Organic Catalytic Oxa-Michael–Aldol Cascade Reaction for the Asymmetric Synthesis of (R)-2-Phenyl-2H-chromene-3-carbaldehyde

Catalyzed by a chiral cyclohexanediamine-based organocatalyst, the asymmetric oxa-Michael–aldol cascade reaction of salicylaldehyde and cinnamaldehyde was studied to synthesize benzopyran derivatives. Using (1R,2R)-N1,N1-dimethylcyclohexane-1,2-diamine (Cat 1) as the catalyst, the synthesized chiral 2-aryl-2H-chromenes-3-carbaldehyde exhibits high yields (up to 85%) and with enantioselectivity (ee) values of 35.4%. The high yield and mild reaction conditions are some of the important features of this protocol.