ELECTROORGANIC CHEMISTRY .129. ELECTROREDUCTIVE SYNTHESIS OF CHIRAL PIPERAZINES AND ENANTIOSELECTIVE ADDITION OF DIETHYLZINC TO ALDEHYDES IN THE PRESENCE OF THE CHIRAL PIPERAZINES

Electroreduction of diimines, prepared from 1,2-diamines and aromatic aldehydes, in acidic media gave intramolecularly coupled products, 2,3-diarylpiperazines, stereoselectively. Chiral tri- and tetrasubstituted piperazines were synthesized effectively from chiral 1,2-diamines by the same electroreductive method. Chiral piperazines, prepared from 1(R),2(R)-diaminocyclohexane were effective chiral ligands of catalysts for the enantioselective addition of diethylzinc to aldehydes.