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.