Direct Estirification and Amidation of Phosphinic Acids Under Microwave Conditions

Abstract

Phosphinic acids may be efficiently esterified in microwave-assisted reactions with alcohols. Especially alcohols with longer alkyl chain are suitable reagents for direct esterifications. At the same time, the direct amidation cannot be complete under such conditions. Hence, the tradional amidations via the phosphinic chloride intermediates have to be applied. The values of activation enthalpies and reaction enthalpies obtained by quantum chemical calculations justified the experimental observations. Microwave has a potential in overcoming relatively high activation enthalpies.