DIHYDRIDOTETRAKIS(TRIPHENYLPHOSPHINE)RUTHENIUM(II), A CATALYST FOR ISOMERIZATION, HYDROGENATION AND H-D EXCHANGE-REACTIONS OF ALKENES

Dihydridotetrakis(triphenylphosphine)ruthenium(II), RuH2(PPh3)4, 1, serves as an appropriate model for studying the mechanisms of various catalytic reactions of olefins. 31P{;1H} and 1H-.n.m.r study of 1 in non-polar solvents revealed the octahedral cis-dihydrido configuration. A basic solvent molecule such as phyridine, N,N-dimethylformamide, as well as carbon monoxide, replaces one of the four PPh3 ligands in 1 and occupies a trans position to one of the mutually cis hydrido ligands, the fact suggesting a similar mode of olefin coordination in the actual catalytic reactions. On the basis of studies on catalytic isomerization of 1-butene, HD exchange reactions of ethylene, and hydrogenation of 1-hexene by 1, a mechanism involving olefin coordination to a partly dissociated species of 1, followed by the olefin insertion into one of the Rubonds, has been proposed. © 1979.