Photoredox catalytic alkylarylation of alkynes with arylsulfonylacetate as bifunctional reagent

Difunctionalization of alkynes represents a powerful and straightforward approach to the synthesis of complex molecules. However, the radical difunctionalization of alkynes mediated by bifunctional reagents remains challenging and underexplored, despite significant progress having been made in alkene difunctionalization. Here, we report a novel arylsulfonylacetate skeleton in which aryl rings are attached to acetates through SO₂, serving as a powerful bifunctional reagent for the alkylarylation of alkynes via vinyl-radical intermediate under photoredox conditions. This modular bifunctional reagent enables the simultaneous incorporation of a wide range of functional groups, including (hetero)aryl ring and alkyl carboxylate into alkynes, resulting in synthetically valuable all-carbon tetrasubstituted alkene derivatives. This transformation is distinguished by its redox-neutral nature, readily accessible starting materials, compatibility with diverse functional groups and its capacity to facilitate convergent synthesis. The utility of this approach was further demonstrated by the late-stage functionalization of complex molecules and the preparation of fluorescent molecules and anti-cancer drugs.