597-67-1Relevant articles and documents
Light-Promoted Transfer of an Iridium Hydride in Alkyl Ether Cleavage
Fast, Caleb D.,Schley, Nathan D.
supporting information, p. 3291 - 3297 (2021/10/12)
A catalytic, light-promoted hydrosilylative cleavage reaction of alkyl ethers is reported. Initial studies are consistent with a mechanism involving heterolytic silane activation followed by delivery of a photohydride equivalent to a silyloxonium ion generated in situ. The catalyst resting state is a mixture of Cp*Ir(ppy)H (ppy = 2-phenylpyridine-κC,N) and a related hydride-bridged dimer. Trends in selectivity in substrate reduction are consistent with nonradical mechanisms for C-O bond scission. Irradiation of Cp*Ir(ppy)H with blue light is found to increase the rate of hydride delivery to an oxonium ion in a stoichiometric test. A comparable rate enhancement is found in carbonyl hydrosilylation catalysis, which operates through a related mechanism also involving Cp*Ir(ppy)H as the resting state.
High Production of Hydrogen on Demand from Silanes Catalyzed by Iridium Complexes as a Versatile Hydrogen Storage System
Ventura-Espinosa, David,Sabater, Sara,Carretero-Cerdán, Alba,Baya, Miguel,Mata, Jose A.
, p. 2558 - 2566 (2018/03/13)
The catalytic dehydrogenative coupling of silanes and alcohols represents a convenient process to produce hydrogen on demand. The catalyst, an iridium complex of the formula [IrCp?(Cl)2(NHC)] containing an N-heterocyclic carbene (NHC) ligand functionalized with a pyrene tag, catalyzes efficiently the reaction at room temperature producing H2 quantitatively within a few minutes. As a result, the dehydrogenative coupling of 1,4-disilabutane and methanol enables an effective hydrogen storage capacity of 4.3 wt % that is as high as the hydrogen contained in the dehydrogenation of formic acid, positioning the silane/alcohol pair as a potential liquid organic hydrogen carrier for energy storage. In addition, the heterogenization of the iridium complex on graphene presents a recyclable catalyst that retains its activity for at least 10 additional runs. The homogeneous distribution of catalytic active sites on the basal plane of graphene prevents diffusion problems, and the reaction kinetics are maintained after immobilization.
Metal-Free Catalytic Reductive Cleavage of Enol Ethers
Chulsky, Karina,Dobrovetsky, Roman
supporting information, p. 6804 - 6807 (2018/11/02)
In contrast to the well-known reductive cleavage of the alkyl-O bond, the cleavage of the alkenyl-O bond is much more challenging especially using metal-free approaches. Unexpectedly, alkenyl-O bonds were reductively cleaved when enol ethers were reacted with Et3SiH and a catalytic amount of B(C6F5)3. Supposedly, this reaction is the result of a B(C6F5)3-catalyzed tandem hydrosilylation reaction and a silicon-assisted β-elimination. A mechanism for this cleavage reaction is proposed based on experiments and density functional theory (DFT) calculations.
Wettability-Driven Palladium Catalysis for Enhanced Dehydrogenative Coupling of Organosilanes
Lin, Jian-Dong,Bi, Qing-Yuan,Tao, Lei,Jiang, Tao,Liu, Yong-Mei,He, He-Yong,Cao, Yong,Wang, Yang-Dong
, p. 1720 - 1727 (2017/08/15)
Direct coupling of Si-H bonds has emerged as a promising strategy for designing chemically and biologically useful organosilicon compounds. Heterogeneous catalytic systems sufficiently active, selective, and durable for dehydrosilylation reactions under mild conditions have been lacking to date. Herein, we report that the hydrophobic characteristics of the underlying supports can be advantageously utilized to enhance the efficiency of palladium nanoparticles (Pd NPs) for the dehydrogenative coupling of organosilanes. As a result of this prominent surface wettability control, the modulated catalyst showed a significantly higher level of efficiency and durability characteristics toward the dehydrogenative condensation of organosilanes with water, alcohols, or amines in comparison to existing catalysts. In a broader context, this work illustrates a powerful approach to maximize the performance of supported metals through surface wettability modulation under catalytically relevant conditions.
Synthesis of nitrogen and sulfur co-doped hierarchical porous carbons and metal-free oxidative coupling of silanes with alcohols
Chen, Bingfeng,Li, Fengbo,Mei, Qingqing,Yang, Youdi,Liu, Huizhen,Yuan, Guoqing,Han, Buxing
supporting information, p. 13019 - 13022 (2017/12/15)
Hierarchically porous N and S co-doped carbon was prepared by using 2,5-dihydroxy-1,4-benzoquinone as the carbon source, thiourea as the N and S source, and SiO2 particles as the template. Using the material as the catalyst, oxidative coupling of silanes with alcohols was conducted for the first time under metal-free conditions.
Silica-supported ultra small gold nanoparticles as nanoreactors for the etherification of silanes
Wang, Cui,Lin, Xijie,Ge, Yuzhen,Shah, Zameer Hussain,Lu, Rongwen,Zhang, Shufen
, p. 102102 - 102108 (2016/11/09)
Ultra small gold nanoparticles supported by porous silica (Au-SiO2) were successfully synthesized. Due to enrichment of reactants by silica, the Au-SiO2 particles functioned as nanoreactors for catalytic etherification of silanes wit
Catalytic reduction of CO2with organo-silanes using [Ru3(CO)12]
Jurado-Vázquez, Tamara,Ortiz-Cervantes, Carmen,García, Juventino J.
, p. 8 - 13 (2016/09/28)
The reaction of carbon dioxide with Et3SiH in the presence of catalytic amounts of [Ru3(CO)12] as a catalytic precursor was achieved to produce silyl formate (Et3SiOCOH) 1s with a TON of 9000. A similar reaction in the presence of KF yielded potassium formate (8s) in a one-pot protocol with high selectivity using water or MeCN as the solvent. In the current report the complete reduction of carbon dioxide to methane was achieved, with the use of a more reactive silane (phenylsilane). A catalytically relevant species was the ruthenium cluster [H4Ru4(CO)12]. This is the second report on the hydrosilylation of carbon dioxide catalyzed by highly active and readily available ruthenium clusters and this is the first report of hydrosilylation of CO2to methane.
Dehydrogenative coupling of alcohol with hydrosilane catalyzed by an iron complex
Fukumoto, Kozo,Kasa, Michiho,Nakazawa, Hiroshi
, p. 219 - 221 (2015/03/30)
Silane alcoholysis of triethylsilane (Et3SiH) with alcohol (ROH) with the help of CpFe(CO)2Me (1) has been achieved to produce triethylsilyl ether (ROSiEt3) under the thermal condition. For some alcohols, the iron complex
Photo Lewis acid generators: Photorelease of B(C6F5)3 and applications to catalysis
Khalimon, Andrey Y.,Shaw, Bryan K.,Marwitz, Adam J. V.,Piers, Warren E.,Blackwell, James M.,Parvez, Masood
supporting information, p. 18196 - 18206 (2015/10/28)
A series of molecules capable of releasing of the strong organometallic Lewis acid B(C6F5)3 upon exposure to 254 nm light have been developed. These photo Lewis acid generators (PhLAGs) can now serve as photoinitiators for several important B(C6F5)3-catalyzed reactions. Herein is described the synthesis of the triphenylsulfonium and diphenyliodonium salts of carbamato- and hydridoborates, their establishment as PhLAGs, and studies aimed at defining the mechanism of borane release. Factors affecting these photolytic reactions and the application of this concept to photoinduced hydrosilylation reactions and construction of siloxane scaffolds are also discussed.
METHODS AND COMPOUNDS FOR PHOTO LEWIS ACID GENERATION AND USES THEREOF
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Page/Page column 37; 38, (2013/10/21)
There are disclosed masked Lewis acids into compounds in which the Lewis acid can be released by exposure of the compound to light, especially ultraviolet light. These compounds can be represented by the following formula (I): ([(AEX(3-n))(n+1)Yn](n+1)-)m(Qm+)(n+1) (I). wherein briefly, E represents boron or aluminium, X is an aryl group and Y is -Ar'EAX,. These compounds are used as catalyst for hydrosilylation reaction, crosslinking of polymers, or ester deprotection reactions as photo Lewis acid generator (PhLAG).
