An Efficient Synthesis of Chiral Diamines with Rigid Backbones: Application in Enantioselective Michael Addition of Malonates to Nitroalkenes

A new and efficient route for synthesis of enantiomerically pure biisoindoline and its isomer based on the diaza-Cope rearrangement reaction with chiral 1,2-bis(2-hydroxylphenyl)-1,2-diaminoethane as starting material has been developed. The newly prepared biisoindoline was employed as a chiral ligand in the NI(II)-catalyzed enantioselective Michael addition of malonates to conjugated nitroalkenes, and good to excellent enantioselectivities were obtained.