Organocatalytic Asymmetric Michael Addition of 3-Pyrrolyloxindoles to beta-Phthalimidonitroethene for the Synthesis of 3,3 '-Disubstituted Oxindoles Bearing Contiguous 3,alpha,beta-Triamino Functionality

An organocatalytic asymmetric Michael addition reaction of 3-pyrrolyloxindoles to beta-phthalimidonitroethene has been developed with a bifunctional thiourea tertiary amine as the catalyst. A range of 3,3'-disubstituted oxindoles bearing contiguous 3,alpha,beta-triamino functionality could be obtained in high yields with good diastereoselectivities and high enantioselectivities (up to 99% yield, 99:1 dr, and 98% ee). The higher reactivity of beta-phthalimidonitroethene compared to the reactivity of ordinary nitroalkenes in the reaction experiments. with 3-pyrrolyloxindoles was demonstrated by contras