17336-24-2Relevant academic research and scientific papers
Toward selective functionalisation of oligosilanes: Borane-catalysed dehydrogenative coupling of silanes with thiols
Harrison, Daniel J.,Edwards, David R.,McDonald, Robert,Rosenberg, Lisa
, p. 3401 - 3411 (2008/12/20)
Among established methods for transforming Si-H bonds, carbonyl hydrosilylation and heterodehydrogenative coupling with alcohols catalysed by B(C6F5)3 are shown to provide exceptionally clean routes to the derivatisation of tetra-substituted disilanes such as [Ph2SiH]2, giving no products resulting from Si-Si bond cleavage. Even higher activity is observed for the borane-catalysed dehydrogenative coupling of silanes with alkyl- and arylthiols, the first examples of such Si-S bond formation in the absence of a transition metal catalyst. Clean, quantitative syntheses of a range of thiosilanes are reported, and the lability of the Si-S linkage toward subsequent alcoholysis is investigated. The crystal structure of 2,3-disila-2,2,3,3-tetramethyl-1,4- benzodioxane is presented.
A study of the silanolysis of triphenylsilane and p-methoxyphenolcatalysed by (PMe3)4RuH2 and the stoichiometric reactions of (PMe3)4Ru(H)(OC6H4-p-X) (X = Me, OMe) with Ph3SiH
Burn, Melinda J.,Bergman, Robert G.
, p. 43 - 54 (2007/10/02)
The ruthenium dihydride cis-(PMe3)4Ru(H)2 (1) catalytically converts PH3SiH and HOC6H4-p-OMe to the alcoholysis products Ph3SiOC6H4-p-OMe and H2.This reaction was studied kinetically and the rate was found to be first-order in , first-order in , and independent of .The stoichiometric reactions of cis-(PMe3)4Ru(H)(OC6H4-p-X) (X = Me, 2; OMe, 3) with Ph3SiH were also studied in the presence of varying amounts of free para-substituted phenol.In the absence of the free phenol, compounds 2 and 3 reacted with Ph3SiH to give Ph3SiOC6H4-p-X and a compound we believe to be (PMe3)3Ru(H)3(SiPh3) (4).In the presence of large amounts of phenol (> equiv.), (PMe3)4Ru(H)2 (1) was formed.However, at intermediate concentrations of free phenol, compounds 2 and 3 exhibited divergent behavior.Complex 2 gave dihydride 1 in a reaction whose rate was found to be first-order in the concentration of the starting aryloxy hydride 2, first-order in phenol and independent of .In contrast, complex 3 reacted with less than 0.5 equiv. of p-methoxyphenol to form 1, but when approximately 1 equiv. of p-methoxyphenol was added to the solution of 3 and Ph3SiH a mixture of trihydride 4 and dihydride 1 were formed.The mechanisms of these complicated transformations, and their potential relationship to the dihydride-catalyzed silanolysis reaction, are discussed. Key words: Silicon; Ruthenium; Silanolysis; Silane; Phenol
