Solid-supported ortho-iodoarylboronic acid catalyst for direct amidation of carboxylic acids

Amides are a ubiquitous class of organic compounds endowed with great utility. There is a need for simple and effective catalytic methods for their direct formation from carboxylic acids and amines as a way to avoid the use of coupling reagents. We have designed a recyclable resin-supported derivative of 5-methoxy-2-iodophenylboronic acid as a heterogeneous catalyst active in ambient conditions for promoting direct amidations of aliphatic carboxylic acids and amines. The optimal, practical procedure involves a simple double-filtration to isolate the amide product while separating the catalyst from residual molecular sieves.