Catalytic asymmetric allylation of aldehydes with alkenes through allylic C(sp3)-H functionalization mediated by organophotoredox and chiral chromium hybrid catalysis.

Affiliation

Graduate School of Pharmaceutical Sciences , The University of Tokyo , 7-3-1 Bunkyo-ku , Tokyo 113-0033 , Japan . Email: [Email] ; Email: [Email]

Abstract

We describe a hybrid system that realizes cooperativity between an organophotoredox acridinium catalyst and a chiral chromium complex catalyst, thereby enabling unprecedented exploitation of unactivated hydrocarbon alkenes as precursors to chiral allylchromium nucleophiles for asymmetric allylation of aldehydes. The reaction proceeds under visible light irradiation at room temperature, affording the corresponding homoallylic alcohols with a diastereomeric ratio >20/1 and up to 99% ee. The addition of Mg(ClO4)2 markedly enhanced both the reactivity and enantioselectivity.