Markovnikov Hydrocarboxylation Enabled by Reductive Cobalt Catalyzed Hydrogen-Atom-Transfer

Carbon dioxide is a promising feedstock for fine chemical synthesis, yet its inherent stability necessitates innovative catalytic strategies for its use as a reagent under mild conditions. A valuable transformation that can directly use CO2 is olefin hydrocarboxylation. While recent photocatalytic methods enable anti-Markovnikov selective hydrocarboxylation via CO2•− addition to alkenes, Markovnikov-selective approaches remain scarce and often rely on noble metals or stoichiometric organometallic reagents. Here, we present a radical-based Markovnikov hydrocarboxylation strategy leveraging metal-catalyzed hydrogen atom transfer (MHAT). Our approach employs a reductively generated Co(III)–H species to initiate HAT, and reductive radical-polar crossover of the carbon-centered radical that is formed to yield a carbanion which reacts with CO2. The successful implementation of this strategy represents a new dimension for MHAT catalysis, delivering a functional-group-tolerant hydrocarboxylation platform that provides complementary regioselectivity to existing photocatalytic approaches whilst avoiding precious metals and stoichiometric organometallics.