Microwave assisted cobalt(iii)-catalysed C–H aminocarbonylation reactions with isocyanates for the synthesis of thiophenecarboxamides

Abstract

A mild and efficient cobalt(III)-catalysed C–H aminocarbonylation procedure for thiophenes and benzo[b]thiophenes under MW assisted conditions has been developed. Site selectivity is controlled by the use of pyridine and pyrimidine directing groups. The reaction is effective with aromatic isocyanates with wide substitution patterns, although aliphatic isocyanates showed less reactivity. The introduced amide group can act as directing group in further iterative C–H functionalization reactions, allowing the diversification of the heterocyclic structures. DFT calculations have shed light on the mechanistic course and reactivity patterns.