Photo-induced tandem cyclization of alkynes with sodium sulfinates to access sulfonated exocyclic alkenes

Abstract

A novel visible-light-induced sulfonylation/cyclization of alkynes was developed, without transition metal catalysis and a photocatalyst. This is the first reported work on constructing sulfone-containing exocyclic alkenes via sulfonyl radical-initiated cyclization of alkynes. This cascade reaction yields naphtho[1,8-bc]thiophenes with the advantages of mild reaction conditions, simple operation and good functional group tolerance.