Visible-light promoted cascade cyanoalkylsulfonylation/ipso-cyclization of N-arylpropiolamides toward sulfonated spiro[4,5]trienones via SO2 insertion

Abstract

A novel visible-light induced sulfonylation/ipso-cyclization of N-arylpropiolamides with cyclobutanone oxime esters and Na₂S₂O₅ was reported. This protocol proceeded via a radical process. The wide substrate scope, sustainable metal-free conditions and readily accessible reagents make this protocol an efficient and green strategy for the synthesis of cyanoalkyl sulfonated spiro[4,5]trienones.