- Use of Silylated Formiates as Hydrosilane Equivalents
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The present invention relates to a method for preparing organic compounds of formula (I) by reaction between a silylated formiate of formula (II) and an organic compound in the presence of a catalyst and optionally of an additive. The invention also relates to use of the method for preparing organic compounds of formula (I) for the preparation of reagents for fine chemistry and for heavy chemistry, as well as in the production of vitamins, pharmaceutical products, adhesives, acrylic fibres, synthetic leathers, and pesticides.
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Paragraph 0514
(2021/09/26)
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- KF/clinoptilolite NPs: An efficient and heterogeneous catalyst for chemoselective silylation of alcohols and phenols
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Potassium fluoride incorporated on clinoptilolite nanoparticles (KF/CP NPs) by ion exchanging is found to be an effective and inexpensive heterogeneous nanocatalyst for chemoselective silylation of alcohols and phenols with 1,1,1,3,3,3-hexamethyldisilazane (HMDS) at room temperature. Nano-powder of clinoptilolite (CP) was prepared using a planetary ball mill mechanically method and characterized by dynamic light scattering (DLS), X-ray powder diffraction (XRD) and scanning electron microscope (SEM) analyses. Almost all of products were obtained in high yields as well as short reaction times and the catalyst was also reused eight times without loss of its catalytic activity.
- Oladee, Razieh,Zareyee, Daryoush,Khalilzadeh, Mohammad A.
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p. 731 - 737
(2021/03/31)
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- Silylation of Alcohols, Phenols, and Silanols with Alkynylsilanes – an Efficient Route to Silyl Ethers and Unsymmetrical Siloxanes
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The formation of several silyl ethers (alkoxysilanes, R3Si-OR') and unsymmetrical siloxanes (R3Si-O-SiR'3) can be catalyzed by the commercially available potassium bis(trimethylsilyl)amide (KHMDS). The reaction proceeds via direct dealkynative coupling between various alcohols or silanols and alkynylsilanes, with a simultaneous formation of gaseous acetylene as the sole by-product. The dehydrogenative and dealkenative coupling of alcohols or silanols are well-investigated, whilst the utilization of alkynylsilanes as silylating agents has never been comprehensively studied in this context. Overall, the presented system allows the synthesis of various attractive organosilicon compounds under mild conditions, making this approach an atom-efficient, environmentally benign, and sustainable alternative to existing synthetic solutions.
- Kuciński, Krzysztof,Stachowiak, Hanna,Hreczycho, Grzegorz
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p. 4042 - 4049
(2020/07/04)
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- Preparation method of hydroxyphenylboronic acid
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The invention discloses a preparation method of hydroxyphenylboronic acid, which belongs to the technical field of boric acid synthesis in medical intermediates. The method comprises the following steps: starting from bromophenol, carrying out BOC, trimethylsilyl or benzyl protection, forming a Grignard reagent, reacting with borate, or carrying out one-pot reaction with borate and n-butyllithium,and hydrolyzing to obtain hydroxyphenylboronic acid. According to the invention, cheap and easily available protecting groups are adopted, so that the protecting groups are easy to remove during boronation reaction hydrolysis, industrial amplification is easy to realize, batch production is carried out on the scale of dozens of kilograms, and the process stability is good.
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Paragraph 0034-0036; 0038-0040
(2020/05/08)
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- Preparation method of 4-(4-hydroxyphenyl) cyclohexanone
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The invention relates to the technical field of chemical synthesis, in particular to a preparation method of 4-(4-hydroxyphenyl) cyclohexanone. According to the preparation method, p-bromophenol is used as a raw material, a Grignard reagent is prepared through hydroxyl protection and Grignard reaction, then the prepared Grignard reagent is utilized to couple with 1,4-cyclohexanedione monoethyleneglycol ketal, then the product is dehydrated to obtain alkene, and double protecting groups are removed after hydrogenation to prepare a target product, namely, 4-(4-hydroxyphenyl) cyclohexanone. Thepreparation method of 4-(4-hydroxyphenyl) cyclohexanone, provided by the invention, has the advantages of reasonable process design, high yield and low production cost; the prepared 4-(4-hydroxyphenyl) cyclohexanone is a white solid, the HPLC content is more than 99.5%, the total yield of the product can reach 75-80%, and the raw materials are easy to obtain; and the method has simple operation and high safety, and realizes industrial production of 4-(4-hydroxyphenyl) cyclohexanone.
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Paragraph 0059-0061
(2019/08/01)
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- Iron-Catalyzed Silylation of Alcohols by Transfer Hydrosilylation with Silyl Formates
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An iron catalyst is shown for the first time to promote transfer hydrosilylation with silyl formates and is utilized for the silylation of alcohols. Attractive features of this protocol include the use of an earth-abundant transition-metal catalyst, mild reaction conditions, and the release of gases as the only byproducts (H 2 and CO 2).
- Godou, Timothé,Chauvier, Clément,Thuéry, Pierre,Cantat, Thibault
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supporting information
p. 2473 - 2477
(2017/10/26)
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- Silylation of O-H bonds by catalytic dehydrogenative and decarboxylative coupling of alcohols with silyl formates
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The silylation of O-H bonds is a useful methodology in organic synthesis and materials science. While this transformation is commonly achieved by reacting alcohols with reactive chlorosilanes or hydrosilanes, we show herein for the first time that silylformates HCO2SiR3 are efficient silylating agents for alcohols, in the presence of a ruthenium molecular catalyst.
- Chauvier, Clément,Godou, Timothé,Cantat, Thibault
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supporting information
p. 11697 - 11700
(2017/11/03)
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- Magnetic nanoparticle-supported DABCO tribromide: A versatile nanocatalyst for the synthesis of quinazolinones and benzimidazoles and protection/deprotection of hydroxyl groups
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1,4-Diazabicyclo[2.2.2]octane tribromide supported on magnetic Fe3O4 nanoparticles (MNPs-DABCO tribromide) as a novel heterogeneous tribromide type compound was found to be an efficient and reusable nanocatalyst for the one-pot synthesis of 2-arylquinazolin-4(3H)-ones and 2-aryl-1H-benzo[d]imidazoles through oxidative cyclization of aldehydes with 2-aminobenzamides and 1,2-phenylenediamine, respectively. Also, MNPs-DABCO tribromide catalyzed trimethylsilylation/tetrahydropyranylation and desilylation/depyranylation of a wide variety of alcohols and phenols through changing the solvent medium at room temperature.
- Rostami, Amin,Pourshiani, Omid,Navasi, Yahya,Darvishi, Neda,Saadati, Shaghayegh
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p. 9033 - 9040
(2017/08/29)
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- Highly atom economical uncatalysed and I2-catalysed silylation of phenols, alcohols and carbohydrates, using HMDS under solvent-free reaction conditions (SFRC)
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An uncatalysed silylation of phenols, regardless on the aggregate state and nature of the substituents with 0.55 equiv of HMDS under solvent-free reaction conditions (SFRC) at room temperature is reported. Sterically hindered phenols, carbohydrates and most of the alcohols additionally required a catalytic amount (up to 2 mol %) of iodine. The reaction protocol is very simple; obtaining a pure product, particularly of uncatalysed reactions, was frequently a completely solvent-free process.
- Jereb, Marjan
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experimental part
p. 3861 - 3867
(2012/06/30)
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- Nickel-catalyzed cross-coupling of aryl bromides with tertiary grignard reagents utilizing donor-functionalized N-heterocyclic carbenes (NHCs)
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Metal-catalyzed cross-coupling reactions are among the most important transformations in organic synthesis, allowing the efficient construction of complex structures from simpler, readily available building blocks.Many applications in large and small-scale synthesis can be found in different areas such as agrochemicals, pharmaceuticals and supramolecular chemistry. Whereas the coupling of sp2-hybridized carbon atoms in either reaction partner is well established, the use of CACHTUNGTRENUNG(sp3)-hybridized substrates presents some challenges. Catalytic cross-coupling of sterically hindered tertiary alkyl substrates is especially difficult, generally resulting in low yields, and thus, only few reports exist.[27] A big challenge in this field is not only to get the required level of reactivity, but also to overcome competing pathways like β-hydride elimination, hydrodehalogenation or isomerization
- Lohre, Claudia,Droege, Thomas,Wang, Congyang,Glorius, Frank
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supporting information; experimental part
p. 6052 - 6055
(2011/06/25)
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- A generic small-molecule microarray immobilization strategy
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Small-molecule microarrays are often limited by the requirement for each compound undergoing immobilization to contain a common functional group or by the need to prepare glass slides containing photo-reactive groups. Herein, we present a generic strategy
- Valls-Miret, Mariona,Bradley, Mark
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scheme or table
p. 6819 - 6822
(2012/01/02)
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- Protection of hydroxyl groups as a trimethylsilyl ether by 1,1,1,3,3,3-hexamethyldisilazane promoted by aspartic acid as an efficient organocatalyst
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A wide variety of alcohols and phenols were protected as trimethylsilyl ethers using 1,1,1,3,3,3-hexamethyl disilazane catalyzed by aspartic acid as a non-toxic, metal-free, and green organocatalyst at room temperature in acetonitrile under mild and heterogeneous conditions. The procedure is operationally simple and the silylated product was obtained in high yield and purity.
- Ghorbani-Choghamarani, Arash,Norouzi, Masoomeh
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scheme or table
p. 595 - 598
(2012/01/06)
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- Cross-linked poly(4-vinylpyridine/styrene) copolymer-supported bismuth(III) triflate: An efficient heterogeneous catalyst for silylation of alcohols and phenols with HMDS
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Cross-linked poly(4-vinylpyridine/styrene) copolymer-supported bismuth(III) triflate (30P/S-Bi) effectively activates hexamethyldisilazane (HMDS) for the silylation of alcohols and phenols. By the use of this heterogeneous catalytic system, a wide range of alcohols as well as phenols are converted into their corresponding trimethylsilyl ethers in high yield under mild reaction conditions. The catalyst was reused more than 10 times without significant loss of its catalytic activity.
- Lee, Sang-Hyeup,Kadam, Santosh T.
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experimental part
p. 608 - 615
(2011/11/12)
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- Rapid and efficient trimethylsilyl protection of hydroxyl groups catalyzed by niobium(V) chloride
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An efficient and convenient procedure for the trimethylsilylation of a wide variety of alcohols, including primary, benzylic, secondary, and phenols with hexamethyldisilazane, has been developed. The reactions were carried out at room temperature in the presence of a catalytic amount of niobium(V) chloride and afforded the corresponding trimethylsilyl ethers in high to excellent yields in short time. Copyright Taylor & Francis Group, LLC.
- Hou, Jun-Tao,Chen, Hong-Li,Zhang, Zhan-Hui
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experimental part
p. 88 - 93
(2011/04/22)
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- Green and efficient procedure for the trimethylsilylation of hydroxy groups and their regeneration using sulfamic acid as recyclable catalyst
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Structurally diverse alcohols and phenols were efficiently transformed into their corresponding trimethylsilyl ethers with hexamethyldisilazane (HMDS) in the presence of catalytic amounts of sulfamic acid (SA) at room temperature under both acetonitrile and solvent-free conditions. Deprotection of these trimethylsilyl ethers to their parent alcohols and phenols was also achieved using this catalyst in water at room temperature. Copyright Taylor & Francis Group, LLC.
- Rostami, Amin,Ahmad-Jangi, Firoz,Zarebin, Mohammad Rezgar,Akradi, Jamal
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experimental part
p. 1500 - 1507
(2010/07/15)
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- Iron(III) trifluoroacetate [Fe(F3CCO2)3] as an easily available, non-hygroscopic, non-corrosive, highly stable and a reusable Lewis Acid catalyst: Efficient O-silylation of α-hydroxyphosphonates, alcohols and phenols by he
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O-Silylation of hydroxyl groups of α-hydroxyphosphonates, primary, secondary tertiary-alcohols and phenols with HMDS was achieved in high to excellent yields using iron(III) trifluoroacetate [Fe(F3CCO2)3] as an easily avai
- Firouzabadi, Habib,Iranpoor, Nasser,Jafari, Abbas Ali,Jafari, Mohammad Reza
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p. 2711 - 2714
(2008/12/20)
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- Rapid and highly efficient trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) catalyzed by reusable zirconyl triflate, [ZrO(OTf)2]
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In this paper, rapid and efficient trimethylsilylation of alcohols and phenols with hexamethyldisilazane in the presence of catalytic amounts of ZrO(OTf)2 is reported. Primary, secondary and tertiary alcohols as well as phenols were efficiently converted to their corresponding TMS ethers in short reaction times at room temperature. It is noteworthy that this method can be used for chemoselective silylation of primary alcohols in the presence of secondary and tertiary alcohols and phenols.
- Moghadam, Majid,Tangestaninejad, Shahram,Mirkhani, Valiollah,Mohammadpoor-Baltork, Iraj,Chahardahcheric, Shahin,Tavakoli, Ziba
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p. 2041 - 2046
(2008/09/19)
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- Simple and practical protocol for the silylation of phenol derivatives using reusable NaHSO4 dispread on silica gel under neutral conditions
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A simple and mild procedure for the trimethylsilylation of a wide variety of phenols with hexamethyldisilazane (HMDS) on the surface of silica gel dispersed with NaHSO4 at r.t. in a few minutes with excellent yields under neutral conditions is
- Khalili, Mahideh S.,Ghafuri, Hossein,Mojahedi-Jahromi, Samaneh,Hashemi, Mohammed M.
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p. 175 - 179
(2007/10/03)
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- Silica sulfuric acid as a reusable catalyst for efficient and simple silylation of hydroxyl groups using hexamethyldisilazane (HMDS)
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At room temperature, alcohols and phenols are efficiently protected with hexamethyldisilazane (HMDS) in the presence of silica sulfuric acid in good to excellent yields. The catalyst can be recycled for subsequent reactions without any appreciable loss of efficiency. Copyright Taylor and Francis Group, LLC.
- Ghafuri, Hossein,Eftekhari-Sis, Bagher,Hashemi, Mohammed M.
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p. 1645 - 1651
(2008/02/08)
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- A novel and highly efficient method for the silylation of alcohols with hexamethyldisilazane (HMDS) catalyzed by recyclable sulfonic acid-functionalized ordered nanoporous silica
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Silylation of alcohols with hexamethyldisilazane (HMDS) in dichloromethane provides the corresponding silyl ethers in almost quantitative yields at room temperature using 1-3 mol % of sulfonic acid-functionalized silica. Additionally, the catalyst display
- Zareyee, Daryoush,Karimi, Babak
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p. 1277 - 1280
(2007/10/03)
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- Efficient and convenient procedure for protection of hydroxyl groups to the THP, THF and TMS ethers and oxidation of these ethers to their aldehydes or ketones in [BPy]FeCl4 as a low cost room temperature ionic liquid
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Alcohols were converted to the corresponding THP, THF or TMS ethers in high to excellent yields in 1-n-butylpyridinium chloroferrate media as a stable and low cost room temperature ionic liquid. In addition, oxidation of these ethers to their aldehydes or ketones without any overoxidation reactions in this ionic liquid was also performed.
- Khosropour, Ahmad R.,Khodaei, Mohammad M.,Ghaderi, Sattar
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p. 326 - 330
(2007/10/03)
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- Non-cluster type bismuth compounds
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PCT No. PCT/GB96/00183 Sec. 371 Date Oct. 22, 1997 Sec. 102(e) Date Oct. 22, 1997 PCT Filed Jan. 26, 1996 PCT Pub. No. WO96/22994 PCT Pub. Date Aug. 1, 1996A method of generating an image of a human or non-human animal body which comprises administering t
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- New bisphenols with silylene fragments: Synthesis and spectra
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A series of bisphenols containing silylene sequences were prepared by condensation of 4-(trimethylsiloxy)phenylmagnesium bromide with αω-dichloropermethylsilanes and studied by fluorescence spectroscopy.
- Pushkarev
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p. 1749 - 1751
(2007/10/03)
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- Carbofunctional silacyclobutanes 1. Synthesis of 1-(ω-hydroxyalkyl)silacyclobutanes
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A four-step synthesis of 1-(ω-hydroxyalkyl)- and 1-(4-hydroxyphenyl)silacyclobutanes was carried out. The influence of the structure of the initial compounds and the reaction conditions on the ratio of the reaction products formed was studied. The stabili
- Ushakov,Fedorova
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p. 901 - 910
(2007/10/03)
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- TRIMETHYLSILYL TRICHLOROACETATE: A NEW REAGENT FOR SALT-FREE SILYLATIONS
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Trimethylsylil trichloroacetate (1) is a convenient reagent for the silylation of phenols, carboxylic acids, mercaptans, amides, acetylenes, and β-keto esters, while the reaction of 1 with aldehydes and ketones affords silylated trichloromethyl carbinols (5).
- Renga, James M.,Pen-Chung, Wang
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p. 1175 - 1178
(2007/10/02)
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