Toward a General Protocol for Catalytic Oxidative Transformations Using Electrochemically Generated Hypervalent Iodine Species.

Abstract

A simple catalytic electrosynthetic protocol for oxidative transformations mediated by hypervalent iodine reagents has been developed. In this protocol, electricity drives the iodine(I)/iodine(III) catalytic cycle enabling catalysis with in situ generated hypervalent iodine species, thereby eliminating chemical oxidants and the inevitable chemical waste associated with their mode of action. In addition, no added electrolytic salts are needed in this process. The developed method has been validated using two different hypervalent iodine-mediated transformations: (i) the oxidative cyclization of N-allylic and N-homoallylic amides to the corresponding dihydrooxazole and dihydro-1,3-oxazine derivatives, respectively, and (ii) the α-tosyloxylation of ketones. Both reactions proceeded smoothly under the developed catalytic electrosynthetic conditions without reoptimization, featuring a wide substrate scope and excellent functional group tolerance. In addition, scale-up to gram-scale and catalyst recovery were easily achieved maintaining the high efficiency of the process.