CATALYTIC ASYMMETRIC REDUCTIVE AMINATION OF KETONES VIA HIGHLY ENANTIOSELECTIVE HYDROGENATION OF THE C=N DOUBLE-BOND

We describe a convenient, chemoselective asymmetric reductive aminatio n procedure for the conversion of ketones to chiral hydrazines and ami nes. The key step in the three-step process is enantioselective DuPHOS -Rh-catalyzed hydrogenation of the C=N double bond of N-acylhydrazones . Detailed optimization studies revealed the effect of solvent, temper ature, and the N-acyl group on the enantioselectivity and catalytic ef ficiency of the reaction. The reduction products, N-acylhydrazines, we re converted to hydrazines or amines through hydrolysis or treatment w ith samarium(II) iodide, respectively.