The HWE reaction in solid-liquid two phase system for the synthesis of alpha,beta-unsaturated amides

摘要

The Horner-Wadsworth-Emmons (HWE) reaction of the diethyl ester of 2-amino-2-oxoethylphosphonic acid 1 as well as of diethyl ester of the 2-dimethylamino-2-oxoethylphosphonic acid 2 with some aldehydes and ketones 3 in liquid-solid two phase system is used for the preparation of alpha,beta -unsaturated amides 4, 5. The synthesis is carried out in mild conditions (room temperature, KOH, K2CO3, CaO) in the absence of a catalyst or in the absence of a solvent, and leads in very high (E)-stereoselectivity and in high yields to en-amides. [References: 38]