Histidine-derived N-heterocyclic Carbenes in Metal Peptide Conjugates for Abiotic Catalysis.

Histidinium (Hum), a N,N'-dimethylated variant of histidine, serves as a non-canonical amino acid that provides an N-heterocyclic carbene (NHC) binding site for metal coordination. This amino acid therefore allows for combining peptides and proteins with NHC metal complexes, one of the most prolific scaffolds of homogeneous catalysis of the recent past. Here, we review our efforts in combining these two areas by constructing chemically synthesized tetrapeptide NHC rhodium conjugates for hydrosilylation and larger peptide metal systems obtained from solid phase peptide synthesis for abiotic iridium-catalysed hydrogenation of ketones.