1003947-41-8Relevant academic research and scientific papers
Silylene extrusion from organosilanes via double geminal Si-H bond activation by a Cp*Ru(κ2-P,N)+ complex: Observation of a key stoichiometric step in the Glaser-Tilley alkene hydrosilylation mechanism
Rankin, Matthew A.,MacLean, Darren F.,Schatte, Gabriele,McDonald, Robert,Stradiotto, Mark
, p. 15855 - 15864 (2007)
Treatment of Cp*RuCl(κ2-P,N-2b) (2b = 2-NMe 2-3-PiPr2-indene) with TISO3CF 3 produced the cyclometalated complex [4]-SO 3CF3- in 94% isolated yield. Exposure of [4]+X- (X = B(C6F5)4 or SO3CF3) to Ph2SiH2 (10 equiv) or PhSiH3 afforded the corresponding [Cp*(μ-P,N-2b)(H) 2Ru=SiRPh]+X- complexes, [5]+X - (R = Ph; X = B(C6F5)4, 82%; X = SO3CF3, 39%) and [6]+X- (R = H; X = B(C6F5)4, 94%; X = SO3CF 3, 95%). Notably, these transformations represent the first documented examples of Ru-mediated silylene extrusion via double geminal Si-H bond activation of an organosilane - a key step in the recently proposed Glaser - Tilley (G-T) alkene hydrosilylation mechanism. Treatment of [5] +B(C6F5)4- with KN-(SiMe3)2 or [6]+SO3CF 3- with NaN(SiMe3)2 afforded the corresponding zwitterionic Cp*(μ-2-NMe2-3-P iPr2-indenide)(H)2Ru=SiRPh complex in 69% (R = Ph, 7) or 86% (R = H, 8) isolated yield. Both [6]+X- and 8 proved unreactive toward 1 -hexene and styrene and provided negligible catalytic turnover in the attempted metal-mediated hydrosilylation of these substrates with PhSiH3, thereby providing further empirical evidence for the required intermediacy of base-free Ru=Si species in the G-T mechanism. Isomerization of the P,N-indene ligand backbone in [6]+X_, giving rise to [Cp*(μ-1-PiPr2-2-NMe 2-indene)(H)2Ru=SiHPh]+X- ([9] +X-), was observed. In the case of [9]+SO 3CF3-, net intramolecular addition of the Ru=Si-H group across the styrene-like C=C unit within the ligand backbone to give 10 (96% isolated yield) was observed. Crystallographic characterization data are provided for [4]+X-, [5]+X -, [6]+X-, 8, and 10.
