Enantioconvergent Cobalt‐Catalyzed Hydroalkylation for the Construction of Fluoro‐, Chloro‐, and Trifluoromethyl Stereogenic Centers

Organic compounds containing a chiral, halogenated aliphatic carbon center are useful in medicinal chemistry, but their enantioselective synthesis remains difficult. Here we develop a general approach to access these compounds through cobalt‐catalyzed hydroalkylation of allenes and alkenes with dihaloamides. The reactions of allenes and terminal alkenes lead to alkylation only at the terminal position. In contrast, the reactions of internal alkenes occur via chain‐walking and alkylation at the terminal position. These reactions operate by enantioconvergent transformation of racemic secondary alkyl halides to give enantio‐enriched products. The method exhibits broad scope and high chemo, regio, and enantioselectivity. The synthetic utility of the method is demonstrated by further transformations of the products as well as the application in late‐stage functionalization of complex substrates.