Asymmetric Construction of Tertiary/Secondary Carbon–Phosphorus Bonds via Bifunctional Phosphonium Salt Catalyzed 1,6-Addition

The carbon–phosphorus bond engenders distinctive physicochemical properties and has significant applications in chemical science. Herein, we disclose an efficient and practical catalytic protocol for the asymmetric synthesis of remote C–P bonds by a synergistic strategy of stabilizing the P-nucleophile by a chiral phosphonium salt catalyst together with activating the extended π-system by a side group, thus leading to a cascaded 1,6-addition/aromatization reaction. This protocol provides straightforward and expedient access to an array of both tertiary and secondary C–P stereocentralized molecules in high yield with exciting enantioselectivities (up to >99% ee). Moreover, systematic mechanistic studies, including thorough DFT calculations and control experiments, provide insights into the mechanism.