Main Text: Organic compounds containing P-stereogenic centers constitute important classes of pharmaceuticals, agrochemicals, and ligands for transition metal complexes (Fig. ) . The absolute stereochemistry at phosphorus often underpins the function of these compounds, ranging from their biological activities to their roles in asymmetric synthesis . Given the absence of a P-stereogenic chiral pool available from Nature (2), chemists' access to P-stereogenic compounds in enantioenriched form necessarily relies on the development of asymmetric synthetic methods . Well-established asymmetric syntheses of P-stereogenic compounds rely on covalently attached C-stereogenic chiral auxiliaries to achieve diastereocontrol over transformations at the phosphorus center (Fig. , left) . Asymmetric catalytic approaches have been identified that rely on coupling at the phosphorus center, substitution at phosphorus, or desymmetrization of substituents (1, 7) (Fig. , right). In particular, recent organocatalytic approaches have established the viability of substitution at phosphorus as a successful principle for catalytic We noted, however, that no approach to date has drawn from the diverse manifold of powerful transformations involving phosphonium dealkylation events such as the Michaelis-Arbuzov, Appel, Staudinger, and Pudovik reactions , reactions for which there is over 125 years of demonstrated synthetic utility. Inspired by the capacity of chiral dual-hydrogen-bonddonors (HBDs) to bind anions to generate chiral ion-pair intermediates , we hypothesized that a suitable HBD catalyst might prove effective in binding a phosphonium ion pair and reorganizing it into a configuration that is favorable for enantioselective dealkylation (Fig. ). Because catalytic enantiocontrol over phosphonium ions has, to our knowledge, yet to be discovered in synthetic or biological systems, we posited that developing this approach might ultimately unlock catalytic asymmetric variants of the manifold of important phosphoniummediated reactions (Fig. ).