Preparation of Optically Pure Tertiary Phosphine Oxides via the Addition of <i>P</i>‑Stereogenic Secondary Phosphine Oxide to Activated Alkenes

Functionalized <i>P,C</i>-stereogenic tertiary phosphine oxides were prepared by the addition of (<i>R</i>_P)-menthyl phenylphosphine oxide to activated olefins, in high dr_P and dr_C, and were isolated in excellent yields. The reaction was readily catalyzed by Ca­(OH)₂ or occurred with gentle heating. A wide range of substrates, including vinyl ketones, esters, nitriles, and nitro alkenes, can be used in the reaction