Chiral phosphines, valuable ligands for metal-catalyzed asymmetric reactions, 1 are usually prepared either by resolution or by using a stoichiometric amount of a chiral auxiliary. 2 Surprisingly, metal-catalyzed asymmetric syntheses of these ligands are rare. 3 We report here that Pd-catalyzed asymmetric phosphination (crosscoupling of a secondary phosphine PH(R)(R′) with an aryl halide or triflate) 4 can be used to prepare a P-chirogenic phosphine with control of stereochemistry at phosphorus. Observations of potential intermediates in the catalytic cycle suggest that dynamic resolution of rapidly inverting phosphorus stereocenters is responsible for the enantiomeric excess (ee)