Hiromichi Kono

Phosphine complexes of silylruthenium hydrides. Interaction of silicon hydride with RuH2(PPh3)4, RuCl2(PPh3)3, and RuHCl(PPh3)3

Abstract The reaction of RuH2(PPh3)4 with a variety of organosilicon hydrides, R3SiH, gave the complexes RuH3(SiR3)(PPh3)3 where R3Si  Et3Si, EtMe2Si, PhMe2Si, Ph3Si, Ph(MeO)2Si, (EtO)3Si, Et2HSi, PhMeHSi, Ph2HSi, cyclo-C6H11H2Si, and PhH2Si. Without solvent RuCl2(PPh3)3 and RuHCl(PPh3)3 · C6H6 reacted with R3SiH, where R3Si  Cl3Si, Cl2MeSi, ClMe2Si, Ph(MeO)2Si, (EtO)3Si, and (MeO)3Si, to give RuH(SiR3)PPh3)2; in benzene solution, however, hydrides such as ClMe2SiH, Ph(MeO)2SiH, Et2SiH2, Ph2SiH2, andcyclo-C6H11SiH3, afforded RuH(SiR3)(PPh3)3. RuCl2(PPh3)3 was reduced by Et3SiH, PhMe2SiH, and EtMe2SiH in organic solvents to give RuH(Cl(PPh3)3 · solvent. These silylruthenium hydride complexes were characterized by IR, NMR, and elemental analyses. The reactions of some silylruthenium hydride complexes were also investigated.

Hydrogen—chloride exchange between organosilicon hydrides and polychloroalkanes catalyzed by ruthenium(II)-phosphine complexes

Abstract Carbon tetrachloride, 1,1,1-trichloroethane, and 1,1,1,3-tetrachloroalkanes were selectively reduced by silicon hydrides to give chloroform, 1,1-dichloroethane, and 1,1,3-trichloroalkanes, respectively, in high yields in the presence of catalytic amounts of phosphine complexes of ruthenium(II) such as RuCl 2 (PPh 3 ) 3 , RuHCl(PPh 3 ) 3 , RuH 2 (PPH 3 ) 4 , and RuH(SiMe 2 Cl)(PPh 3 ) 3 . Reactivities of a wide variety of silicon hydrides towards the dechlorination also were estimated. The catalytic cycle can be explained in terms of successive oxidative addition, reductive elimination, and hydrogen—halogen exchange on the ruthenium—phosphine complex.