Photocatalytic Annulation-Alkynyl Migration Strategy for Multiple Functionalization of Dual Unactivated Alkenes.

A novel photoredox catalysis for multiple functionalization of two different types of unactivated alkenes in a single operation was reported through a conceptually new mode of annulation-alkynyl migration. A wide array of cyclopentane carboxylates were synthesized in a highly selective and functional-group-compatible manner via C-centered radical induced cascade 5-exo-trig/5-exo-dig bicyclization and C-C bond cleavage process. This methodology might open a new entry for designing annulation-functional group migration to create structurally applicable cyclic ring systems.