Synthesis of Novel 1,4-Bissulfonamide Ligands for Enantioselective Addition of Diethylzinc to Aldehydes

摘要

Several novel chiral sulfonamide ligands based on (1R,2S,4R,5S)-1,4-diamino-2,5-dimethylcyclohexane skeleton have been synthesized and their application in the enantioselective addition of diethylzinc to aldehydes was investigated in the presence of Ti(OiPr)₄. The effect of ligands, temperature and the loading amount of ligands was studied. Under optimized conditions, enantioselective addition of diethylzinc with various aryl aldehydes and aliphatic aldehydes proceeded smoothly and afforded chiral secondary alcohols in up to 88% ee.