An efficient method for the synthesis of C-phosphonoketenimines through palladium-catalyzed migratory insertion of isocyanides has been developed for the first time. This procedure tolerates wide functional groups and has a good atom economy. Further transformations of the products, which are useful building blocks for the β-aminophosphonates, β-aminovinylphosphonates, and C-phosphorylated tetrazoles, indicate potential synthetic utility.