REACTIVITY OF N PHENYL IMINOPHOSPHORANES TOWARDS OZONE: EVIDENCE OF TRIOXO AZAPHOSPHOLANE INTERMEDIATES

The ozonation of N-phenyl-iminophosphoranes R3P=NPh 1a-b leads, after the P-N bond breakage, to the corresponding phosphorus oxides 2a-b with the formation of complex adducts 3a-b which precipitate at room temperature. The stoichiometry and the reaction mechanism depend on the nature of substituents R linked to the phosphorus atom. For R=Ph we detected the phosphonium intermediate 5a, whereas for R=OEt the trioxoazaphospholanes 7b-9b were characterized by P-31 NMR.