Acyl-Imidazoles: A Privileged Ester Surrogate for Enantioselective Synthesis

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: alpha-(enolate chemistry), beta-(conjugate additions), alpha,beta-(cycloadditions) or gamma/delta-(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.