Combined Photoredox and Carbene Catalysis for the Synthesis of γ-Aryloxy Ketones

N-heterocyclic carbenes (NHCs) have emerged as catalysts for the construction of C-C bonds in the synthesis of substituted ketones under single-electron processes. Despite these recent reports, there still remains a need to increase the utility and practicality of these reactions by exploring new radical coupling partners. Herein, we report the synthesis of gamma-aryloxyketones via combined NHC/photoredox catalysis. In this reaction, an alpha-aryloxymethyl radical is generated via oxidation of an aryloxymethyl potassium trifluoroborate salt, which is then added into styrene derivatives to provide a stabilized benzylic radical. Subsequent radical-radical coupling reaction with an azolium radical affords the gamma-aryloxy ketone products.

Automated summary

The research presents a method for synthesizing gamma-aryloxyketones via combined NHC/photoredox catalysis, where an α-aryloxymethyl radical is coupled with styrene derivatives and then with an azolium radical to produce the desired products.