font size="+1">67) K. </font><font size="+1">KoBodziej</font><font size="+1">, A. Kraszewski, J. </font><font color="#000000"><font size="+1">StawiDski </font></font><font size="+1">&amp; M. Sobkowski</font> <br> </div> <div style="text-align: left;"><font size="+1">"<a href="http://dx.doi.org/10.1135/css201414373">The Loss of TEAH<sup>+</sup> Cation From Certain Nucleotide Analogues</a>"</font> <br> </div> <div style="text-align: left;"><font size="+1">In: <i>Collection Symposium Series</i> (M. Hocek, Ed.), <b>14</b>, 373-374, 2014.</font> <br> </div> <div style="text-align: justify;"><font color="#660000"><u>Abstract:</u> During chromatographic purification and evaporation of solvents, triethylammonium salts of phosphate esters and amides may loose the cation yielding new species differing in chemical and physical properties.</font> <br> </div> &nbsp; <br> <div style="text-align: left;"><font size="+1">68) </font><font color="#000000"><font size="+1">J. Romanowska, M. Ro|niewska, M. Sobkowski</font></font><font color="#000000"><font size="+1">, A. SzymaDska-Michalak</font></font><font color="#000000"><font size="+1">, A. Dbrowska, A. Lipniacki, A Piasek, J. Boryski, J. StawiDski &amp; A. Kraszewski</font></font> <br> <font size="+1">"Wspolczesne koncepcje pronukleotydow anty-HIV"</font> <br> <span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;">Poster presented at "57. Zjazd PTChem i SITPChem" conference, September 14-18, 2014, Czstochowa, Poland</span><br> <span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;"> </span><span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;">Conference proceedings, S04W02, p. 197</span><br> <br> <font size="+1">69) M. Materna, J. </font><font color="#000000"><font size="+1">StawiDski </font></font><font size="+1">&amp; <span style="text-decoration: underline;">M. Sobkowski</span></font> <br> <font size="+1">"Trialkylamine <span style="font-style: italic;">N</span>-oxides in nucleotide chemistry"</font> <br> <big><span style="font-family: &quot;times new roman&quot;;"></span></big><span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;">Oral presentation at "XXI Round Table on Nucleosides, Nucleotides and Nucleic Acids" conference, August 24-28, 2014, PoznaD, Poland</span><br> <span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;"> </span><span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;">Conference proceedings, p. OP17</span><br> <br> <font size="+1">70) M. Materna, J. </font><font color="#000000"><font size="+1">StawiDski </font></font><font size="+1">&amp; M. Sobkowski</font> <br> <font size="+1">"<i>N</i>-Oxides in the synthesis of nucleotide analogues"</font> <br> <span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;">Poster presented at "XXI Round Table on Nucleosides, Nucleotides and Nucleic Acids" conference, August 24-28, 2014, PoznaD, Poland</span><br> <span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;"> </span><span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;">Conference proceedings, p. 37</span><br> <br> <font size="+1">71) M. Materna, J. StawiDski &amp; M. Sobkowski</font> <br> <font size="+1">"Oxidative dehalogenation of halogenophosphates by <i>N</i>-oxides in the synthesis of nucleotide analogues"</font> <br> <span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;">Poster presented at "XXI Round Table on Nucleosides, Nucleotides and Nucleic Acids" conference, August 24-28, 2014, PoznaD, Poland</span><br> <span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;"> </span><span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;">Conference proceedings, p. 38</span><br> <span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;"></span></div> <span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;"> </span><br> <center><b><font size="+2">2015</font></b></center> <br> <div style="text-align: left;"><font size="+1">72) K. KoBodziej, J. Romanowska, J. StawiDski, A. Kraszewski &amp; M. Sobkowski</font><br> <font size="+1">"<a href="http://dx.doi.org/10.1007/s00216-014-8397-0">The case of triethylammonium cation loss during purification of certain nucleotide analogues. A cautionary note</a>" </font><br> <font size="+1"> <i>Analytical &amp; Bioanalytical Chemistry</i>, <span style="font-weight: bold;">407</span> (6), 1775-1780, 2015. </font><br> <font size="+1"> <small><span style="color: rgb(0, 153, 0);">Open Access</span></small></font><br> </div> <div style="text-align: justify;"><font color="#660000"><u>Abstract:</u> Nucleotides, their analogues, and other phosphate esters and phosphoramidates often contain triethylammonium cation as a counterion. We found that this may be lost during chromatographic purification or concentration of solutions, yielding products in acidic forms or containing sub-stoichiometric amounts of the counterion. This in turn may be detrimental e.g. due to possible decomposition of a compound or inaccurate sample preparation. Correlations between the structure of studied compounds and their susceptibility for cation loss were analyzed. Modifications in preparative techniques were developed to obtain the studied compounds with stoichiometric anion:cation ratios.</font>&nbsp; <br> </div> <br> <div style="text-align: left;"><font size="+1">73) M. Sobkowski,A. Kraszewski &amp; J. StawiDski</font><br> <font size="+1">"<a href="http://dx.doi.org/10.1007/128_2014_562">Recent Advances in <i>H</i>-Phosphonate Chemistry. Part 1. <i>H</i>-Phosphonate Esters: Synthesis and Basic Reactions</a>" </font><br> <font size="+1"> <i>Topics in Current Chemistry</i>, <span style="font-weight: bold;">361</span> (Phosphorus Chemistry II), 137-177, 2015.</font> <br> <div style="text-align: justify;"><font color="#660000"><u>Abstract:</u> This review covers recent progress in the preparation of <span style="font-style: italic;">H</span>-phosphonate mono- and diesters, basic studies on mechanistic and stereochemical aspects of this class of phosphorus compounds, and their fundamental chemistry in terms of transformation of P H bonds into P-heteroatom bonds. Selected recent applications of <span style="font-style: italic;">H</span>-phosphonate derivatives in basic organic phosphorus chemistry and in the synthesis of biologically important phosphorus compounds are also discussed.</font> <br> </div> <br> <font size="+1">74) M. Sobkowski, A. Kraszewski &amp; J. StawiDski</font><br> <font size="+1">"<a href="http://dx.doi.org/10.1007/128_2014_563">Recent Advances in <i>H</i>-Phosphonate Chemistry. Part 2. Synthesis of C-Phosphonate Derivatives</a>" </font><br> <font size="+1"> <i>Topics in Current Chemistry</i></font><font size="+1">, <span style="font-weight: bold;">361</span> (Phosphorus Chemistry II), 179-216, 2015.</font> <br> <div style="text-align: justify;"><font color="#660000"><u>Abstract:</u> This chapter provides an overview of recent advances in the development of new methods and protocols for the formation of the P C bond using <span style="font-style: italic;">H</span>-phosphonate diesters as starting materials. Various chemical and stereochemical aspects of the transition metal-catalyzed cross-coupling and organocatalyst-promoted reactions which are relevant to the synthesis of structurally diverse <span style="font-style: italic;">C</span>-phosphonate derivatives are surveyed.</font>&nbsp; <br> </div> <br> <font size="+1">75) K. KoBodziej, J. Romanowska, J. StawiDski, J. Boryski, A. Dbrowska, A. Lipniacki, A. Piasek, A. Kraszewski M. Sobkowski</font><br> <font size="+1">"<a href="http://dx.doi.org/10.1016/j.ejmech.2015.06.004">Aryl <span style="font-style: italic;">H</span>-Phosphonates 18. Synthesis, properties, and biological activity of 2',3'-dideoxynucleoside (<span style="font-style: italic;">N</span>-heteroaryl)phosphoramidates of increased lipophilicity</a>" </font><br> <font size="+1"> <i>European Journal of Medicinal Chemistry</i></font><font size="+1">, <span style="font-weight: bold;">100</span>, 77-88, 2015.</font> <br> <div style="text-align: justify;"><font color="#660000"><u>Abstract:</u> Recently, AZT (<span style="font-style: italic;">N</span>-pyridyl)phosphoramidates were reported as a new type of potential anti-HIV therapeutics. In continuation of that work, here we present new (<span style="font-style: italic;">N</span>-heteroaryl)phosphoramidate derivatives of antiviral 2',3'-dideoxynucleosides containing other types of <span style="font-style: italic;">N</span>-heteroaryl moieties, particularly those with higher lipophilicity. The present studies comprise mechanistic investigations using <sup>31</sup>P NMR correlation analysis, which permitted improvements in the synthetic procedures. The obtained compounds were tested in biological systems to establish their cytotoxicity and anti-HIV activity. The results were analyzed with respect to possible correlations between biological and physico-chemical properties of the phosphoramidates studied, to get some insight into their antiviral mode of action.</font> <br> </div> <br> <font size="+1">76) M. Materna, J. StawiDski &amp; M. Sobkowski</font><br> <font size="+1">"Zastosowanie <span style="font-style: italic;">N</span>-tlenkw w syntezie analogw nukleotydw"</font><br> <font size="+1">Poster presented at "58. Zjazd PTChem i SITPChem" conference, September 21-25, 2015, GdaDsk, Poland</font><br> <font size="+1">Conference proceedings, S03P162, p. 162</font> <br> <br> <font size="+1">77) M. Materna, J. StawiDski &amp; M. Sobkowski</font><br> <font size="+1">"<span style="font-style: italic;">N</span>-Oxides in the synthesis of nucleotide analogues"</font><br> <font size="+1">Poster presented at "Recent Advances in Nucleic Acids Therapeutics" conference, October 15-16, 2015, Adz, Poland</font><br> <font size="+1">Conference proceedings, p. P6</font><br> <font size="+1"> </font><br> <font size="+1"> </font> <font size="+1">78) A. Kraszewski, J. Romanowska, M. Sobkowski, A. SzymaDska-Michalak, J. StawiDski, J. Boryski, A. Lipniacki &amp; A. Piasek</font><br> <font size="+1">"<a href="http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&amp;Sect2=HITOFF&amp;d=PALL&amp;p=1&amp;u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&amp;r=1&amp;f=G&amp;l=50&amp;s1=9206209.PN.&amp;OS=PN/9206209&amp;RS=PN/9206209">New nucleotide analogues useful as an anti-HIV pro-nucleotide against HIV virus and for producing antiviral drug for treating HIV infections including AIDS</a>"</font><br> <font size="+1">United States Patent US 9206209<br> </font> <center><b><font size="+2">2016<br> <br> </font></b></center> 79<font size="+1">) M. Materna, J. </font><font color="#000000"><font size="+1">StawiDski</font></font><font size="+1">, A. Kiliszek, W. Rypniewski &amp; M. Sobkowski</font> <br> <font size="+1">"<a href="http://dx.doi.org/10.1039/C5RA27465F">Oxyonium phosphobetaines  unusually stable nucleophilic catalyst-phosphate complexes formed from <span style="font-style: italic;">H</span>-phosphonates and <span style="font-style: italic;">N</span>-oxides</a>"</font> <br> <font size="+1"><span style="font-style: italic;">RSC Advances</span></font><font size="+1">, <span style="font-weight: bold;">6</span> (18), 14448-14451, 2016</font><font size="+1">.</font> <br> <font color="#660000"><u>Abstract:</u> Aryl <span style="font-style: italic;">H</span>-phosphonates react with <span style="font-style: italic;">N</span>-oxides to form previously unknown stable zwitterionic oxyonium phosphates comprising an <sup>"</sup>O P O N<sup>+</sup>Z atom system. Their structures were confirmed <span style="font-style: italic;">i.a.</span> by X-ray crystal structure analysis, and some mechanisms were proposed for their formation. Stability during storage and reactivity toward nucleophiles point to their possible synthetic applications.</font> <br> <font size="+1"><br> 80) M. Materna, J. </font><font color="#000000"><font size="+1">StawiDski </font></font><font size="+1">&amp; M. Sobkowski</font> <br> <font size="+1">"Nucleoside oxyonium phosphobetaines  reactive phosphate complexes in new synthetic strategies for biologically active nucleotide analogues"</font> <br> <span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;">Poster presented at "XXII Round Table on Nucleosides, Nucleotides and Nucleic Acids" conference, July 18-25, 2016, Paris, France</span><br> <span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;"> </span><span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;">Conference proceedings, p. 234</span><br> <br> <font size="+1">81) M. Materna, J. StawiDski &amp; M. Sobkowski</font> <br> <font size="+1">"Applications of <span style="font-style: italic;">N</span>-oxides in the chemistry of nucleotide analogues"</font> <br> <span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;">Poster presented at "XXII Round Table on Nucleosides, Nucleotides and Nucleic Acids" conference, July 18-25, 2016, Paris, France</span><br> <span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;"> </span><span style="font-size: 14pt; font-family: &quot;Times New Roman&quot;;">Conference proceedings, p. 252</span><br> <font size="+1"> </font></div> </div> </blockquote> <a href="http://users.man.poznan.pl/msob/INDEX2.html"><img src="back.gif" align="texttop" height="20" width="19"></a><font size="+1"><a href="http://users.man.poznan.pl/msob/INDEX2.html"> home page</a></font> </body> </html>