INSERTION OF ETHYNE INTO THE RU-SI BONDS OF COORDINATIVELY UNSATURATED RUTHENIUM SILYL COMPLEXES, X-RAY CRYSTAL-STRUCTURES OF RU(CH=CHSIME(2)OET)CL(CO)(2)(PPH(3))(2) AND RU(CH=CHSIME(2)OH)(CN-P-TOLYL)(CO)(PPH(3))(2)]CLO4

The five-coordinate silyl complexes Ru(SiR(3))Cl(CO)(PPh(3))(2)(R(3) = Me(3) (1a), Et(3) (1b), Ph(3) (1c), Me(2)Cl (If)) are conveniently pr epared through reaction of Ru(Ph)Cl(CO)(PPh(3))(2) with the appropriat e silane, HSiR(3). Reaction of the Si-Cl bond in 1f with ethanol or hy droxide gives the corresponding ethoxysilyl or hydroxysilyl products R u(SiMe(2)X)Cl(CO)(PPh(3))(2) (X = OEt (1d), OH (1e)). Ethyne readily i nserts into the Ru-Si bond of 1a-d, and the corresponding five-coordin ate, silylalkenyl complexes Ru(CH=CHSiR(3))Cl(CO)(PPh(3))(2) (R(3) = M e(3) (2a), Et(3) (2b), Ph(3) (2c), Me(2)OEt (2d)) can be isolated in g ood yield. The complexes Ru(CH=CHSiR(3))Cl(Co)(2)(PPh(3))(2) (SiR(3) = SiMe(3) (3a); SiEt(3) (3b), SiMe(2)OEt (3d)) result from carbonylatio n of 2a,b,d, An X-ray crystal structure determination of Ru(CH=CHSiMe( 2)OEt)Cl(CO)(2)(PPh(3))(2) (3d) has been obtained. Reaction of Ru(CH=C HSiMe(3))Cl(CO)(PPh(3))(2) (2a) with CN-p-tolyl or sodium acetate give s Ru(CH=CHSiMe(3))Cl(CO)(CN-p-tolyl)(PPh(3))(2) (4a) or Ru(CH=CHSiMe(3 ))(eta(2)-O2CCH3)(CO)(PPh(3))(2) (5a), respectively. Insertion of ethy ne into the Ru-Si bond of 1e results in the formation of the metallacy clic ring-containing complex, Ru(CH=CHSiMe(3)OH)Cl(CO)(PPh(3))(2) (6e) , in which the hydroxysilyl oxygen atom is coordinated to ruthenium. R eaction of 6e with AgClO4 gives [Ru(CH=CHSiMe(2)OH)(CO)(NCMe)(PPh(3))( 2)]ClO4 (7e) and substitution of the labile acetonitrile in this compo und with CO or CN-p-tolyl generates [Ru(CH=CHSiMe(2)OH)(CO)(2)(PPh(3)) (2)]ClO4 (8e) or Ru(CH=CHSiMe(2)OH)(Co)(CN-p-tolyl)(PPh(3))(2)]ClO4 (9 e), respectively, The crystal structure of 9e has been determined, Dep rotonation of 8e or 9e with KOH gives the neutral complexes Ru(CH=CHSi Me(2)O)(CO)(2)(PPh(3))(2) (10e) or Ru(CH=CHSiMe(2)O)(CO)(CN-p-tolyl)(P Ph(3))(2) (11e), respectively. Complex 1b has been shown to catalyze t he hydrosilylation of both ethyne and phenylethyne by HSiEt(3).