Recent advances in the sulfonylation of C–H bonds with the insertion of sulfur dioxide

Abstract

Recent advances in the sulfonylation of C–H bonds with the insertion of sulfur dioxide are summarized. Usually, a sulfur dioxide surrogate, DABCO·(SO₂)₂, is used, which avoids the utilization of gaseous sulfur dioxide in the transformation. Inorganic sulfites such as sodium metabisulfite are also effective in C(sp³)–H bond sulfonylation. C–H bond sulfonylation under transition metal catalysis or through a radical process has been developed. In some cases, the sulfonylation can be performed under catalyst- and additive-free conditions, or can be facilitated by visible light irradiation. The efficiency is also investigated by merging the radical process and metal catalysis.