Acylation of Rhodium(III) Porphyrin Complexes with Carboxylic Acids: Scope and Mechanism

Rhodium(III) porphyrin complexes undergo C(=O)-O bond activation (COA) of carboxylic acids to give the corresponding rhodium(III) porphyrin acyl complexes Rh-III(ttp)COR up to 90% yield. Mechanistic studies suggested either a sigma-bond metathesis reaction or 1,2-addition between an active rhodium(III) porphyrin hydride species, Rh-III(ttp)-H, and the carboxylic acid (R(C=O)-OH) to give the corresponding Rh-III(ttp)COR product.

Automated summary

Rhodium(III) porphyrin complexes can activate C(=O)-O bonds of carboxylic acids, yielding Rh(III) porphyrin acyl complexes Rh-III(ttp)COR with up to 90% yield. Mechanistic studies suggest either a sigma-bond metathesis reaction or 1,2-addition between active Rh(III) porphyrin hydride species, Rh-III(ttp)-H, and carboxylic acids to form the corresponding Rh-III(ttp)COR product.