Direct Stereoconvergent Allylation of Chiral Alkylcopper Nucleophiles with Racemic Allylic Phosphates

Copper‐catalyzed stereoconvergent allylation of chiral sp3‐hybridized carbon nucleophiles with a racemic mixture of acyclic secondary allylic phosphates is reported. In the presence of a copper‐catalyst complexed with chiral BenzP* ligand, tandem coupling reaction of vinyl arenes, bis(pinacolato)diboron, and racemic allylic phosphates provided β‐chiral alkylboronates possessing (E)‐alkenyl moiety through a direct stereoconvergent allylic coupling with concomitant generation of a C(sp3)‐stereogenic center. A range of vinyl (hetero)arenes and secondary allylic phosphates bearing 1°, 2°, 3° alkyl and phenyl α‐substituents were suitable for the reaction, forming products with high enantioselectivities up to 95 % ee. Density functional theory calculations were conducted in detail to elucidate the origin of the observed regioselectivity of borylcupration and stereoconvergent (E)‐olefin formation from racemic allylic phosphates. Direct stereoconvergent coupling of chiral alkylcopper species with racemic allylic phosphates was developed. Mechanistic studies and DFT calculations explain the origin of direct stereoconvergence in the tandem coupling process.