Search results for "Triethylsilane"
showing 5 items of 5 documents
Direct observation of a borane-silane complex involved in frustrated Lewis-pair-mediated hydrosilylations.
2014
Perfluorarylborane Lewis acids catalyse the addition of silicon-hydrogen bonds across C=C, C=N and C=O double bonds. This 'metal-free' hydrosilylation has been proposed to occur via borane activation of the silane Si-H bond, rather than through classical Lewis acid/base adducts with the substrate. However, the key borane/silane adduct had not been observed experimentally. Here it is shown that the strongly Lewis acidic, antiaromatic 1,2,3-tris(pentafluorophenyl)-4,5,6,7-tetrafluoro-1-boraindene forms an observable, isolable adduct with triethylsilane. The equilibrium for adduct formation was studied quantitatively through variable-temperature NMR spectroscopic investigations. The interactio…
Synthesis of Chiral Catalyst Modifiers by Hydrosilylation of Cinchonidine and Their Application in the Hydrogenation of 1-Phenylpropane-1,2-dione and…
2005
Four new chiral modifiers were synthesized in order to investigate the effect of distal modifier substitution in the hydrogenation of ethyl pyruvate and 1-phenylpropane-1,2-dione on a supported Pt/Al2O3 catalyst. The chiral modifiers were prepared in good to moderate overall yields by Pt-catalyzed hydrosilylation of 9-O-TMS-protected cinchonidine with triethylsilane, triphenylsilane, bis(dimethylsilyl)ethane and (+)-(R)-methyl(1-naphthyl)phenylsilane followed by cleavage of the silyl ether protective group. Comparison of the synthesized modifiers in enantioselective hydrogenation using cinchonidine as reference modifier is reported, as well as details on their synthesis and characterization…
Palladium on Charcoal as a Catalyst for Stoichiometric Chemo- and Stereoselective Hydrosilylations and Hydrogenations with Triethylsilane
2014
Stoichiometric quantities of triethylsilane in the presence of activated Pd/C as the catalyst can be used to effect chemo-, regio-, and stereoselective hydrosilylation and transfer hydrogenation reactions. α,β-Unsaturated aldehydes and ketones are selectively hydrosilylated to give the corresponding enol silanes or transfer hydrogenated to give the saturated carbonyl compounds in the presence of other reducible functional groups.
Pd/C-Catalyzed Hydrosilylation of Enals and Enones with Triethylsilane: Conformer Populations Control the Stereoselectivity
2016
The palladium-on-charcoal-catalyzed chemo-, regio-, and stereoselective 1,4-hydrosilylation and transfer hydrogenation reactions of α,β-unsaturated aldehydes and ketones with triethylsilane have been investigated with a combination of experimental and theoretical methods. The reaction mechanism has been studied experimentally by monitoring the reactions by 1H NMR from aliquots withdrawn from the stirred reaction mixtures, labeling experiments, and control experiments. Our density functional theory results indicate that both aforementioned reactions are initiated with a dissociative adsorption of the triethylsilane on the palladium catalyst. In the hydrosilylation reaction, the α,β-unsaturat…
Die alkoholyse des triethylsilans katalysiert von [(CH3)3P]2Ru(CO)2Cl2
1983
Abstract [(CH 3 ) 3 Pl 2 Ru(CO) 2 Cl 2 is an effective catalyst for the reaction of alcohols with triethylsilane. The rate of this reaction varies with the substituents in the hydroxy compound; it is fastest for short primary alcohols. Even in the presence of groups which can be hydrosilated (CC triple or double bonds, as well as ketones), a hydroxy group reacts preferably and completely with the silane. Kinetic experiments have been performed with the system Et 3 SiH/CH 3 CH(OH)COOEt/Ru complex.