Reactions of [RuH(η3-C3H5)(CO)(PiPr3)2] and [Ru(η2-C2Ph2)(CO)(PiPr3)2] with terminal alkynes: synthesis and characterization of new five- and six-coordinate bis(alkynyl) and alkynyl(vinyl) derivatives of ruthenium(II)

The reaction of the complex [RuHCI(COXpipr3)2] with C3HsMgBr affords [RuH('03-C3HsXCOXpipr3)2] (2). This complex reacts with terminal alkynes. With CyC2H it yields [Ru(C2Cy)2(COXpipr3)2] (3), whereas with MeaSiC2H it gives a mixture of [Ru(C2SiMe3)2(CO)(pipr3)2] (4) and [Ru(C2SiMe 3) {(E)-CH=CHSiMe3}(CO)(pipr3)2](5). 4 was obtained as a spectroscopically pure oil by reaction of [RuH(*/E-H2BH2)(CO)(PtPr3)2] (15) with Me3SiCEH. 2 also reacts with PhCzPh giving [Ru(r/2-C2PhEXCOXPIPr3)2] (6), which with RCEH then yields [Ru(C2R){(E)-CH=CHR}(CO)(P*Pr3)2] (R = Cy (11), or -CO2CH 3 (12)). Under CO, 3 and 4 give [Ru(CER)E(CO)2(Pipr3)E](R = Cy (7) or (Me3Si (8)), but 5, 11 and 12 afford [Ru(CxR){(E)-CH=CHR}(CO)2(pipr3)2] (R = Me3Si (9), Cy (13), or -COzCH 3 (14)). 15 catalyzes the cyclotrimerization of methyl propiolate to give a mixture of 1,3,5-C6H3(COzCH3) 3 and 1,2,4-C6H3(COECH3) 3 in a 2:1 molar ratioWe thank the DGICYT (Project PB-92-0092, Programa de Promocion General del Conocimiento) and the E.U. (European Union) (Project: Selective Processes and Catalysis Involving Small Molecules) for financial support.Peer reviewe