Activation of Water and of Dioxygen by a Bis(diphenylphosphinopropyl)silyl (biPSi) Complex of Ruthenium(II): Formation of Bis(diphenylphosphinopropyl)siloxo Cage Complexes. Concomitant Oxygen Atom Insertion into a Silicon−Carbon Bond

The coordinatively saturated hydrido complex RuH(biPSi)(CO) 2 ( 1 ), biPSi = −Si(Me)(CH 2 CH 2 CH 2 PPh 2 ) 2, reacts slowly with either water/piperidine or dioxygen to afford the novel “anchored” siloxo complexes ( 3, L = CO) and ( 6, L = CO), respectively, which undergo carbonyl displacement to yield analogues in which L = P(OMe) 3 that are crystalline ( 5 or 7, respectively) and for which anti stereochemistry (i.e., H at Ru vs Me or OMe at Si) has been identified by using X-ray crystallography (i.e., products 5-a, 7-a respectively). Complex 1 catalyzes autoxidation of cyclohexene (mainly to cyclohexenone, cyclohexenol:TTO ≈ 300, 4 h).