Catalytic enantioselective construction of all-carbon quaternary stereocenters by an organocatalytic Diels–Alder reaction of α-substituted α,β-unsaturated aldehydes

A binaphthyl-based primary amine (R)- was designed for the Diels-Alder reaction of alpha-substituted alpha,beta-unsaturated aldehydes; in the presence of the TfOH salt of (R)-, the Diels-Alder reaction of alpha-substituted alpha,beta-unsaturated aldehydes with cyclopentadiene proceeded to afford the corresponding cycloadducts having one all-carbon quaternary stereocenter in good yield with good to high stereoselectivity.