MASKED IMINOPHOSPHIDE ANION - SYNTHESIS AND VERSATILE REACTIVITY

The unprecedented iminozirconiophosphorane 3, Me(2)P(ZrCp(2)Cl)=N-Ar ( Ar = 2,4,6-t-Bu(3)C(6)H(2)), a masked iminophosphide, has been prepare d by reacting chloroiminophosphane 2, Cl-P=N-Ar, with Cp(2)ZrMe(2). In sertion reactions into the zirconium-phosphorus bond take place when 3 is reacted with nitriles, paraformaldehyde, or carbon disulfide, givi ng rise to iminophosphoranes. Formal insertion into the nitrogen-zirco nium bond occurs when 3 is treated with isocyanides RNC (R = Me(3)SiCH (2), cyclohexyl), affording phosphanes. A single-crystal X-ray structu re of one of them has been determined. Addition of pyridine-HCL, methy l iodide, N-bromosuccinimide, or various chlorophosphanes to 3 leads t o iminophosphoranes via exchange reactions taking place directly on th e phosphorus center of 3. Addition of the Eschenmoser salt [H2C=NMe(2) ]Cl to 3 affords a mixture of iminophosphorane and phosphonium salt. 3 reacts with triflic acid or methyl trifluoromethanesulfonate, giving exclusively phosphonium salts. Reactions involving the thermodynamical ly stable form of 3, i.e. the phosphane 5, Me(2)P-N(ZrCp(2)Cl)(2,4,6-t -Bu(3)C(6)H(2)), occur when 3 is treated with the chloroiminophosphane 2 with formation of a phosphanyliminophosphane. Treatment of 3 with N iCl2 or PdCl2 gives rise to the complexes 28a (M = Ni) and 28b (M = Pd ), [Me(2)P-N(H)-2,4,6-t-Bu(3)C(6)H(2)](2)MCl(2).