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

Structure and assembly of the S-layer in C. difficile

Many bacteria and archaea possess a two-dimensional protein array, or S-layer, that covers the cell surface and plays crucial roles in cell physiology. Here, we report the crystal structure of SlpA, the main S-layer protein of the bacterial pathogen Clostridioides difficile, and use electron microscopy to study S-layer organisation and assembly. The SlpA crystal lattice mimics S-layer assembly in the cell, through tiling of triangular prisms above the cell wall, interlocked by distinct ridges facing the environment. Strikingly, the array is very compact, with pores of only ~10 Å in diameter, compared to other S-layers (30–100 Å). The surface-exposed flexible ridges are partially dispensable for overall structure and assembly, although a mutant lacking this region becomes susceptible to lysozyme, an important molecule in host defence. Thus, our work gives insights into S-layer organisation and provides a basis for development of C. difficile-specific therapeutics

Reactions Catalysed by a Binuclear Copper Complex: Aerobic Cross Dehydrogenative Coupling of N-Aryl Tetrahydroisoquinolines

A hybrid bioorganic interface for neuronal photoactivatio