- Electrochemistry as a correlation tool candidate with catalytic activities in Ru-catalyzed hydrolytic oxidation of organosilane
-
Electrochemical parameters measured from a series of ruthenium complexes are nicely correlated with both structural changes and catalytic activities of those species under the reaction conditions providing a possibility that electrochemistry may offer a facile tool for better understanding of some transition metal-catalyzed reactions.
- Na, Youngim,Lee, Chongmok,Pak, Jae Youn,Lee, Kuk Hwa,Chang, Sukbok
-
-
Read Online
- Cobalt single atoms anchored on nitrogen-doped porous carbon as an efficient catalyst for oxidation of silanes
-
The oxidation reactions of organic compounds are important transformations for the fine and bulk chemical industry. However, they usually involve the use of noble metal catalysts and suffer from toxic or environmental issues. Here, an efficient, environmentally friendly, and atomically dispersed Co catalyst (Co-N-C) was preparedviaa simple, porous MgO template and etching method using 1,10-phenanthroline as C and N sources, and CoCl2·6H2O as the metal source. The obtained Co-N-C catalyst exhibits excellent catalytic performance for the oxidation of silanes with 97% isolated yield of organosilanol under mild conditions (room temperature, H2O as an oxidant, 1.8 h), and good stability with 95% isolated yield after nine consecutive reactions. The turnover frequency (TOF) is as high as 381 h?1, exceeding those of most non-noble metal catalysts and some noble metal catalysts. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), extended X-ray absorption fine structure (EXAFS), and wavelet transform (WT) spectroscopy corroborate the existence of atomically dispersed Co. The coordination numbers of Co affected by the pyrolysis temperature in Co-N-C-700, Co-N-C-800, and Co-N-C-900 are 4.1, 3.6, and 2.2, respectively. Owing to a higher Co-N3content, Co-N-C-800 shows more outstanding catalytic performance than Co-N-C-700 and Co-N-C-800. Moreover, density functional theory (DFT) calculations reveal that the Co-N3structure exhibits more activity compared with Co-N4and Co-N2, which is because the Co atom in Co-N3was bound with both H atom and Si atom, and it induced the longest Si-H bond.
- Yang, Fan,Liu, Zhihui,Liu, Xiaodong,Feng, Andong,Zhang, Bing,Yang, Wang,Li, Yongfeng
-
p. 1026 - 1035
(2021/02/09)
-
- Selective Electrochemical Hydrolysis of Hydrosilanes to Silanols via Anodically Generated Silyl Cations
-
The first electrochemical hydrolysis of hydrosilanes to silanols under mild and neutral reaction conditions is reported. The practical protocol employs commercially available and cheap NHPI as a hydrogen-atom transfer (HAT) mediator and operates at room temperature with high selectivity, leading to various valuable silanols in moderate to good yields. Notably, this electrochemical method exhibits a broad substrate scope and high functional-group compatibility, and it is applicable to late-stage functionalization of complex molecules. Preliminary mechanistic studies suggest that the reaction appears to proceed through a nucleophilic substitution reaction of an electrogenerated silyl cation with H2O.
- Liang, Hao,Wang, Lu-Jun,Ji, Yun-Xing,Wang, Han,Zhang, Bo
-
supporting information
p. 1839 - 1844
(2020/12/01)
-
- Metal-free hydrogen evolution cross-coupling enabled by synergistic photoredox and polarity reversal catalysis
-
A synergistic combination of photoredox and polarity reversal catalysis enabled a hydrogen evolution cross-coupling of silanes with H2O, alcohols, phenols, and silanols, which afforded the corresponding silanols, monosilyl ethers, and disilyl ethers, respectively, in moderate to excellent yields. The dehydrogenative cross-coupling of Si-H and O-H proceeded smoothly with broad substrate scope and good functional group compatibility in the presence of only an organophotocatalyst 4-CzIPN and a thiol HAT catalyst, without the requirement of any metals, external oxidants and proton reductants, which is distinct from the previously reported photocatalytic hydrogen evolution cross-coupling reactions where a proton reduction cocatalyst such as a cobalt complex is generally required. Mechanistically, a silyl cation intermediate is generated to facilitate the cross-coupling reaction, which therefore represents an unprecedented approach for the generation of silyl cationviavisible-light photoredox catalysis.
- Cao, Jilei,Lu, Kanghui,Ma, Lishuang,Yang, Xiaona,Zhou, Rong
-
supporting information
p. 8988 - 8994
(2021/11/23)
-
- Catalytic Enantioselective Dehydrogenative Si-O Coupling to Access Chiroptical Silicon-Stereogenic Siloxanes and Alkoxysilanes
-
A rhodium-catalyzed enantioselective construction of triorgano-substituted silicon-stereogenic siloxanes and alkoxysilanes is developed. This process undergoes a direct intermolecular dehydrogenative Si-O coupling between dihydrosilanes with silanols or alocohols, giving access to a variety of highly functionalized chiral siloxanes and alkoxysilanes in decent yields with excellent stereocontrol, that significantly expand the chemical space of the silicon-centered chiral molecules. Further utility of this process was illustrated by the construction of CPL-active (circularly polarized luminescence) silicon-stereogenic alkoxysilane small organic molecules. Optically pure bis-alkoxysilane containing two silicon-stereogenic centers and three pyrene groups displayed a remarkable glum value with a high fluorescence quantum efficiency (glum = 0.011, φF = 0.55), which could have great potential application prospects in chiral organic optoelectronic materials.
- Zhu, Jiefeng,Chen, Shuyou,He, Chuan
-
supporting information
p. 5301 - 5307
(2021/05/04)
-
- Photocatalyzed cross-dehydrogenative coupling of silanes with alcohols and water
-
An efficient method for the dehydrogenative coupling of silanes with alcohols under photocatalysis was developed. The reaction proceeded in the presence of Ru(bpy)3Cl2(0.5 mol%) under visible light irradiation in acetonitrile at room temperature. The developed methodology was also applicable for the synthesis of silanols using water as a coupling partner.
- Lv, Haiping,Laishram, Ronibala Devi,Chen, Jingchao,Khan, Ruhima,Zhu, Yuanbin,Wu, Shiyuan,Zhang, Jianqiang,Liu, Xingyuan,Fan, Baomin
-
supporting information
p. 3660 - 3663
(2021/04/16)
-
- METHOD FOR PRODUCING SILANOLS AND NOVEL SILANOLS
-
PROBLEM TO BE SOLVED: To provide a method for efficiently producing silanols useful as functional chemicals, and to provide novel silanols. SOLUTION: There is provided a method for producing silanols including a reaction step of reacting alkoxysilanes having Si-OR bonds (R represents a hydrocarbon group having 1 to 6 carbon atoms) with water or heavy water in the presence of a catalyst, wherein a method for producing silanols having an Si-OR' bond (R' represents a hydrogen atom or a deuterium atom) is characterized in that the catalyst is an inorganic solid acid catalyst having a regular pore structure. There is also provided novel silanols obtained thereby. SELECTED DRAWING: None COPYRIGHT: (C)2021,JPOandINPIT
- -
-
Paragraph 0053-0054; 0057; 0073-0074
(2021/08/13)
-
- Mechanistic Studies on the Hexadecafluorophthalocyanine–Iron-Catalyzed Wacker-Type Oxidation of Olefins to Ketones**
-
The hexadecafluorophthalocyanine–iron complex FePcF16 was recently shown to convert olefins into ketones in the presence of stoichiometric amounts of triethylsilane in ethanol at room temperature under an oxygen atmosphere. Herein, we describe an extensive mechanistic investigation for the conversion of 2-vinylnaphthalene into 2-acetylnaphthalene as model reaction. A variety of studies including deuterium- and 18O2-labeling experiments, ESI-MS, and 57Fe M?ssbauer spectroscopy were performed to identify the intermediates involved in the catalytic cycle of the oxidation process. Finally, a detailed and well-supported reaction mechanism for the FePcF16-catalyzed Wacker-type oxidation is proposed.
- Grinenko, Vadim,Klau?, Hans-Henning,Kn?lker, Hans-Joachim,Puls, Florian,Seewald, Felix
-
p. 16776 - 16787
(2021/11/04)
-
- METHOD OF PREPARING SILANOLS WITH SELECTIVE CYTOCHROME P450 VARIANTS AND RELATED COMPOUNDS AND COMPOSITIONS
-
This disclosure provides a method of preparing a silanol-functional organosilicon compound with a cytochrome P450 variant that facilitates the oxidization of a silyl hydride group to a silanol group in the presence of oxygen. The method includes combining the cytochrome P450 variant and an organosilicon compound having at least one silicon-bonded hydrogen atom to give a reaction mixture and exposing the reaction mixture to oxygen to oxidize the organosilicon compound, thereby preparing the silanol-functional organosilicon compound. Cytochrome P450 variants suitable for use in the method are also disclosed, along with methods for engineering and optimizing the same. Nucleic acids encoding the cytochrome P450 variants and compositions, expression vectors, and host cells including the same are also disclosed.
- -
-
Paragraph 00122-00123
(2021/08/27)
-
- Silicon-center chiral silicon-oxygen compound and preparation method thereof
-
The invention belongs to the field of chiral silicon synthesis, and discloses a silicon-center chiral silicon-oxygen compound. The compound has a structure represented by general formula I shown in the specification. In the formula I, X is Si(R)n or a formula also shown in the specification, R is selected from alkyl, cycloalkyl and aryl, R is selected from alkyl, substituted phenyl and aryl, R is selected from alkyl, phenyl and substituted phenyl, n is 3, the three R are the same or different, R is selected from hydrogen and (C1-C4) alkyl, m is selected from 0, 1, 2 and 3, and Y is selected from substituted phenyl, substituted pyrenyl, aryl, heteroaryl and cycloalkyl. The invention also discloses a preparation method of the compound. Various highly functionalized chiral siloxanes and silyl ethers are obtained with good chemical, regional and stereo control and high yield, the variety of silicon center chiral compounds is expanded, and the method has the advantages of high enantioselectivity, wide substrate application range, mild reaction conditions, atom economy and the like. In addition, the compound provided by the invention has a huge application prospect in chiral organic photoelectric materials.
- -
-
Paragraph 0106-0109; 0111-0112; 0116
(2021/07/24)
-
- Highly Selective Hydroxylation and Alkoxylation of Silanes: One-Pot Silane Oxidation and Reduction of Aldehydes/Ketones
-
An efficient chemoselective iridium-catalyzed method for the hydroxylation and alkoxylation of organosilanes to generate hydrogen gas and silanols or silyl ethers was developed. A variety of sterically hindered silanes with alkyl, aryl, and ether groups were tolerated. Furthermore, this atom-economical catalytic protocol can be used for the synthesis of silanediols and silanetriols. A one-pot silane oxidation and chemoselective reduction of aldehydes/ketones was also realized.
- Luo, Nianhua,Liao, Jianhua,Ouyang, Lu,Wen, Huiling,Zhong, Yuhong,Liu, Jitian,Tang, Weiping,Luo, Renshi
-
p. 165 - 171
(2020/01/21)
-
- Selective Enzymatic Oxidation of Silanes to Silanols
-
Compared to the biological world's rich chemistry for functionalizing carbon, enzymatic transformations of the heavier homologue silicon are rare. We report that a wild-type cytochrome P450 monooxygenase (P450BM3 from Bacillus megaterium, CYP102A1) has promiscuous activity for oxidation of hydrosilanes to give silanols. Directed evolution was applied to enhance this non-native activity and create a highly efficient catalyst for selective silane oxidation under mild conditions with oxygen as the terminal oxidant. The evolved enzyme leaves C?H bonds present in the silane substrates untouched, and this biotransformation does not lead to disiloxane formation, a common problem in silanol syntheses. Computational studies reveal that catalysis proceeds through hydrogen atom abstraction followed by radical rebound, as observed in the native C?H hydroxylation mechanism of the P450 enzyme. This enzymatic silane oxidation extends nature's impressive catalytic repertoire.
- Arnold, Frances H.,B?hr, Susanne,Brinkmann-Chen, Sabine,Garcia-Borràs, Marc,Houk, K. N.,Katsoulis, Dimitris E.,Roberts, John M.
-
supporting information
p. 15507 - 15511
(2020/05/05)
-
- Synthesis of a Gold–Metal Oxide Core–Satellite Nanostructure for In Situ SERS Study of CuO-Catalyzed Photooxidation
-
This work reports on an assembling–calcining method for preparing gold–metal oxide core–satellite nanostructures, which enable surface-enhanced Raman spectroscopic detection of chemical reactions on metal oxide nanoparticles. By using the nanostructure, we study the photooxidation of Si?H catalyzed by CuO nanoparticles. As evidenced by the in situ spectroscopic results, oxygen vacancies of CuO are found to be very active sites for oxygen activation, and hydroxide radicals (*OH) adsorbed at the catalytic sites are likely to be the reactive intermediates that trigger the conversion from silanes into the corresponding silanols. According to our finding, oxygen vacancy-rich CuO catalysts are confirmed to be of both high activity and selectivity in photooxidation of various silanes.
- Bai, Lu,Fan, Chenghao,Hu, Yanfang,Li, Yonglong,Liu, Jun,Shi, Faxing,Xie, Wei,Yang, Ling,Zhang, Kaifu,Zhao, Yaran
-
p. 18003 - 18009
(2020/08/21)
-
- Heterocyclization and solvent interception upon oxidative triflamidation of allyl ethers, amines and silanes
-
The reactions of triflamide with a series of mono- and diallyl heteroatomic compounds have been studied in the presence of various oxidants (t-BuOI, NBS, NIS). The reaction course was found to be strongly dependent on the oxidant leading to the products of bis(triflamidation) or heterocyclization in the system (t-BuOCl + NaI), or amidines – the Ritter-type solvent interception halosulfamidation products – with N-bromo- or N-iodosuccinimide. The amidines were converted to imidazolines in high yield via the base-induced heterocyclization.
- Ganin, Anton S.,Moskalik, Mikhail Yu.,Astakhova, Vera V.,Sterkhova, Irina V.,Shainyan, Bagrat A.
-
-
- Selective Manganese-Catalyzed Oxidation of Hydrosilanes to Silanols under Neutral Reaction Conditions
-
The first manganese-catalyzed oxidation of organosilanes to silanols with H2O2 under neutral reaction conditions has been accomplished. A variety of organosilanes with alkyl, aryl, alknyl, and heterocyclic substituents were tolerated, as well as sterically hindered organosilanes. The oxidation appears to proceed by a concerted process involving a manganese hydroperoxide species. Featuring mild reaction conditions, fast oxidation, and no waste byproducts, the protocol allows a low-cost, eco-benign synthesis of both silanols and silanediols.
- Wang, Kaikai,Zhou, Jimei,Jiang, Yuting,Zhang, Miaomiao,Wang, Chao,Xue, Dong,Tang, Weijun,Sun, Huamin,Xiao, Jianliang,Li, Chaoqun
-
supporting information
p. 6380 - 6384
(2019/05/06)
-
- Silanol organic compound and preparation method thereof
-
The invention belongs to the technical field of chemical industry, and discloses a silanol organic compound and a preparation method thereof. The preparation method of the silanol organic compound takes silane and water as reaction raw materials and sulfoxide as a catalyst, and carries out reaction by heating under an argon atmosphere to prepare a corresponding silanol product. The product prepared by the method has the advantages of high yield, good selectivity, mild reaction, cheap catalyst, no metal participation, environmental protection, good atom economy, and wide application range, andthe use of the water as an oxygen source accords with the development concept of green chemistry.
- -
-
Paragraph 0055
(2019/07/04)
-
- Tellurorhodamine photocatalyzed aerobic oxidation of organo-silanes and phosphines by visible-light
-
Tellurorhodamine, 9-mesityl-3,6-bis(dimethylamino)telluroxanthylium hexafluorophosphate (1), photocatalytically oxidizes aromatic and aliphatic silanes and triphenyl phosphine under mild aerobic conditions. Under irradiation with visible light, 1 can react with self-sensitized 1O2 to generate the active telluroxide oxidant (2). Silanes are oxidized to silanols and triphenyl phosphine is oxidized to triphenyl phoshine oxide either using 2, or 1 with aerobic irradiation. Kinetic experiments coupled with a computational study elucidate possible mechanisms of oxidation for both silane and phosphine substrates. First-order rates were observed in the oxidation of triphenyl phosphine and methyldiphenyl silane, indicating a substitution like mechanism for substrate binding to the oxidized tellurium(iv). Additionally, these reactions exhibited a rate-dependence on water. Oxidations were typically run in 50:50 water/methanol, however, the absence of water decreased the rates of silane oxidation to a greater degree than triphenyl phosphine oxidation. Parallel results were observed in solvent kinetic isotope experiments using D2O in the solvent mixture. The rates of oxidation were slowed to a greater degree in silane oxidation by 2 (kH/kD = 17.30) than for phosphine (kH/kD = 6.20). Various silanes and triphenyl phosphine were photocatalytically oxidized with 1 (5%) under irradiation with warm white LEDs using atmospheric oxygen as the terminal oxidant.
- Rettig, Irving D.,Van, Jackson,Brauer, Jacob B.,Luo, Wentai,McCormick, Theresa M.
-
supporting information
p. 5665 - 5673
(2019/05/10)
-
- Hydrogenation of silyl formates: sustainable production of silanol and methanol from hydrosilane and carbon dioxide
-
A new process for simultaneously obtaining two chemical building blocks, methanol and silanol, was realized starting from silyl formates which can be derived from silane and carbon dioxide. Understanding the reaction mechanism enabled us to improve the reaction efficiency by the addition of a small amount of methanol.
- Koo, Jangwoo,Kim, Seung Hyo,Hong, Soon Hyeok
-
supporting information
p. 4995 - 4998
(2018/05/23)
-
- Metal-free visible-light-mediated aerobic oxidation of silanes to silanols
-
Oxidation of silanes into silanols using water/air has attracted considerable attention. The known methods with no exception required a metal catalyst. Herein we report the first metal-free method: 2 mol% Rose Bengal as the catalyst, air (O2) as the oxidant, water as the additive and under visible light irradiation. While this method produces various silanols in a simple, cost-effective, efficient (92%–99% yields) and scalable fashion, its reaction mechanism is very different than the reported ones associated with metal catalysis.
- Wang, Jing,Li, Bin,Liu, Li-Chuan,Jiang, Chenran,He, Tao,He, Wei
-
p. 1594 - 1599
(2018/08/22)
-
- Synthesis of Aryl Silacarboxylates via Palladium-Catalyzed C-O Bond Formation of Silacarboxylic Acids and Aryl Iodides
-
The first palladium-catalyzed C-O bond formation method for the synthesis of silacarboxylates by silacarboxylic acids with a broad range of aryl iodides and iodo-N-heterocycles is reported. Electron-deficient, electron-rich, and sterically hindered aryl iodides were well-tolerated to furnish the corresponding aryl silacarboxylates in moderate to excellent yields. Active functional groups, such as -NH2, -CHO, and allyl-, showed good tolerance, even in the large-scale synthesis. Double and triple esterification were also demonstrated to be effective.
- Liang, Jin-Yan,Shen, Shou-Jie,Xu, Xiao-Hu,Fu, Yun-Long
-
p. 6627 - 6631
(2018/10/31)
-
- Single-Site AuI Catalyst for Silane Oxidation with Water
-
Single-site Au anchored on mpg-C3N4 (519 ppm Au loading) is developed as a highly active, selective, and stable catalyst for the oxidation of silanes with water with a turnover frequency as high as 50 200 h?1, far exceeding most known catalysts based on total gold content. Other hydrosilanes bearing unsaturated functional groups also lead to corresponding silanols under mild reaction conditions without formation of any side products in good or excellent yields. The spherical aberration correction electron microscopy and extended X-ray absorption fine structure measurements both confirm the atomic dispersion of Au atoms stabilized by mpg-C3N4. The coordination of the catalytically active AuI by three nitrogen or carbon atoms in the tri-s-triazine repeating units not only prevents the Au atoms from aggregation, but also renders the surface AuI highly active, which is completely different than homogeneous AuI species.
- Chen, Zheng,Zhang, Qi,Chen, Wenxing,Dong, Juncai,Yao, Hurong,Zhang, Xiangbo,Tong, Xuanjue,Wang, Dingsheng,Peng, Qing,Chen, Chen,He, Wei,Li, Yadong
-
-
- Hydrogenation and Hydrosilylation of Nitrous Oxide Homogeneously Catalyzed by a Metal Complex
-
Due to its significant contribution to stratospheric ozone depletion and its potent greenhouse effect, nitrous oxide has stimulated much research interest regarding its reactivity modes and its transformations, which can lead to its abatement. We report the homogeneously catalyzed reaction of nitrous oxide (N2O) with H2. The reaction is catalyzed by a PNP pincer ruthenium complex, generating efficiently only dinitrogen and water, under mild conditions, thus providing a green, mild methodology for removal of nitrous oxide. The reaction proceeds through a sequence of dihydrogen activation, "O"-atom transfer, and dehydration, in which metal-ligand cooperation plays a central role. This approach was further developed to catalytic O-transfer from N2O to Si-H bonds.
- Zeng, Rong,Feller, Moran,Ben-David, Yehoshoa,Milstein, David
-
supporting information
p. 5720 - 5723
(2017/05/04)
-
- Reactions of silicon hydrides catalyzed by rhodium(III) sulfoxide complexes
-
Dehydrocondensation reactions of silicon hydrides catalyzed by the rhodium(III) complex [RhCl3(Me2SO)3] in the absence of the second substrate were studied. It was found that the complex [RhCl3(Me2SO)3] catalyzed the dehydrocondensation reaction with the formation of compounds containing siloxane bonds. Analysis of NMR spectra has shown that the reaction of [RhCl3(Me2SO)3] with silicon hydride includes sequential desoxygenation of sulfoxide ligands to sulfide ligands with the complex [RhCl3(Me2S)3] formation.
- Eliseeva,Prudnikova,Panikorovskii,Skvortsov
-
p. 1884 - 1886
(2017/09/25)
-
- Wettability-Driven Palladium Catalysis for Enhanced Dehydrogenative Coupling of Organosilanes
-
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.
- 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)
-
- A method for catalytic synthesis of silanol
-
The invention discloses a method for catalytically synthesizing silanol and relates to the fields of organic chemicals and fine chemicals. The method is essentially a transition metal catalyzed organic synthesis reaction. In the method, the raw materials comprise organosilane and a clean oxidant, a used catalyst is inexpensive copper salt, the raw material is heated and stirred to react without a solvent so as to rapidly produce silanol at a moderate temperature. By adopting the method, the reaction time is 3-12 hours. The mole ratio of the organosilane to the clean oxidant is 1:(1-5), the copper salt as the catalyst accounts for 1-10mol% of the mole number of the organosilane, the raw materials react at a temperature of 50-80 DEG C, and then the silanol can be greatly yielded after simple posttreatment. The oxidant used in the method is safe and nontoxic, and the catalyst used in the method is cheap and easily available. The method disclosed by the invention is a very simple and practical method for synthesizing silanol.
- -
-
Paragraph 0016; 0037; 0038
(2017/07/12)
-
- Plasma-Assisted Synthesis of Monodispersed and Robust Ruthenium Ultrafine Nanocatalysts for Organosilane Oxidation and Oxygen Evolution Reactions
-
We report a facile and general approach for preparing ultrafine ruthenium nanocatalysts by using a plasma-assisted synthesis at 2 supports. This gives robust catalysts with excellent activities in both organosilane oxidation and the oxygen evolution reaction.
- Gnanakumar, Edwin S.,Ng, Wesley,Co?kuner Filiz, Bilge,Rothenberg, Gadi,Wang, Sheng,Xu, Hualong,Pastor-Pérez, Laura,Pastor-Blas, M. Mercedes,Sepúlveda-Escribano, Antonio,Yan, Ning,Shiju, N. Raveendran
-
p. 4159 - 4163
(2017/10/23)
-
- Instantaneous Conversion of [11C]CO2 to [11C]CO via Fluoride-Activated Disilane Species
-
The development of a fast and novel methodology to generate carbon-11 carbon monoxide ([11C]CO) from cyclotron-produced carbon-11 carbon dioxide ([11C]CO2) mediated by a fluoride-activated disilane species is described. This methodology allows up to 74 % conversion of [11C]CO2 to [11C]CO using commercially available reagents, readily available laboratory equipment and mild reaction conditions (room temperature). As proof of utility, radiochemically pure [carbonyl-11C]N-benzylbenzamide was successfully synthesized from produced [11C]CO in up to 74 % radiochemical yield (RCY) and >99 % radiochemical purity (RCP) in ≤10 min from end of [11C]CO2 delivery.
- Taddei, Carlotta,Bongarzone, Salvatore,Gee, Antony D.
-
supporting information
p. 7682 - 7685
(2017/06/06)
-
- Method for synthesizing silanol from silane through catalytic oxidation by bipyridine manganese catalyst
-
The invention discloses a method for synthesizing silanol from silane through catalytic oxidation by a bipyridine manganese catalyst. The method employs a bipyridine manganese complex formed by coordination of a manganese salt and a dipyridine compound as a catalyst and clean environment-friendly hydrogen peroxide as an oxidizing agent for catalytic oxidation of silane into silanol. Compared with conventional methods, the method provided by the invention has the advantages that the catalyst is low in price; the preparation method is simple; raw materials are easily available; and the method is low in the usage amount of the catalyst, wide in the range of usable substrates, mild in reaction conditions, simple to operate, friendly to environment, short in reaction time, high in yield, good in selectivity, low in industrialization cost, etc.
- -
-
Paragraph 0014; 0015; 0016; 0017; 0018; 0019; 0020-0046
(2018/01/11)
-
- A bentonite-gold nanohybrid as a heterogeneous green catalyst for selective oxidation of silanes
-
A highly efficient, environmentally benign and reusable heterogeneous bentonite-gold nanohybrid catalyst was designed and synthesized. This heterogeneous catalyst could efficaciously catalyse the oxidation of organosilanes to silanols. The reaction is 98.7% atom economical and the products were obtained in excellent yield without the formation of disiloxanes as byproducts. The catalyst was also well applicable for the gram scale preparation of silanols.
- Maya,John, Jubi,Varma, R. Luxmi
-
supporting information
p. 10625 - 10628
(2016/09/02)
-
- Hydrosilane-assisted formation of metal nanoparticles on graphene oxide
-
Metal nanoparticles were formed on graphene oxide by a deposition process with hydrosilane, giving thin layer metalgraphene oxide (metal/GO) composites. The particle size and catalytic activity could be controlled by varying the hydrosilane amount. Hydrosilane prevented the aggregation of GO layers by surface functionalization via silane coupling reaction. The metal/GO composites were evaluated as catalysts in hydrosilane oxidation.
- Saito, Akinori,Kinoshita, Hiroshi,Shimizu, Ken-Ichi,Nishina, Yuta
-
supporting information
p. 67 - 73
(2016/01/27)
-
- Stereoselective Catalysis Achieved through in Situ Desymmetrization of an Achiral Iron Catalyst Precursor
-
Stereoselective catalysis is described that proceeds with catalyst control but without the need to synthesize preformed chiral catalysts or ligands. Iron-based catalysts were discovered to effect the stereoselective polymerization of lactides starting from a single achiral precursor and the proper choice of an achiral silanol additive. Spectroscopic analysis of the polymer revealed that the stereoselectivity originates from an enantiomorphic site rather than a chain end stereocontrol mechanism. Iron intermediates that are stereogenic at iron are proposed to form in situ as a result of desymmetrization that occurs from a change in the metal coordination number. The proposed mechanism is supported by a combination of spectroscopic measurements, model complexes, kinetic measurements, and DFT calculations.
- Manna, Cesar M.,Kaur, Aman,Yablon, Lauren M.,Haeffner, Fredrik,Li, Bo,Byers, Jeffery A.
-
supporting information
p. 14232 - 14235
(2015/11/27)
-
- Pinacol couplings of a series of aldehydes and ketones with SmI2/Sm/Me3SiCl in DME
-
The pinacol coupling is one of the most significant methods to synthesize vic-diols. The combination of samarium diiodide (SmI2) and samarium metal successfully induces the selective pinacol couplings of not only aromatic aldehydes and ketones but also aliphatic ones in the presence of trimethylchlorosilane (Me3SiCl) in 1,2-dimethoxyethane (DME). DME is the most suitable solvent for the reduction system using SmI2 and Me3SiCl. Me3SiCl, a widely available additive, prevents the decomposition of the formed vic-diols, i.e., meso-isomers, and controls their stereochemistry. In particular, the pinacol couplings of sterically hindered aliphatic aldehydes and ketones proceed with excellent diastereoselectivities to afford dl-isomers in good yields.
- Yoshimura, Aya,Saeki, Tomokazu,Nomoto, Akihiro,Ogawa, Akiya
-
p. 5347 - 5355
(2015/07/15)
-
- Visible-Light-Promoted Generation of Hydrogen from the Hydrolysis of Silanes Catalyzed by Rhodium(III) Porphyrins
-
Visible-light-promoted hydrolysis of silanes catalyzed by (TAP)Rh-I to produce silanols and dihydrogen efficiently under mild conditions was reported. (TAP)Rh-H was observed as the key intermediate through stoichiometric activation of the Si-H bond by (TAP)Rh-I. Addition of water drove the stoichiometric activation of Si-H into catalysis.
- Yu, Mengmeng,Jing, Huize,Liu, Xu,Fu, Xuefeng
-
p. 5754 - 5758
(2016/01/12)
-
- Nonhydrolytic synthesis of silanols by the hydrogenolysis of benzyloxysilanes
-
The hydrogenolysis of benzyloxysilanes was smoothly catalyzed by Pd/C in THF to give corresponding silanols under nonhydrolytic conditions. The reaction proved to be applicable to various benzyloxysilanes giving silanemonools, diol, and triol.
- Igarashi, Masayasu,Matsumoto, Tomohiro,Sato, Kazuhiko,Ando, Wataru,Shimada, Shigeru
-
supporting information
p. 429 - 431
(2014/04/17)
-
- Highly selective oxidation of organosilanes with a reusable nanoporous silver catalyst
-
Room temperature highly selective oxidation of organosilanes to organosilanols and organosilyl ethers is achieved in liquid-phase with dealloyed nanoporous silver catalysts. In both cases, aromatic and aliphatic silanes can be effectively converted into the corresponding silanols and silyl ethers by using water and alcohols as oxidant, respectively. Moreover, hydrogen gas is the only by-product and the catalyst can be recycled for several times without evident loss of activity and selectivity.
- Li, Zhiwen,Zhang, Congcong,Tian, Jing,Zhang, Zhonghua,Zhang, Xiaomei,Ding, Yi
-
-
- A novel iron complex for highly efficient catalytic hydrogen generation from the hydrolysis of organosilanes
-
Hydrolytic oxidation of organosilanes based on an iron catalyst is described for the first time. The novel iron complex, [Fe(C6H 5N2O)(CO)(MeCN)3][PF6], exhibits excellent mediating power in the catalytic hydrolysis of organosilanes to produce dihydrogen and organosilanols with turnover numbers approaching 10 4 and turnover frequencies in excess of 102 min -1 under ambient conditions.
- Liang Teo, Alan Kay,Fan, Wai Yip
-
supporting information
p. 7191 - 7194
(2014/07/07)
-
- Organosilane oxidation by water catalysed by large gold nanoparticles in a membrane reactor
-
We show that gold nanoparticles catalyse the oxidation of organosilanes using water as oxidant at ambient conditions. Remarkably, monodispersions of small gold particles (3.5 nm diameter) and large ones (6-18 nm diameter) give equally good conversion rates. This is important because separating large nanoparticles is much easier, and can be done using ultrafiltration instead of nanofiltration. We introduce a simple setup, constructed in-house, where the reaction products are extracted through a ceramic membrane under pressure, leaving the gold nanoparticles intact in the vessel. The nominal substrate/catalyst ratios are ca. 1800:1, with typical TONs of 1500-1600, and TOFs around 800 h-1. But the actual activity of the large nanoparticles is much higher, because most of their gold atoms are "inside", and therefore unavailable. Control experiments confirm that no gold escapes to the membrane permeate. The role of surface oxygen as a possible co-catalyst is discussed. Considering the ease of product separation and the robustness of the ceramic membrane, this approach opens opportunities for actual applications of gold catalysts in water oxidation reactions. The Royal Society of Chemistry 2014.
- Gitis, Vitaly,Beerthuis, Rolf,Shiju, N. Raveendran,Rothenberg, Gadi
-
p. 2156 - 2160
(2014/06/24)
-
- Iridium-catalyzed hydrogen production from hydrosilanes and water
-
The iridium(III) complex [Ir(H)(CF3SO3)(NSiN)(coe)] (NSiN=fac-coordinated bis(pyridine-2-yloxy)methylsilyl, coe=cyclooctene) has been proven to be an effective catalyst precursor for hydrogen production from the hydrolysis of hydrosilanes at room temperature. The reaction performance depends both on the nature of the silane and the solvent. Interestingly, high turnover frequencies of around 105 h-1 were obtained by using Et2SiH2 or (Me2HSi)2O as hydrogen sources and THF as the solvent. Moreover a mechanistic insight into this Ir-catalyzed hydrogen generation process, based on both theoretical calculations and NMR spectroscopy, is reported. The overall catalytic cycle can be viewed as a two-stage process that involves water-promoted Si-H bond activation followed by water splitting by a proton transfer. From hydrosilanes to hydrogen: The iridium(III) complex [Ir(H)(CF3SO 3)(NSiN)(coe)] is an effective homogeneous catalyst precursor for hydrogen production from the hydrolysis of hydrosilanes (NSiN=fac-coordinated bis(pyridine-2-yloxy)methylsilyl, coe=cyclooctene).
- Garces, Karin,Fernandez-Alvarez, Francisco J.,Polo, Victor,Lalrempuia, Ralte,Perez-Torrente, Jesus J.,Oro, Luis A.
-
p. 1691 - 1697
(2014/06/24)
-
- DISILOXANE COMPOUNDS AND THEIR USES
-
A disiloxane having the following structure. Formula (I), Where R1, R3, R4 and R5 are each independently selected from monovalent hydrocarbon radicals having 1 to 4 carbon atoms, aryl, and a hydrocarbon group of 6 to 20 carbon atoms containing an aryl group; R2 is selected from a branched or linear hydrocarbon group of 7 to 15 carbons, a substituted branched or substituted linear hydrocarbon group of 7 to 15 carbons an optionally substituted aryl group, and an alkyl hydrocarbon chain of 4 to 9 carbons having one or more aryl substituents of 6 to 20 carbon atoms or a branched or linear hydrocarbon group of 1 to 6 carbons when R1 and R3 are independently an aryl group, or a hydrocarbon group of 6 to 20 carbon atoms containing an aryl group; Z is a linear or branched divalent hydrocarbon radical of from 2 to 10 (inclusive) carbon atoms and R8 is selected from OH, H, monovalent hydrocarbon radicals of from 1 to 6 carbon atoms and acetyl and each of the subscripts a, b and c are zero or positive provided that a + b + c ≥ 1.
- -
-
Paragraph 0040
(2014/05/24)
-
- Organocatalytic oxidation of organosilanes to silanols
-
The oxidation of organosilanes to silanols constitutes an attractive transformation for both industry and academia. Bypassing the need for stoichiometric oxidants or precious metal catalytic complexes, the first organocatalytic oxidation of silanes has been accomplished. Catalytic amounts of 2,2,2-trifluoroacetophenone, in combination with the green oxidant H 2O2, lead to excellent to quantitative yields in a short reaction time. A variety of alkyl, aryl, alkenyl, and alkynyl substituents can be tolerated, providing an easy, cheap, efficient, and practical solution to a highly desirable transformation.
- Limnios, Dimitris,Kokotos, Christoforos G.
-
p. 2239 - 2243
(2013/10/22)
-
- A discrete octahedrally shaped [Ag6]4+ cluster encapsulated within silicotungstate ligands
-
By the reaction of TBA4H4[γ-SiW 10O36] (TBA = tetra-n-butylammonium) with AgOAc (OAc = acetate) using dimethylphenylsilane as a reductant in acetone, a unique polyoxometalate containing a discrete octahedrally shaped [Ag6] 4+ cluster, TBA8[Ag6(γ-H 2SiW10O36)2]·5H2O, could be synthesized, and the molecular structure was determined.
- Kikukawa, Yuji,Kuroda, Yoshiyuki,Suzuki, Kosuke,Hibino, Mitsuhiro,Yamaguchi, Kazuya,Mizuno, Noritaka
-
p. 376 - 378
(2013/03/13)
-
- Highly efficient generation of hydrogen from the hydrolysis of silanes catalyzed by [RhCl(CO)2]2
-
Catalytic hydrolysis of silanes mediated by chlorodicarbonylrhodium(I) dimer [RhCl(CO)2]2 to produce silanols and dihydrogen efficiently under mild conditions is reported. Second-order kinetics and activation parameters are determined by monitoring the rate of dihydrogen evolution. The mixing of [RhCl(CO)2]2 and HSiCl 3 results in rapid formation of a rhodium silane σ complex.
- Yu, Mengmeng,Jing, Huize,Fu, Xuefeng
-
supporting information
p. 10741 - 10743
(2013/10/22)
-
- Postsynthetic functionalization of a hollow silica nanoreactor with manganese oxide-immobilized metal nanocrystals inside the cavity
-
A postsynthetic protocol of functionalizing the preformed hollow nanoparticles with metal nanocrystals was developed based on galvanic replacement reaction on the Mn3O4 surface inside the cavity. The developed protocol produced hollow nanoreactor systems, in which a high density of ultrafine catalytic nanocrystals of a range of noble metals, such as Pd, Pt, Rh, and Ir and their alloys, are dispersively immobilized on an interior surface enclosed by a selectively permeable silica shell. The fabricated hollow nanoreactor exhibited highly enhanced activity, selectivity, and recyclability in catalyzing the oxidation of hydrosilanes, which are attributable to the synergistic combination of the porous silica nanoshell and the oxide-immobilized catalyst system.
- Kim, Soo Min,Jeon, Mina,Kim, Ki Woong,Park, Jaiwook,Lee, In Su
-
supporting information
p. 15714 - 15717
(2013/11/06)
-
- Gold nanoparticles-catalyzed activation of 1,2-disilanes: Hydrolysis, silyl protection of alcohols and reduction of tert-benzylic alcohols
-
Gold nanoparticles supported on TiO2 catalyze under mild conditions the activation of a series of 1,2-disilanes towards hydrolysis and alcoholysis, with concomitant evolution of H2 gas. For the case of tert-benzyl alcohols, the main or only pathway is reduction to the corresponding alkanes.
- Gryparis, Charis,Stratakis, Manolis
-
p. 10751 - 10753,3
(2020/09/02)
-
- Copper-catalyzed formic acid synthesis from CO2 with hydrosilanes and H2O
-
A copper-catalyzed formic acid synthesis from CO2 with hydrosilanes has been accomplished. The Cu(OAc)2?H 2O-1,2-bis(diphenylphosphino)benzene system is highly effective for the formic acid synthesis under 1 atm of CO2. The TON value approached 8100 in 6 h. The reaction pathway was revealed by in situ NMR analysis and isotopic experiments.
- Motokura, Ken,Kashiwame, Daiki,Miyaji, Akimitsu,Baba, Toshihide
-
p. 2642 - 2645
(2012/08/13)
-
- Diamond-shaped [Ag4]4+ cluster encapsulated by silicotungstate ligands: Synthesis and catalysis of hydrolytic oxidation of silanes
-
An Ag4 diamond is encapsulated by silicotungstate ligands in TBA8[Ag4(DMSO)2(γ-H2SiW 10O36)2]·2 DMSO·2 H2O (Ag4; DMSO=dimethyl sulfoxide, TBA=tetra-n-butylammonium), which was obtained by reaction of TBA4H4[γ-SiW10O 36] with AgOAc in an organic medium. Polyoxometalate Ag4 (see picture) selectively catalyzes hydrolytic oxidation of various silanes to the corresponding silanols in high yields (72-96 %). Copyright
- Kikukawa, Yuji,Kuroda, Yoshiyuki,Yamaguchi, Kazuya,Mizuno, Noritaka
-
supporting information; experimental part
p. 2434 - 2437
(2012/05/05)
-
- Catalytic oxidation of silanes by carbon nanotube-gold nanohybrids
-
Turning over silanes: The first nanotube-based catalytic system for silane oxidation is reported (see scheme). The reusable gold-nanotube hybrid cleanly oxidizes both alkyl and aryl silanes in high yields, under mild reaction conditions, and compares most favorably to any other catalytic system in terms of overall efficacy and turnover values. Copyright
- John, Jubi,Gravel, Edmond,Hagege, Agnes,Li, Haiyan,Gacoin, Thierry,Doris, Eric
-
supporting information; experimental part
p. 7533 - 7536
(2011/10/04)
-
- Diorganotelluride-catalyzed oxidation of silanes to silanols under atmospheric oxygen
-
Diorganotellurides efficiently catalyze the aerobic oxidation of organosilanes under photosensitized conditions to afford the corresponding silanols in excellent yield.
- Okada, Yasunori,Oba, Makoto,Arai, Atsushi,Tanaka, Kazuhito,Nishiyama, Kozaburo,Ando, Wataru
-
scheme or table
p. 383 - 385
(2010/04/28)
-
- Nonclassical ruthenium silyl dihydride complexes TpRu(PPh 3)(I?·3-HSiR3H) [Tp = hydridotris(pyrazolyl)borate]: Catalytic hydrolytic oxidation of organosilanes to silanols with TpRu(PPh3)(I?·3-HSiR 3H)
-
An X-ray crystallographic study showed that it is more appropriate to describe the complexes TpRu(PPh3)"H2SiR 3" as TpRu(PPh3)(I?·3- HSiR3H), a static structure containing HA?·A? ·A?·SiA?·A?·A?·H bonding rather than a highly fluxional pair ofI?-silane hydride species TpRu(PPh3)(Ha)(I?·2-H bSiR3) [rlhar2] TpRu(PPh3)(H b)(I?·2-HaSiR3). One of the complexes was used for the catalytic hydrolytic oxidation of organosilanes to silanols. A mechanism, which does not involve the usual oxidative addition of silane to the metal center to form the silyl hydride species, is proposed, which is supported by theoretical calculations.
- Lee, Ting Yan,Dang, Li,Zhou, Zhongyuan,Yeung, Chi Hung,Lin, Zhenyang,Lau, Chak Po
-
experimental part
p. 5675 - 5684
(2011/03/17)
-
- Tris(triorganosilyl)phosphites-New ligands controlling catalytic activity of Pt(0) complex in curing of silicone rubber
-
Applying novel and efficient method, new tris(triorganosilyl)phosphites were synthesized and further used for the preparation of new well-defined platinum complexes [Pt(DVTMDS)(P(OSiR3)3 )3}] (DVTMDS-(H2C-CHSiMe2)2O, R3-Si 7O9(1OCt)7, 1Pr 3, MePh2, Ph3, (OtBu)3, (OSiMe3)3) which were well characterized by spectroscopic methods. Structures of two platinum(O) complexes, [Pt{T|4(H 2C=CHSiMe2)2o}{P(OSiPh3) 3}] (10) and [Pt(η-(H2C=CHSiMe2) 2O}{P(OSi(OtBu3)3}] (11) were determined by X-ray analysis. The new complexes proved to be very effective catalysts of a crosslinking of silicones via hydrosilylation at elevated temperature with relatively short cure time and the enthalpy of network formation similar to that of Pt-Karstedt's/DAM (DAM - diallyl maleate) catalytic system. Additionally, the catalyzed silicone formulation had sufficiently long pot-life at room temperature.
- Kownacki, Ireneusz,Marciniec, Bogdan,Szubert, Karol,Kubicki, Maciej,Jankowska, Magdalena,Steinberger, Helmut,Rubinsztajn, Slawomir
-
experimental part
p. 105 - 112
(2011/10/09)
-
- Supported gold nanoparticle catalyst for the selective oxidation of silanes to silanols in water
-
Hydroxyapatite-supported gold nanoparticles (AuHAP) can act as highly efficient and reusable catalysts for the oxidation of diverse silanes into silanols in water; this is the first catalytic methodology for the selective synthesis of aliphatic silanols using water under organic-solvent-free conditions.
- Mitsudome, Takato,Noujima, Akifumi,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
-
supporting information; experimental part
p. 5302 - 5304
(2010/01/31)
-