Enantioselective synthesis and use in catalytic asymmetric addition of diethylzinc to benzaldehyde of new chiral cyclic hydroxyamino ferrocene and chromium complexes:: influence of the complexation on the enantioselectivity

The optically active (arene)chromium complexes (+)-(S,1S)-7-13, (+)-(S,1S)-20 and ferrocenyl amino alcohol (+)-(S,1S)-14-17 were synthesized from enantiomerically pure tricarbonyl(1-indanone)chromium (ee>98), tricarbonyl(1-tetralone)chromium (ee>99) and 1,2-(alpha-oxotetramethylene)ferrocene (ee>98). These compounds were used as chiral catalysts in the asymmetric addition of diethylzinc to benzaldehyde: 1-phenylpropanol has been obtained in up to 70% enantiomeric excess. The influence of the metallic group on the enantioselectivities has been studied. (C) 1998 Elsevier Science Ltd. All rights reserved.