Development of a Catalytic Ester Activation Protocol for the Efficient Formation of Amide Bonds using an Ar-I/HF center dot pyridine/mCPBA System

A new catalytic approach for the activation of esters, that possess a p-hydroxyphenyl group as a potential activating group on the ester residue, was developed and applied to the efficient synthesis of amides and peptides. A characteristic feature of this protocol is the in-situ generation of a hypervalent iodine(III) species using an Ar-I/HF center dot pyridine/mCPBA system. A reactive acyl fluoride intermediate is smoothly generated via the oxidative dearomatization of phenols in the presence of a catalytic amount of 4-iodoanisole, thereby affording various amides and peptides including sterically hindered derivatives.