53358-43-3

Upstream product

• 17909-51-2 (dimethyl(phenyl)silyl)(phenyl)methanone 
• 908093-98-1 diazodiphenylmethane 
• 766-77-8 Dimethylphenylsilane 
• 65-85-0 benzoic acid 

Relevant academic research and scientific papers

Chemoselective ruthenium-catalysed reduction of carboxylic acids

A very general and efficient catalytic protocol for the selective reduction of carboxylic acids to their corresponding alcohols under mild conditions is described. Various carboxylic acids, including benzoic acids, were reduced in good yields using the presented methodology. The ruthenium-catalysed method yields a highly chemoselective reduction permitting the reduction of a carboxylic acid functionality in the presence of numerous other potentially reducible moieties.

Rhodium carbene complexes as versatile catalyst precursors for Si-H bond activation

Rhodium(III) complexes comprising monoanionic C,C,C-tridentate dicarbene ligands activate Si-H bonds and catalyse the hydrolysis of hydrosilanes to form silanols and siloxanes with concomitant release of H2. In dry MeNO2, selective formation of siloxanes takes place, while changing conditions to wet THF produces silanols exclusively. Silyl ethers are formed when ROH is used as substrate, thus providing a mild route towards the protection of alcohols with H2 as the only by-product. With alkynes, comparably fast hydrosilylation takes place, while carbonyl groups are unaffected. Further expansion of the Si-H bond activation to dihydrosilanes afforded silicones and polysilyl ethers. Mechanistic investigations using deuterated silane revealed deuterium incorporation into the abnormal carbene ligand and thus suggests a ligand-assisted mechanism involving heterolytic Si-H bond cleavage. Ligand-assisted Si-H bond cleavage: Rhodium-catalysed Si-H bond activation provides a methodology for the silyl group to be transferred to oxygen centres, thus providing access to siloxanes and silanols (using H 2O), alkoxysilanes (using ROH) and to polysiloxanes, such as silicones, when using difunctional silanes. The process is pH neutral, avoids sensitive silylating agents and produces H2 as useful and exclusive side product. Copyright

Cationic silane δ-complexes of ruthenium with relevance to catalysis

Hydrosilylation of carbonyls catalyzed by 2 goes via intermediate formation of cationic silane σ-complexes 4 which undergo nucleophilic abstraction of the silylium cation studied by DFT calculations.

An efficient solvent-free route to silyl esters and silyl ethers

Dinuclear metal complexes, especially (p-cymene)ruthenium dichloride dimer {[RuCl2(p-cymene)]2}, have been found to exhibit high catalytic performance for the dehydrosilylation of various kinds of carboxylic acids and alcohols. The dehydrosilylation with [RuCl2(p-cymene)] 2 proceeded efficiently with only one equivalent of silane with respect to substrate (carboxylic acids or alcohols) under solvent-free conditions to give the corresponding silyl esters and ethers in excellent yields with a high turnover number (TON) and frequency (TOF). The 1H NMR spectrum of a toluene-d8 solution of [RuCl2(p-cymene)] 2 and a silane showed a signal assignable to the ruthenium hydride species. In contrast, no new signals were detected in the 1H NMR spectrum of a toluene-d8 solution of [RuCl2(p-cymene)] 2 and a carboxylic acid or an alcohol. There-fore, the ruthenium metal in [RuCl2(p-cymene)]2 activates a silane to afford the hydride intermediate, possibly a silylmetal hydride species. Then, the nucleophilic attack of a substrate (carboxylic acid or alcohol) to the hydride intermediate proceeds to give the corresponding silylated product. The present dehydrosilylation with an optically active silane proceeded exclusively under inversion of stereochemistry at the chiral silicon center, suggesting that the nucleophilic attack of a substrate to the hydride intermediate occurs from the backside of the ruthenium-silicon bond.

Dye-Sensitized Photooxidation of Silyl Diazo Compounds. Intramolecular Oxygen Transfer of Carbonyl Oxides

The dye-sensitized photooxidation of silyl diazo compounds produced the corresponding silyl ketones and silyl esters, and the latter may be formed by the rearrangement of silyl-substituted carbonyl oxides.The reactions of a carbonyl oxide with various silyl ketones were also studied.The dye-sensitized photooxidation of diphenyldiazomethane in the presence of silyl ketones gave silyl esters together with benzophenone by reactions of a carbonyl oxide with the silyl ketones accompanying 1,2-anionic rearrangement of the silyl group.