Transition-metal-free insertion of alkynes into the C-C σ-bond of cyclic β-keto sulfones: an atom-economical way to medium-size-ring sulfonyl derivatives

A novel base-promoted and highly efficient strategy for the preparation of medium-size-ring sulfonyl derivatives has been developed. This method is realized by alkynes insertion into the C-C σ-bond of cyclic β-keto sulfones, introducing sulfonyl groups into medium-size-ring compounds. This reaction possesses competitive features such as broad substrate scope, transition-metal-free and atom economy.