NHC-Catalyzed Synthesis of ?-Sulfonyl Ketones via Radical- Mediated Sulfonyl Methylation of Aldehydes

An N-heterocyclic carbene (NHC)-catalyzed facile assembly of alpha-sulfonyl ketones has been successfully developed through a radical-mediated sulfonyl methylation of readily available aldehydes. This protocol involves the effective single-electron transfer reduction of alpha-iodosulfones by NHC-bound Breslow intermediates, thus allowing a subsequent radical-radical coupling to afford the target compounds. Moreover, the catalytic system was found to be equally effective for difunctionalization of styrenes and 1,3-enynes via a three-component radical relay process.

Automated summary

A novel method for the facile assembly of alpha-sulfonyl ketones through N-heterocyclic carbene (NHC)-catalyzed radical-mediated sulfonyl methylation of aldehydes has been developed. The reaction involves single-electron transfer reduction of alpha-iodosulfones by NHC-bound Breslow intermediates, followed by radical-radical coupling to form the target compounds. Furthermore, the catalytic system is also effective for the difunctionalization of styrenes and 1,3-enynes via a three-component radical relay process.