A convenient method for the preparation of chiral phosphonoacetamides and their Horner-Wadsworth-Emmons reaction

摘要

Chiral phosphonoacetamides bearing (S)-(alpha-methylbenzyl) benzylamine, (S,S)-bis(alpha-methylbenzyl) amine, L-phenylglycine methyl ester and L-phenylglycinol were easily prepared in good yield by means of the Michaelis-Arbuzov reaction of chiral bromo-acetamides obtained in quantitative yield, with trimethyl phosphite, which under Horner-Wadsworth-Emmons conditions with several aryl and alkyl aldehydes under Masamune-Roush procedure using LiCl and DBU in THF or toluene gave the corresponding chiral alpha,beta-unsaturated amides. The present procedure is a convenient and efficient methodology for the preparation of phosphonoacetamides and chiral alpha,beta-unsaturated amides in high E-selectivity. (c) 2007 Elsevier Ltd. All rights reserved.