Enantioselective addition of alkyllithium reagents to aldehydes induced by chiral lithium alkoxides

Article abstract of DOI:10.1016/S0040-4020(01)90462-4

Enantioselective induction by some chiral lithium alkoxides in the addition of methyllithium to benzaldehyde has been examined. A detailed study of 2-substituted lithium 1-phenyl-2-(N,N-dimethylamino)-ethoxides in the addition of achiral alkyllithium reagents to aldehydes in THF and diethyl ether at -78°C has been carried out. The ee's are generally higher in the former solvent. The configuration of the newly formed chiral center is opposite to that of the 1-carbon of the alkoxide and independent of that of its 2-carbon atom. The ee of the product is generally increased by increasing the size of 2-substituent. Enantioselectivity is decreased by the addition of LiCl and LiClO₄ but is little affected by the presence of the predominant enantiomer of the lithium alkoxide produced in the reaction.