Synthesis of 2-pyranosyl benzothiazoles, benzimidazoles and benzoxazoles via nucleophilic addition reactions of pyranosyl nitrile oxides
作者:Iain A.S. Smellie、Andreas Fromm、Francesca Fabbiani、Iain D.H. Oswald、Fraser J. White、R. Michael Paton
DOI:10.1016/j.tet.2010.06.076
日期:2010.8
Reaction of per-O-acetylated-β-d-pyranosyl nitrileoxides, generated by dehydrochlorination of the corresponding hydroximoyl chlorides, with 2-aminothiophenol afforded 2-(β-d-pyranosyl)benzothiazoles. 1,2-Diaminobenzene and 2-aminophenol reacted similarly to yield 2-(β-d-pyranosyl)benzimidazoles and 2-(β-d-pyranosyl)benzoxazoles, respectively. The structures of 2-β-d-glucopyranosylbenzimidazole (17)
Preparing glycosyl benzothiazoles from 2-isocyanoaryl thioethers and glycosyl radicals under thermal conditions
作者:Daqi Liu、Yang Zhang、Dawen Niu
DOI:10.1039/d4cc00648h
日期:——
Herein, we report a method for preparing glycosyl benzothiazoles via radical cascade cyclization, in which glycosyl radicals are generated from readily available and bench-stable allyl glycosyl sulfones. This cascade reaction proceeds under simple conditions and tolerates a broad substrate scope in high yield with excellent stereoselectivity. Mechanistic studies support that the reactions proceed via