Acyl-Imidazoles: A Privileged Ester Surrogate for Enantioselective Synthesis

Graphical Abstract

What a privilege! Since their first use in asymmetric Friedel-Crafts reactions, acyl-imidazoles have appeared as powerful ester/amide surrogates. Indeed, the imidazole moiety displays stability and special activation features that allow enhanced reactivity and selectivity in traditional ester/amide functionalization. An overview of the contemporary and growing interest for acyl-imidazoles in metal- and organo-catalyzed transformations, as well as post-functionalization expediencies will be highlighted.

Abstract

Since the first report by Evans in asymmetric Friedel-Crafts reactions, the use of acyl-imidazoles has blossomed as powerful ester/amide surrogates. The imidazole scaffold indeed displays stability and special activation features allowing both better reactivity and selectivity in traditional ester/amide functionalizations: α-(enolate chemistry), β-(conjugate additions), α,β-(cycloadditions) or γ/δ-(vinylogous). An overview of the contemporary and growing interest in acyl-imidazoles in metal- and organo-catalyzed transformations (bio-hybrid catalytic systems will be fully described in a back-to-back Minireview) will be highlighted. Moreover, post-functionalization expediencies are also going to be discussed in this Minireview.