Copper-Catalyzed Aerobic Oxidation of Phenylboronic Acids to Aryl Radical: The Application in Synthesis of 2-Arylacetophenones

The oxidation of phenylboronic acids to generate aryl radicals provides an alternative strategy for valorizing this widely used reagent. Unlike conventional methodologies that require stoichiometric quantities of metal oxidants or peroxides, we herein describe a copper-catalyzed aerobic oxidation system for converting phenylboronic acids to aryl radicals, which undergo trapping by atropaldehyde acetal to afford high-value 2-arylacetophenones. This protocol not only represents an atom-economical manner to produce aryl radicals from boronic acids, but also furnishes an efficient route to synthesize heteroarene such as quinoline, indole, and quinoxaline via in situ transformation of the resulting products.