Copper‐Catalyzed Enantioconvergent Cross‐Coupling of Racemic Alkyl Bromides with Azole C(sp 2 )−H Bonds

The development of enantioconvergent cross‐coupling of racemic alkyl halides directly with heteroarene C(sp 2 )−H bonds has been impeded by the use of a base at elevated temperature that leads to racemization. We herein report a copper(I)/cinchona‐alkaloid‐derived N , N , P ‐ligand catalytic system that enables oxidative addition with racemic alkyl bromides under mild conditions. Thus, coupling with azole C(sp 2 )−H bonds has been achieved in high enantioselectivity, affording a number of potentially useful α‐chiral alkylated azoles, such as 1,3,4‐oxadiazoles, oxazoles, and benzo[ d ]oxazoles as well as 1,3,4‐triazoles, for drug discovery. Mechanistic experiments indicated facile deprotonation of an azole C(sp 2 )−H bond and the involvement of alkyl radical species under the reaction conditions.