Access toP-chiralsec- andtert-phosphine oxides enabled by Le-Phos-catalyzed asymmetric kinetic resolution

The synthesis ofP-stereogenic building blocks is extremely difficult. Herein we report an efficient kinetic resolution of secondary phosphine oxidesviaa Le-Phos-catalyzed asymmetric allylation reaction with Morita-Baylis-Hillman carbonates. This method provides facile access to enantioenriched secondary and tertiaryP-chiral phosphine oxides with broad substrate scope, both of which could serve asP-stereogenic synthons, and can be rapidly incorporated into a given scaffold bearing aP-stereocenter. The highly desirable late stage modifications demonstrate the practicability of our method and can be a critical contribution to obtaining optimalP-chiral catalysts and ligands.