Cobalt-Catalyzed Markovnikov Hydroarylcarbonylation of Unactivated Alkenes via Distal Aryl Migration

Hydrocarbonylation of alkenes with CO represents one of the most fundamental protocols for synthesis of carbonyl compounds from readily available feedstocks. However, the development of Markovnikov-selective hydroarylcarbonylation of unactivated alkenes to afford branched ketones remains a formidable challenge in both reactivity and selectivity control. Herein, we report a cobalt-catalyzed Markovnikov hydroarylcarbonylation of unactivated alkenes via distal aryl migration. The protocol exhibits broad substrate scope and wide functional group compatibility, enabling highly chemo- and regioselective synthesis of 1,4-diketones bearing α-tertiary and α-quaternary carbon centers in moderate to good yields. The synthetic utility of this method has been demonstrated through downstream transformations of the resulting products to diverse substituted heteroarenes and cyclopentenones. Preliminary mechanistic studies suggest the reaction proceeds through a CO-mediated hydrogen atom transfer (HAT) and an acyl radical species is generated to promote the distal aryl migration through a five-membered cyclic transition state.