Solid-phase synthesis of oligonucleotides having a fully-modified stereoregular phosphorothioate backbone or a stereoregular phosphate/phosphorothioate chimeric backbone was achieved by using diastereopure nucleoside 3'-bicyclic oxazaphospholidine derivatives and beta-cyanoethyl phosphoramidites as monomer units and N-(cyanomethyl)pyrrolidinium trifluoromethanesulfonate (CMPT) as an acidic activator. The trans-isomers of the oxazaphospholidines were obtained exclusively by the reaction of the 3'-OH of appropriately protected nucleosides and the corresponding 2-chloro-1,3,2-oxazaphospholidine derivative. The trans-isomers were configurationally stable and did not epimerize almost at all even in the presence of CMPT. As a result, the formation of phosphorothioate internucleotide linkages using the oxazaphospholidine derivatives and CMPT proceeded without any loss of diastereopurity. In addition to the synthesis of stereoregular phosphorothioate linkages, the synthesis of phosphate internucleotide linkages through the same method was studied. As a result of the study, stereoregular phosphate/phosphorothioate chimeric oligonucleotides as well as stereoregular oligonucleoside phosphorothioates were efficiently synthesized by using the same method.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1093/nass/nrn169 | DOI Listing |
Org Biomol Chem
September 2023
Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
In this study, we developed a new approach for the solid-phase synthesis of oligodeoxynucleotides (ODNs) using nucleobase-unprotected oxazaphospholidine derivatives. We tackled the problem of the difficult purification of -unprotected monomers due to their high affinity to silica gel by introducing a tetrahydrogeranyl group into the oxazaphospholidine monomers, thereby enhancing the lipophilicity and facilitating the isolation. In addition, the cyclic structure of oxazaphospholidine enabled a hydroxy-group-selective condensation with sufficient efficiency.
View Article and Find Full Text PDFR Soc Open Sci
April 2023
Department of Medicinal and Life Sciences, Tokyo University of Science, Noda, Chiba 278-8510, Japan.
This study describes the stereoselective synthesis of boranophosphate/phosphate (PB/PO) and phosphorothioate/phosphate (PS/PO) chimeric oligouridylates using the solid-phase method. Oxazaphospholidine monomer was used to construct the stereodefined PB and PS linkages. The study introduces modifications to oligouridylate derivatives in the intended positions with the intended stereochemistry of phosphorous atoms.
View Article and Find Full Text PDFCarbohydr Res
August 2022
Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan. Electronic address:
N-Trichloroacetyl analogs of N-acetylmannosamine 1-phosphate repeating units, which are found in capsular polysaccharides of Neisseria meningitidis serotype A, were successfully obtained via solid-phase synthesis using an oxazaphospholidine monomer. The introduction of the trichloroacetyl group into the amino group of mannosamine resulted in the stabilization of the reaction intermediates. Monosaccharide, disaccharide, and tetrasaccharide derivatives were obtained and isolated.
View Article and Find Full Text PDFACS Omega
August 2021
Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
Glycosyl phosphate repeating units can be found in the glycoconjugates of some bacteria and protozoa parasites. These structures and their P-modified analogs are attractive synthetic targets as antimicrobial, antiparasitic, and vaccine agents. However, P-modified glycosyl phosphates exist in different diastereomeric forms due to the chiral phosphorus atoms, whose configuration would highly affect their physiochemical and biochemical properties.
View Article and Find Full Text PDFJ Org Chem
November 2020
Université de Bourgogne-Franche-Comté, Institut de Chimie Moléculaire (ICMUB-OCS, UMR-CNRS 6302), BP 47870, Dijon 21078 Cedex, France.
We have recently patented an unprecedented stereospecific N → O phosphinyl migration process which transforms P-chirogenic aminophosphines into phosphinites. A fine design of aminophosphine phosphinite ligands (AMPP*) derived from ephedrine and bearing a P-chirogenic center either at the aminophosphine or phosphinite moiety was performed. The synthesis of AMPP* ligands with a P-chirogenic aminophosphine moiety was based on the well-established stereospecific reaction of oxazaphospholidine borane with organolithium reagents, followed by trapping with a chlorophosphine and borane decomplexation.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!