Chiral lithium amido sulfide ligands for asymmetric addition reactions of alkyllithium reagents to aldehydes
作者:Johan Granander、Richard Sott、Göran Hilmersson
DOI:10.1016/s0957-4166(02)00864-9
日期:2003.2
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.