Acyl-Imidazoles A Privileged Ester Surrogate for Enantioselective Synthesis

International audienceSince 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

DNA-Based Asymmetric Inverse Electron-Demand Hetero-Diels-Alder

International audienceWhile artificial cyclases hold great promise in chemical synthesis, this work presents the first example of a DNA-catalyzed inverse electron-demand hetero-Diels-Alder (IEDHDA) between dihydrofuran and various α,β-unsaturated acyl imidazoles. The resulting fused bicyclic O,O-acetals containing three contiguous stereogenic centers are obtained in high yields (up to 99 %) and excellent diastereo- (up to >99:1 dr) and enantioselectivities (up to 95 % ee) using a low catalyst loading. Most importantly, these results show that the concept of DNA-based asymmetric catalysis can be expanded to new synthetic transformations offering an efficient, sustainable, and highly selective tool for the construction of chiral building blocks