The copper‐catalyzed reaction of α‐halo‐N‐tosylhydrazones with H‐phosphoryl compounds is reported to afford alkenylphosphoryl compounds in modest to good yields. The reaction may take place via a copper‐promoted Bamford‐Stevens‐type reaction of an α‐phosphorylated diazo intermediate. The diazo intermediate is trapped by an excess H‐phosphoryl compound to give α, N‐bisphosphoryl hydrazone in the absence of a copper catalyst.