Asymmetric synthesis. Part 29: Asymmetric hydroformylation of styrene catalyzed by chiral spiro diphosphite-rhodium(I) complexes

摘要

Chiral diphosphite ligands L-1-L-3 were prepared by the reaction of (1S,5S,6R)-(cis,trans)-spiro[4.4]nonane-1,6-diol with chlorophosphites. These ligands were tested in the rhodium catalyzed hydroformylation of styrene and enantioselectivities up to 69% were achieved. High regioselectivities (97%) to 2-phenylpropanal and high yields (98%) were obtained under mild reaction conditions. The influence of reaction conditions is also discussed. (C) 1998 Elsevier Science Ltd. All rights reserved. [References: 11]