Dearomative Dienolate-Mediated Catalysis: A Remote Activation Strategy for Asymmetric Functionalization of Benzylic C–H Bonds of Heteroaryl Aldehydes

A dearomative remote activation strategy for the asymmetric functionalization of benzylic C–H bonds of heteroaryl aldehydes under bifunctional Brønsted base catalysis has been developed. The in situ generated o-QDMs-type dienolate intermediates were efficiently and stereoselectively trapped by nitroolefins through an asymmetric Michael/nitro-aldol cascade reaction. Using this strategy, a wide variety of synthetically significant tetrahydro­dibenzo­thiophene and tetrahydro­dibenzo­furan derivatives were synthesized in good yields with high enantioselectivities.