MnO₂‐Promoted Oxidative Radical Sulfonylation of Haloalkynes with Sulfonyl Hydrazides: C(sp)–S Bond Formation towards Alkynyl Sulfones

Abstract

A catalyst-free oxidative radical sulfonylation of haloalkynes with sulfonyl hydrazides is reported. It represents an example of C(sp)-S bond formation using sulfonyl hydrazides as sulfonyl radical sources. Various alkynyl sulfones were synthesized in moderate to good yields. Having MnO₂ as the oxidant is very critical for this transformation. Remarkably, the self-coupling reaction of haloalkynes through C(sp)-C(sp) bond formation is significantly inhibited under the standard reaction conditions.