29793-40-6Relevant academic research and scientific papers
Facile nucleophilic fluorination by synergistic effect between polymer-supported ionic liquid catalyst and tert-alcohol reaction media system
Kim, Dong Wook,Jeong, Hwan-Jeong,Lim, Seok Tae,Sohn, Myung-Hee,Chi, Dae Yoon
, p. 4209 - 4214 (2008)
A highly efficient method was developed for nucleophilic fluorination using an alkali metal fluoride through the synergistic effect of the polymer-supported ionic liquid (PSIL) as a catalyst and tert-alcohol as an alternative reaction media. This PSIL/tert-alcohol system not only enhances the reactivity of alkali metal fluorides and reduces the formation of by-products but also allows the use of a polymer-supported catalyst protocol. As an example, the nucleophilic fluorinations of the model compound, 2-(3-bromopropoxy)naphthalene, with CsF using only tert-amyl alcohol as solvent (for 2 h reaction time), 0.5 equiv of PS[hmim][BF4] in CH3CN (for 12 h reaction time), and 0.5 equiv of PS[hmim][BF4] in tert-amyl alcohol (which is a PSIL/tert-alcohol system for the synergistic effect; for 2 h reaction time) provided 18, 40, and 84% yield, respectively. The characteristics of the nucleophilic fluorination reactions of some halo- and alkanesulfonyloxyalkane systems to the corresponding fluoroalkanes using various alkali metal fluorides are also reported.
Tetrabutylammonium tetra(tert-butyl alcohol)-coordinated fluoride as a facile fluoride source
Kim, Dong Wook,Jeong, Hwan-Jeong,Lim, Seok Tae,Sohn, Myung-Hee
, p. 8404 - 8406 (2008)
(Figure Presented) F- on: The title compound TBAF(tBuOH) 4 can act as a highly effective fluoride source for nucleophilic fluorination thanks to its favorable properties, such as a stable structure (in which the fluoride ion is surrounded by four bulky nonpolar protic alcohol molecules), a dehydrated state, low hygroscopicity, good solubility in organic solvents, good nucleophilicity, and low basicity.
Bis-tert-Alcohol-Functionalized Crown-6-Calix[4]arene: An Organic Promoter for Nucleophilic Fluorination
Jadhav, Vinod H.,Choi, Wonsil,Lee, Sung-Sik,Lee, Sungyul,Kim, Dong Wook
, p. 4515 - 4520 (2016)
A bis-tert-alcohol-functionalized crown-6-calix[4]arene (BACCA) was designed and prepared as a multifunctional organic promoter for nucleophilic fluorinations with CsF. By formation of a CsF/BACCA complex, BACCA could release a significantly active and selective fluoride source for SN2 fluorination reactions. The origin of the promoting effects of BACCA was studied by quantum chemical methods. The role of BACCA was revealed to be separation of the metal fluoride to a large distance (>8 ?), thereby producing an essentially "free" F-. The synergistic actions of the crown-6-calix[4]arene subunit (whose O atoms coordinate the counter-cation Cs+) and the terminal tert-alcohol OH groups (forming controlled hydrogen bonds with F-) of BACCA led to tremendous efficiency in SN2 fluorination of base-sensitive substrates.
PtBr2-catalyzed transformation of allyl(o-ethynylaryl)carbinol derivatives into functionalized indenes. Formal sp3 C-H bond activation
Bajracharya, Gan B.,Pahadi, Nirmal K.,Gridnev, Ilya D.,Yamamoto, Yoshinori
, p. 6204 - 6210 (2006)
The PtBr2-catalyzed reaction of 1-ethynyl-2-(1-alkoxybut-3-enyl) benzenes at 120 °C in CH3CN gave functionalized indenes in good to allowable yields. Most probably, the hydrogen at the terminal alkyne is transferred to the adjacent internal β-carbon to form an (η2-vinylidene)platinum carbene intermediate, which activates the sp3 C-H bond at the benzylic carbon. This reaction pathway is supported by DFT calculations which suggest that the formation of the Pt-vinylidene complex is the rate-limiting stage for the whole transformation.
Synthesis, mechanism of formation, and catalytic activity of Xantphos nickel π-complexes
Staudaher, Nicholas D.,Stolley, Ryan M.,Louie, Janis
, p. 15577 - 15580 (2014)
A general synthetic route to the first Xantphos nickel alkyne and alkene complexes has been discovered. Various Ni π-complexes were prepared and characterized. NMR experiments indicate benzonitrile undergoes ligand exchange with a Xantphos ligand of (Xant)2Ni, a compound that was previously believed to be unreactive. The Ni π-complexes were also shown to be catalytically competent in cross coupling and cycloaddition reactions. (Xant)2Ni is also catalytically active for these reactions when activated by a nitrile or coordinating solvent. This journal is
“Conducted Tour” Migration of Li+ during the cis/trans Stereoinversion of α-Arylvinyllithiums
Knorr, Rudolf,Behringer, Claudia,Ruhdorfer, Jakob,von Roman, Ulrich,Lattke, Ernst,B?hrer, Petra
, p. 12861 - 12869 (2017)
A “conducted tour” migration keeps a mobile client on a profitable route even though an occasional side-step may seem attractive. A stereochemical manifestation of such a migration had been suggested by Donald J. Cram (1964), and we present now a different example that concerns the cis/trans stereoinversion of monomeric H2C=C(Li)-aryl compounds: Upon tetrahydrofuran (THF)-assisted heterolysis of the Li?C bond with formation of a solvent-separated ion pair (SSIP), the unchained “mobile client” Li+(THF)4 is proposed to surmount the rim of the electronically fixed aryl group and to disdain the less encumbered pathways across the H2C=C region. This interpretation is based on knowledge from a previously published series of monomeric α-arylalkenyllithiums in combination with two new members: 4-(α-lithiovinyl)-2,2-dimethylbenz[f]indane (1) revealed both a barrier against α-aryl rotation and a route-distinguishing retardation as compared with the corresponding migration-dependent cis/trans stereoinversion rate constant of 1-(α-lithiovinyl)naphthalene (2). Monomeric and dimeric ground states of 1 and 2 and their microsolvation numbers were determined by using the recently developed primary and secondary NMR criteria.
Tertiary arsine ligands for the Stille coupling reaction
Chishiro, Akane,Imoto, Hiroaki,Inaba, Ryoto,Konishi, Masafumi,Naka, Kensuke,Yumura, Takashi
, p. 95 - 103 (2021/12/27)
The Stille coupling reaction is one of the most important coupling reactions. It is well known that the triphenylarsine ligand can accelerate the reaction rate of Stille coupling. However, other arsine ligands have never been investigated for the Stille c
Indene formation upon borane-induced cyclization of arylallenes, 1,1-carboboration, and retro-hydroboration
Hasenbeck, Max,Wech, Felix,Averdunk, Arthur,Becker, Jonathan,Gellrich, Urs
supporting information, p. 5518 - 5521 (2021/06/12)
We herein report the reaction of arylallenes with tris(pentafluorophenyl)borane that yields pentafluorophenyl substituted indenes. The tris(pentafluorophenyl)borane induces the cyclization of the allene and transfers a pentafluorophenyl ring in the course of this reaction. A Hammett plot analysis and DFT computations indicate a 1,1-carboboration to be the C-C bond-forming step.
Method for preparing olefin compound under alkaline condition
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Paragraph 0021-0023, (2021/05/29)
The invention relates to a method for preparing an olefin compound under an alkaline condition. The method comprises the following steps: adding a solvent and an alkali catalyst into long-chain alcohol serving as a raw material, introducing sulfuryl fluoride gas, stirring for reaction, and separating and purifying to obtain the olefin compound. The olefin compound has a structural formula shown in the description; and in the formula, R is phenyl, substituted phenyl, heterocyclic aryl, fused ring aryl, substituted fused ring aryl or alkyl. An alkali-promoted alcohol-to-olefin conversion method developed by the invention is mild in reaction condition, simple and convenient to operate and low in instrument and equipment requirements, the long-chain alcohol is used as a reaction raw material, the price is low, the source is wide, and the yield of the prepared olefin compound is high; and the method effectively avoids the influence of acidic conditions on part of groups (acetal, ketal, epoxy and the like), is efficient in reaction and wide in substrate application range, can tolerate most of functional groups, and provides a new path for synthesis of complex olefins.
Nickel-Catalyzed Ligand-Free Hiyama Coupling of Aryl Bromides and Vinyltrimethoxysilane
Wei, Shichao,Mao, Yongjun,Shi, Shi-Liang
supporting information, p. 1670 - 1674 (2021/02/26)
We herein disclose the first Ni-catalyzed Hiyama coupling of aryl halides with vinylsilanes. This protocol uses cheap, nontoxic, and stable vinyltrimethoxysilane as the vinyl donor, proceeds under mild and ligand-free conditions, furnishing a diverse variety of styrene derivatives in high yields with excellent functional group compatibility.
