Efficient hydrosilylation of carbonyl compounds by 1,1,3,3-tetramethyldisiloxane catalyzed by Au/TiO2

The chemistry of tetramethyldisiloxane (TMDS) is largely composed of the reduction of functional groups with increasing applications for carboncarbon bond formation. This reagent can be a safe alternative to H 2 , LiAlH 4 , and other reactive reagents. Notable are the amide conversion to amines and aldehydes, nitro group reductions, nitrile reductions, hydrogenolysis of arylchlorine bonds, reductive formation of sulfides, reductive etherification, reductive opening of ketals, reductive demethoxylation, and formation of nitriles with homologation. Selectivity can be carried out by the choice of catalysts. This review of recent chemistry will focus on synthetically applied reactions of the recent past. Displayed reactions are chosen to be representative of the referenced work, but are also chosen to illustrate a new viewpoint. Finally, where applicable, the results of competing hydrosilanes are presented to compare to the results obtained with TMDS.

show abstract

“…120 Reduction of aldehydes by TMDS was reported above, but this variation reacts both classes of carbonyls (Eqs. 146 and 147).…”

Section: Miscellaneous Tmds Reductionsmentioning

confidence: 92%

Tetramethyldisiloxane: A Practical Organosilane Reducing Agent

Pesti

Larson

2016

Org. Process Res. Dev.

103

View full text Add to dashboard Cite

show abstract

“…The limited studies regarding the nano Au-catalyzed hydrosilylation of carbonyl compounds encouraged our group to examine the scope and limitations using commercially available Au/TiO 2 (0.5 mol%) as the catalyst. 40 However, the results were not overly impressive. Briefly, a typical aromatic aldehyde, such as tolualdehyde (27), requires 2 equivalents of a common hydrosilane such as Et 3 SiH, and heating at 70 °C for 12 hours to obtain the hydrosilylation product in a good yield (72%).…”

Section: Scheme 14 Hydrosilylation Of Carbonyl Compoundsmentioning

confidence: 96%

“…41 It was discovered that the reduction of aldehydes or ketones with TMDS occurs up to 50 times faster compared to typical hydrosilanes such as Et 3 SiH or PhMe 2 SiH, and can take place at room temperature in much shorter reaction times, or at 65 °C within a few minutes (Scheme 15). 40 As a typical example, the hydrosilylation of p-cumylaldehyde with TMDS occurs with a TOF = 3000 h -1 . The origins of this significant enhancement of reactivity are unclear and cannot be attributed to steric effects as the relative reaction rate between TMDS and structurally similar 1,1,1,3,3-pentamethyldisiloxane (PMDS) is k TMDS /k PMDS ~ 20.…”

Section: Scheme 14 Hydrosilylation Of Carbonyl Compoundsmentioning

confidence: 99%

Nanogold(0)-Catalyzed Addition of Heteroelement σ Linkages to Functional Groups

Stratakis

Lykakis

2019

Synthesis

Self Cite

View full text Add to dashboard Cite

In recent years, supported Au nanoparticles and nanoporous Au materials have shown remarkable catalytic activity in the activation of σ heteroelement linkages such as, Si–H, Si–Si, B–B and B–Si, and their subsequent addition to functional groups, primarily π bonds. In this review article we discuss the reaction modes known to date, and attempt to discuss the mechanistic clues of these transformations which are rather unexpected in terms of conventional transition-metal catalysis concepts, given that the catalytic sites are metallic Au(0).1 Introduction2 Activation of Hydrosilanes2.1 Reactions of Hydrosilanes with Alkynes2.1.1 Hydrosilylation2.1.2 Dehydrogenative Coupling2.2 Reactions of Hydrosilanes with Allenes2.3 Reactions of Hydrosilanes with Carbonyl Compounds and Imines2.4 Reactions of Hydrosilanes with α-Diazo Carbonyl Compounds2.5 Miscellaneous Transformations from the Nano Au-Catalyzed Activation of Hydrosilanes3 Activation of Disilanes3.1 Disilylation of Alkynes3.2 Reactions of 1,1,2,2-Tetramethyldisilane with Alkynes4 Activation of Diboranes4.1 Diborylation of Alkenes4.2 Diborylation of Alkynes4.3 Diborylation of Allenes4.4 Diborylation of Methylenecyclopropanes5 Activation of Silylboranes5.1 Silaboration of Alkynes5.2 Silaboration of Allenes5.3 Silaboration of Unactivated Epoxides and Oxetanes5.4 Reactions of Silylboranes with Aromatic Carbonyl Compounds6 Conclusions and Future Perspectives

show abstract

“…For hydrosilane, polymethylhydrosiloxane (PMHS) as the cheapest hydrosilane agent and the by-product of the silicon industry is an ideal H-donor for the hydrogenation of FUR to FFA [8,52,53]. At the same time, PMHS is a green agent as it is nontoxic and having great chemical stability for water and atmosphere [54,55].…”

Section: Introductionmentioning

confidence: 99%

Highly Selective Reduction of Bio-Based Furfural to Furfuryl Alcohol Catalyzed by Supported KF with Polymethylhydrosiloxane (PMHS)

et al. 2020

Journal of Chemistry

View full text Add to dashboard Cite

Hydrogenation of bio-based furfural (FUR) to furfuryl alcohol (FFA) is tremendously expanding the application of biomass in many industries such as resins, biofuels, and pharmaceuticals. However, mass manufacture of FFA from FUR is restrained by strict requirements of reaction conditions and expensive catalysts. In this work, an economical and benign catalytic system, containing an easily prepared and reusable catalyst 5 wt.% KF/ZrO2 and a low-cost hydrogen source polymethylhydrosiloxane (PMHS), was developed to be efficient for the hydrogenation of FUR to high-value FFA under mild conditions. The catalyst reactivity was found to be remarkably influenced by the support acid-base properties and KF loading doge. In the presence of 5 wt.% KF/ZrO2, a high FFA yield of 97% and FUR conversion of 99% could be obtained at 25°C in just 0.5 h, which was superior to those attained with other tested catalysts. The KF/ZrO2 catalyst could be recycled at least five times, with the FFA yield slightly decreasing from 97% to 71%. The spare decrease in FFA yield is possibly attributed to the catalyst pore blocking, as clarified by SEM, BET, XPS, and ICP-MS measurements of the fresh and reused catalysts.

show abstract

Efficient hydrosilylation of carbonyl compounds by 1,1,3,3-tetramethyldisiloxane catalyzed by Au/TiO2

Cited by 21 publications

References 51 publications

Tetramethyldisiloxane: A Practical Organosilane Reducing Agent

Tetramethyldisiloxane: A Practical Organosilane Reducing Agent

Nanogold(0)-Catalyzed Addition of Heteroelement σ Linkages to Functional Groups

Highly Selective Reduction of Bio-Based Furfural to Furfuryl Alcohol Catalyzed by Supported KF with Polymethylhydrosiloxane (PMHS)

Contact Info

Product

Resources

About