N-Heterocyclic carbene-/photoredox-catalyzed regioselective carbonylation of alkenes†

Abstract

Besides its special reactivities, organocatalysis offers the notable advantage of avoiding metal residue compared with metal catalysis, and N-heterocyclic carbenes are important organocatalysts. Recently, the combination of NHC organocatalysis and photoredox catalysis has emerged as a promising strategy for C–C bond formation via radical intermediates. However, very few organocatalysis strategies can be used in carbonylation chemistry, especially using N-heterocyclic carbene as it gets deactivated by carbon monoxide. Herein, for the first time, we developed a catalytic carbonylation strategy combining NHC catalysis with photocatalysis to enable CO-involved regioselective synthetic transformation. Under standard conditions, carbonylative diacylation of alkenes was realized to afford valuable 1,4-dicarbonyl compounds in good yields. This strategy offers novel insights into the design of photoinitiated organocatalytic transformations of carbon monoxide.