694-53-1Relevant articles and documents
Reversible Silylene Insertion Reactions into Si?H and P?H σ-Bonds at Room Temperature
Rodriguez, Ricardo,Contie, Yohan,Nougué, Raphael,Baceiredo, Antoine,Saffon-Merceron, Nathalie,Sotiropoulos, Jean-Marc,Kato, Tsuyoshi
, p. 14355 - 14358 (2016)
Phosphine-stabilized silylenes react with silanes and a phosphine by silylene insertion into E?H σ-bonds (E=Si,P) at room temperature to give the corresponding silanes. Of special interest, the process occurs reversibly at room temperature. These results demonstrate that both the oxidative addition (typical reaction for transient silylenes) and the reductive elimination processes can proceed at the silicon center under mild reaction conditions. DFT calculations provide insight into the importance of the coordination of the silicon center to achieve the reductive elimination step.
Freeburger et al.
, p. 933,936 (1971)
CO Displacement in an Oxidative Addition of Primary Silanes to Rhodium(I)
Biswas, Abhranil,Ellern, Arkady,Sadow, Aaron D.
, (2019/03/11)
The rhodium dicarbonyl {PhB(Ox Me2)2ImMes}Rh(CO)2 (1) and primary silanes react by oxidative addition of a nonpolar Si-H bond and, uniquely, a thermal dissociation of CO. These reactions are reversible, and kinetic measurements model the approach to equilibrium. Thus, 1 and RSiH3 react by oxidative addition at room temperature in the dark, even in CO-Saturated solutions. The oxidative addition reaction is first-Order in both 1 and RSiH3, with rate constants for oxidative addition of PhSiH3 and PhSiD3 revealing kH/kD a 1. The reverse reaction, reductive elimination of Si-H from {PhB(Ox Me2)2ImMes}RhH(SiH2R)CO (2), is also first-Order in [2] and depends on [CO]. The equilibrium concentrations, determined over a 30 °C temperature range, provide ?"H° = a'5.5 ± 0.2 kcal/mol and ?"S° = a'16 ± 1 cal·mol-1K-1 (for 1 a?., 2). The rate laws and activation parameters for oxidative addition (?"Ha§§ = 11 ± 1 kcal·mol-1 and ?"Sa§§ = a'26 ± 3 cal·mol-1·K-1) and reductive elimination (?"Ha§§ = 17 ± 1 kcal·mol-1 and ?"Sa§§ = a'10 ± 3 cal·mol-1K-1), particularly the negative activation entropy for both forward and reverse reactions, suggest the transition state of the rate-Determining step contains {PhB(Ox Me2)2ImMes}Rh(CO)2 and RSiH3. Comparison of a series of primary silanes reveals that oxidative addition of arylsilanes is ca. 5× faster than alkylsilanes, whereas reductive elimination of Rh-Si/Rh-H from alkylsilyl and arylsilyl rhodium(III) occurs with similar rate constants. Thus, the equilibrium constant Ke for oxidative addition of arylsilanes is >1, whereas reductive elimination is favored for alkylsilanes.
Activations of all Bonds to Silicon (Si-H, Si-C) in a Silane with Extrusion of [CoSiCo] Silicide Cores
Handford, Rex C.,Smith, Patrick W.,Tilley, T. Don
supporting information, p. 8769 - 8772 (2019/06/07)
The [BP3iPr]Co(I) synthon Na(THF)6{[BP3iPr]CoI} (1, [BP3iPr] = κ3-PhB(CH2PiPr2)3-) reacts with PhSiH3 or SiH4 to form unusual {[BP2iPr](SiH2R)CoH2}=Si={H2Co[BP3iPr]} species (R = Ph, 2a; R = H, 2b; [BP2iPr] = κ2-PhB(CH2PiPr2)2) that result from activation of all Si - H and Si - C bonds in the starting silanes. Solution-spectroscopic data (multinuclear NMR, IR) for 2a,b, and the solid-state structure of 2a, indicate substantial Co=Si=Co multiple bonding and minimal interaction of the core Si atom with nearby hydride ligands. In the presence of 4-dimethylaminopyridine (DMAP), 1 reacts with PhSiH3 to give [BP3iPr](H)2CoSiHPh(DMAP) (3). Complexes 2a,b eliminate RSiH3 upon thermolysis in the presence of DMAP to generate {[BP2iPr]Co(NC5H3NMe2)}=Si={H2Co[BP3iPr]} (4).
