Phosphenium-Komplexe, 43 [1]. Ringöffnungsreaktionen der dreigliedrigen Phosphametallacyclen {PR2 = P(o-Tol)2, P(Ph)(o-Tol), P(Mes)[C(S)N(H)Et], P(/-Bu)[C(O)N(H)Et} / Phosphenium Complexes, 43 [1]. Ring-Opening Reactions of the Three-Membered Phosphametallacycles {PR1 = P(o-Tol)2, P(Ph)(oTol), P(Mes)[C(S)N(H)Et], P(r-Bu)[C(0)N(H)Et}

The three-membered phosphametallacycles [R = o-Tol (3a), R = Ph(3b)] react with the tertiary phosphanes Me P (4a), Me PhP (4b) or MePh P (4c) with ring opening and deselenation to the metallo-phosphanes fran.s-Cp(OC) (R P)WP(o-Tol)(R) (5a-d). Analogous reactions of the P-thioformamido- and formamido-substituted metallacycles [R = Mes, X = S (6a); R = t-Bu, X = O (6b)] with Me P (4a) yield in the case of 6a the tungsten-phosphane Cp(OC) (Me P)W-P(Mes)[C(S)N(H)Et] (7), while 6b affords the tungsten-selenophosphorane Cp(OC) (Me P)W-P(Se)(f-Bu)[C(0)N(H)Et] (8 ). Treatment of 7 with hydrogen chloride affords {Cp(OC) (Me P)W-P(H)(Mes)[C(S)N(H)Et] }C1 (9). With methyliodide, 8 is transformed into {Cp(OC) (Me P)W-P(SeMe)(t-Bu)[C(O)N(H)Et]}I (10)