Vicinal 1,2-difunctionalization of alkynones and alkynoates with glycosyl thiosulfonates: Stereoselective synthesis of fully substituted glycosylthio-functionalized α,β-Unsaturated sulfones.

Abstract

A simple and efficient vicinal 1,2-glycosylthiosulfonylation of alkynones and alkynoates has been developed using readily accessible glycosyl thiosulfonates under metal-free conditions. Under the catalysis of 10 mol% Cs2CO3, a broad range of alkynones and alkynoates underwent smooth Michael addition/nucleophilic substitution reactions with glycosyl thiosulfonates, enabling the simultaneous formation of C-S and C-SO2 bonds in a one-pot process. This protocol provides efficient access to fully substituted glycosylthio-functionalized α,β-unsaturated sulfones as valuable glycomimetic scaffolds in high yields with E-selectivity. The reaction proceeds under mild conditions, exhibits a broad substrate scope, high atom economy, and excellent functional group compatibility. Furthermore, the method was successfully applied to gram-scale synthesis, highlighting its practicality and synthetic utility.