Synthesis of Acyclic Nucleoside Analogues through the Insertion of Carbenoids into N−H Bond of Nucleobases

Abstract

An ew and efficient approachf or the synthesis of acyclic nucleoside analogues with differents ide chains has been established for the first time via the insertion of carbenoidsi nto NÀHb ond of nucleobases. With Sc(OTf) 3 as the catalyst, various purine bases and a-diazoesters worked well, and gave the corresponding acyclic nucleosides in moderate-to-good yields (21 examples, up to 87 % yield) with good N9-regioselectivities(up to > 99:1). Moreover,o ther N-heterocycles including pyrimidines, benzoimidazole, imidazole, carbazole, and pyrazolea re also suitable substrates and afford the desired NÀHi nsertion products with moderate-to-good yields. In addition, the enantioselectivea nd chiral auxiliary induction NÀHi nsertion reactions were also studied.

“All-Aqueous” Tandem Boc-Deprotection and Alkylation of N-Bocbenzimidazole Derivatives under Visible Light with Alkyl Aryl Diazoacetates: Application to Site-Selective Insertion of Carbenes into the N–H Bond of Purines

“…They are also important intermediates in the synthesis of numerous ionic liquids . Hence, various strategies have been devised for the N 1 -alkylation of benzimidazole derivatives . Among the reported strategies, the noteworthy ones include the reaction of alkyl halide and anhydrous potassium or cesium carbonate in polar organic solvents or using powdered KOH in acetone at room temperature (with or without 18-crown-6). − Alternatively, the condensation of an o -phenylene diamine with diverse aromatic aldehydes in various solvents including on water provided the desired N 1 -alkylated benzimidazoles .…”

Expedient synthesis and biological evaluation of alkenyl acyclic nucleoside phosphonate prodrugs

“…16,17 Discovered almost 30 years ago, a great wealth of research has been dedicated to the development of efficient synthetic methodologies that resulted in a great variety of ANPs. [18][19][20][21][22] These new structures offer a potential for the discovery of more effective drugs against a variety of infectious diseases including antiparasitic, [23][24][25][26][27][28][29] antimicrobial, [30][31][32][33] and antitubercolous 34,35 medicines. Among these synthetic strategies, quite recently, Agrofoglio's group has elaborated a novel, efficient and straightforward synthesis of C5-alkenyl substituted ANPs via olefin cross-metathesis.…”