Chiral lithium amido sulfide ligands for asymmetric addition reactions of alkyllithium reagents to aldehydes

摘要

Six chiral amino sulfides have been synthesised from the amino acids phenylalanine. phenylglycine and valine. These amino sulfides were used as chiral ligands in the asymmetric addition of n-butyllithium and metyllithium to various aldehydes at low temperatures. The highest stereoselectivities were obtained with berizaldehyde. resulting in 1-phenyl-1-pentanol and 1-phenyl-1-ethanol in enantiomeric excesses of > 98.5 and 95% respectively. These stereoselectivities were significantly, higher than those induced by the ether analogues. (C) 2003 Elsevier Science Ltd. All rights reserved. [References: 49]