α-Regioselective [3 + 2] annulations with Morita–Baylis–Hillman carbonates of isatins and 2-nitro-1,3-enynes†
Abstract
An α-regioselective asymmetric [3 + 2] annulation reaction with Morita–Baylis–Hillman carbonates of isatins and (E)-2-nitro-1,3-enynes catalysed by cinchona-derived amines has been developed, providing spirooxindoles with contiguous chiral centres including adjacent quaternary ones in moderate to good yields with high enantioselectivity and excellent diastereoselectivity.