The beta-diketiminato complex [{HC(C(Me)(2)N-2,6-(Pr2C6H3)-Pr-i)(2)}Ca{N(SiMe3)(2)}(THF)] effects intermolecular hydrophosphination of a range of alkenes and alkynes. In behavior reminiscent of lanthanocene(III) catalysis, a more electrophilic alkene is polymerized to phosphine-terminated macromolecules.