Visible-light-induced organocatalytic enantioselective N-H insertion of α-diazoesters enabled by indirect free carbene capture.

While asymmetric insertion of metal carbenes into H-X (X = C, N, O, ) bonds has been well-established, asymmetric control over free carbenes is challenging due to the presence of strong background reactions and lack of any anchor for a catalyst interaction. Here we have achieved the first photo-induced metal-free asymmetric H-X bond insertion of this type. With visible light used as a promoter and a chiral phosphoric acid used as a catalyst, α-diazoesters and aryl amines underwent smooth N-H bond insertion to form enantioenriched α-aminoesters with high efficiency and good enantioselectivity under mild conditions.