Organocatalytic regioselective, diastereoselective, and enantioselective annulation of cyclic 1-azadienes with γ-nitro ketones via 3,4-cyclization

Abstract

A regio-, diastereo-, and enantioselective [2 + 4] annulation reaction of cyclic 1-azadienes with γ-nitro ketones is reported. In the presence of a chiral tertiary amine, the annulation reaction proceeded smoothly to furnish polysubstituted cyclohexanes in 43–95% yields with 80–98% ee via 3,4-addition. Notably, four consecutive stereocenters including one tetrasubstituted carbon stereocentre could be constructed in one-pot via this methodology.