Cobalt-Catalyzed Markovnikov Hydrofluorocarbonylation of Unactivated Alkenes

Acyl fluorides are highly versatile synthons in organic synthesis due to their distinctive balance of stability and reactivity. However, the synthesis of alkyl-substituted acyl fluorides from readily available feedstocks remains challenging. Herein, we report a cobalt-catalyzed Markovnikov hydrofluorocarbonylation of unactivated alkenes, enabling the highly chemo- and regioselective synthesis of branched alkyl-substituted acyl fluorides. The mild reaction conditions allow use of mono-, di-, and trisubstituted alkenes bearing a variety of functional groups. Cooperating with one-pot nucleophile addition and the downstream transformations of the resulting products, this method offers a complementary platform for the synthesis of diverse branched carbonyl compounds and their derivatives from alkenes. Preliminary mechanistic studies suggest that the reaction proceeds through a carbon monoxide (CO)-mediated hydrogen atom transfer (HAT) and radical-polar crossover (RPC) process, in which a highly electrophilic acyl cobalt(IV) complex is proposed as the key intermediate to promote nucleophilic fluorination.