Cobalt‐Catalyzed Regiodivergent and Enantioselective Intermolecular Coupling of 1,1‐Disubstituted Allenes and Aldehydes

Catalytic enantioselective coupling of 1,1-disubstituted allenes and aldehydes through regiodivergent oxidative cyclization followed by stereoselective protonation or reductive elimination promoted by chiral phosphine–Co complexes is presented. Such processes represent unprecedented and unique reaction pathways for Co catalysis that enable catalytic enantioselective generation of metallacycles with divergent regioselectivity accurately controlled by chiral ligands, affording a wide range of allylic alcohols and homoallylic alcohols that are otherwise difficult to access without the need of pre-formation of stoichiometric amounts of alkenyl­– and allyl–metal reagents in up to 92% yield, >98:2 regioselectivity, >98:2 dr and >99.5:0.5 er.