Conjugate Boration of β,β-Disubstituted Unsaturated Esters: Asymmetric Synthesis of Functionalized Chiral Tertiary Organoboronic Esters

Challenging tertiary organoboronic esters containing a β‐ester group were prepared enantioselectively via the asymmetric conjugate boration of β,β‐disubstituted α,β‐unsaturated esters with a copper–phosphine catalyst (see scheme). The functionalized organoboron derivatives can be utilized as a carbon nucleophile to form all‐carbon quaternary centers.