An Effective Strategy for the Preparation of α,β-Unsaturated Hydrazones and Pyrazole Derivatives. Synthetic Applications of β-Functionalized Phosphorus Compounds.

Article abstract of DOI:10.1016/S0040-4020(01)89404-7

β-Enehydrazino phosphonium salts 3 as well as β-hydrazono phosphine oxides 6 and phosphonates 7 are obtained from hydrazines, propargylphosphonium salts 2 and phosphorylated allenes 4 and 5. β-Functionalized compounds 3, 6 and 7 are used for the synthesis of α,β-unsaturated hydrazones 1, pyrazoline 14 and pyrazole derivative 15.