An efficient platform for decarboxylative functionalization of carboxylic acids using sulfuryl fluoride: Pd-catalyzed decarboxylative dehydrogenation of alkanecarboxylic acids and decarboxylative cross-coupling of arenecarboxylic acids†

Decarboxylation functionalization of carboxylic acids has evolved to valuable synthetic methods because of the structural diversity of carboxylic acids and their utility in drug discovery as directing groups for C–H activation. Although transition-metal-catalyzed decarboxylation is one of the most common methods, it typically requires complex operations and additives within a limited substrate scope. In this study, we show that the use of a palladium-catalyzed system together with sulfuryl fluoride can readily effect decarboxylative dehydrogenation and decarboxylative cross-coupling of various alkyl and aryl carboxylic acids. Based on mechanistic studies including DFT calculations, a detailed catalytic cycle is presented in which rapid generation of an acyl fluoride from the reaction of SO₂F₂ with a carboxylic acid is critical for initiating catalysis. The versatility of a new mediator platform has been demonstrated with a diverse range of substrates and applications.