Enantioselective Construction of Vicinal Diaxial Styrenes and Multiaxis System via Organocatalysis.

A highly diastereo- and enantioselective methodology for the asymmetric synthesis of vicinal diaxial styrenes and multiaxis system was achieved by organocatalysis. Various vicinal diaxial styrenes and multiaxis systems were obtained in excellent enantioselective manners. The mechanism studies revealed that a new tetra-substituted vinylidene ortho-quinone methide (VQM) intermediate was likely involved and accounted for the excellent enantioselectivity.