Synthesis and stereoselectivity of a new type of unsaturated phosphonates

(Z)-(1,2-Dichlorovinyl)diphenylphosphine oxide

The title compound, C₁₄H₁₁Cl₂OP, was synthesized by the reaction of diphenyl­phosphine oxide with 1,2-dichloro­ethyne under CuI catalysis. The reaction provided the Z isomer regioselectively. Two O—P—C bond angles [114.3 (1) and 112.5 (1)°] are significantly larger than the C—P—C [107.7 (1), 105.6 (1) and 106.6 (1)°] and another O—P—C angle [109.5 (1)°], indicating significant distortion of the tetra­hedral configuration of the P atom. In the crystal, mol­ecules are linked by weak inter­molecular C—H⋯O hydrogen bonds into centrosymmetric dimers, which are connected by further C—H⋯O inter­actions into chains along [101].