Phosphine-Catalyzed Nucleophilic Ring Opening of Cyclopropenones with Sulfoximines to Access

Herein, we describe the formation of biologically relevant N-α,β-unsaturated acyl sulfoximines via phosphine-catalyzed C-C bond activation of cyclopropenones with weakly nucleophilic sulfoximines. The new process does not require a transition metal or external oxidant and displays high regioselectivity and exclusive E-selectivity. Other salient features of the method are a broad substrate scope, high compatibility with various functional groups, and high atom economy.