Visible light-mediated formal alkylation and [4+1]-cycloaddition strategies of silyl enol ethers with aryldiazoacetates.

Abstract

A reaction sequence of visible light-mediated cyclopropanation/acid-promoted ring-opening is described for the formal alkylation of silyl enol ethers with aryldiazoacetates. Under the same conditions, the Danishefsky's diene can react with aryldiazoacetates to afford [4+1]-cycloaddition adducts. Key mechanistic aspects are proposed based on experimental evidence and DFT calculations.