Organocatalyzed O-glycosylation of glycosyl trichloroacetimidates donors: l-prolinethioamide as brønsted acid catalyst

Abstract

In this study, we present the utilization of l-proline-derived thioamide small organic molecules as an effective organocatalyst for the O-glycosylation of various glycosyl trichloroacetimidate donors, eliminating the need for any cocatalysts or additives. The catalytic process achieves high yields with a wide array of alcohol and sugar nucleophiles, demonstrating a broad substrate scope and operational simplicity under mild reaction conditions. Preliminary mechanistic investigations indicate that l-prolinethioamide facilitates the glycosylation reaction via Brønsted acid/base catalysis, involving the formation of a catalyst–acceptor adduct.