Journal of the American Chemical Society, Vol.138, No.36, 11481-11484, 2016
Efficient Enantioselective Synthesis of Oxahelicenes Using Redox/Acid Cooperative Catalysts
An efficient and enantioselective synthesis of oxa[9]helicenes has been established via vanadium(V)-catalyzed oxidative coupling/intramolecular cyclization of polycyclic phenols. A newly developed vanadium complex cooperatively functions as both a redox and Lewis acid catalyst to promote the present sequential reaction and afford oxa[9]helicenes in good yields with up to 94% ee.