Copper-Catalyzed Regio- and Stereoselective Sulfonylation of Alkynyl Imines with Sulfonyl Hydrazides: Access to (E)-β-Sulfonyl Enones

Abstract

A copper-catalyzed sulfonylation of alkynyl imines with sulfonyl hydrazides has been developed, which exhibited excellent regio- and stereoselectivity and furnished a series of (E)-β-sulfonyl enones in moderate to good yields. Mechanistic studies suggest that this strategy goes through a radical process.

Dehydroxylative Sulfonylation of Alcohols

“…Therefore, the synthesis of sulfones has received considerable attention and the past few years have witnessed some of the most important and revolutionizing advances in the field of sulfonylation . A wide range of sulfonylation reagents have been developed, such as sulfur dioxide, sulfonyl hydrazides, and sulfinic acids and their salts, for the formation of various C–SO 2 bonds. Despite these accomplishments, it is still highly desirable to develop mild and efficient protocols for the direct conversions of common functional groups into sulfonyl groups.…”

Catalyst-Controlled Direct Oxysulfonylation of Alkenes by Using Sulfonylazides as the Sulfonyl Radical

“…In the past several years, the bifunctionalization of olefins has been a powerful tool in organic synthesis, which has allowed the introduction of two functional groups to the CC bonds. As part of our continuous effort to pursue radical-mediated sulfonylation and inspired by the work of Lam and Zeng, we hypothesized the sulfonyl radicals could be generated in situ from the sulfonyl azides under oxidized conditions. Followed by radical addition of olefins, radical–radical coupling would produce the difunctionalization products.…”