Synthesis and Characterization of Some 2H-1,4,2-Diazaphosphole-, 2H-1,3,2-Diazaphosphole- and 2H-1,2-Diazaphosphole-P-sulfide Derivatives

Partial decomplexation of 2H-1,4,2-diazaphosphole and 2H-1,2-azaphosphole complexes is observed upon prolonged heating in benzonitrile; the liberated heterocycles were detected spectroscopically, but could not be isolated. The first 2H-1,3,2-diazaphosphole derivative, formed by thermal decomplexation using o-xylene and 1,2-bis(diphenylphosphino)ethane, was isolated and characterized. In all three cases, the corresponding heterocyclic P(V)-sulfides were obtained by oxidative decomplexation using elemental sulfur. All products were characterized by NMR and MS spectroscopy and two, additionally, by X-ray diffraction.