THE HWE REACTION IN SOLID - LIQUID TWO PHASE SYSTEM FOR THE SYNTHESIS OF α,β-UNSATURATED AMIDES

Abstract

The Homer-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 α,β-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.

Key Words:

• Diethyl ester of 2-amino-2-oxoethylphosphonic acid
• diethyl ester of 2-diethylamino-2-oxoethylphosphonic acid
• Homer-Wadsworth-Emmons reaction
• α,β-unsaturated amides
• solid-liquid two phase system