Enantioselective addition of diethylzinc to aldehydes catalyzed by monosubstituted [2.2]paracyclophane-based N,O-ligands: remarkable cooperative effects of planar and central chiralities

Diastereomeric monosubstituted [2.2]paracyclophane-based N,O-ligands, which unite the planar and central chiral elements, were optimized for the enantio selective diethylzinc addition to aldehydes. (S)-1-{(S-p)-[2.2]Paracyclophan-4-yl} methyl-2-pyrrolidine-alpha,alpha-diphenylmethanol (S-p,S)-3 catalyzed the addition to give (R)-1-phenyl-l-propanol in a high yield and with a good enantio selectivity (91% ee). (c) 2006 Elsevier Ltd. All rights reserved.