- Nickel-catalysed anti-Markovnikov hydroarylation of unactivated alkenes with unactivated arenes facilitated by non-covalent interactions
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Anti-Markovnikov additions to alkenes have been a longstanding goal of catalysis, and anti-Markovnikov addition of arenes to alkenes would produce alkylarenes that are distinct from those formed by acid-catalysed processes. Existing hydroarylations are either directed or occur with low reactivity and low regioselectivity for the n-alkylarene. Herein, we report the first undirected hydroarylation of unactivated alkenes with unactivated arenes that occurs with high regioselectivity for the anti-Markovnikov product. The reaction occurs with a nickel catalyst ligated by a highly sterically hindered N-heterocyclic carbene. Catalytically relevant arene- and alkene-bound nickel complexes have been characterized, and the rate-limiting step was shown to be reductive elimination to form the C–C bond. Density functional theory calculations, combined with second-generation absolutely localized molecular orbital energy decomposition analysis, suggest that the difference in activity between catalysts containing large and small carbenes results more from stabilizing intramolecular non-covalent interactions in the secondary coordination sphere than from steric hindrance.
- Hartwig, John F.,Nakao, Yoshiaki,Ohgi, Akito,Saper, Noam I.,Semba, Kazuhiko,Small, David W.
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Read Online
- Photoinduced Charge-Transfer State of 4-Carbazolyl-3-(trifluoromethyl)benzoic Acid: Photophysical Property and Application to Reduction of Carbon?Halogen Bonds as a Sensitizer
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The photoinduced persistent intramolecular charge-transfer state of 4-carbazolyl-3-(trifluoromethyl)benzoic acid was confirmed. It showed a higher catalytic activity in terms of yield and selectivity in the photochemical reduction of alkyl halides compared to the parent carbazole. Even unactivated primary alkyl bromides could be reduced by this photocatalyst. The high catalytic activity is rationalized by considering the slower backward single-electron transfer owing to the spatial separation of the donor and acceptor subunits.
- Matsubara, Ryosuke,Shimada, Toshiyuki,Kobori, Yasuhiro,Yabuta, Tatsushi,Osakai, Toshiyuki,Hayashi, Masahiko
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Read Online
- A catalytic C-C bond-forming reaction between aliphatic fluorohydrocarbons and arylsilanes
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C-C coupling reactions between arylsilanes and alkylfluorides are efficiently catalyzed by disilyl cation 1. Primary as well as secondary alkylfluorides were quantitatively coupled with arylsilanes; however, in the case of tertiary fluorides, the hydrodef
- Luehmann, Nicole,Panisch, Robin,Mueller, Thomas
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Read Online
- A CONVENIENT REDUCTION OF DIALKYLATED TOSYLMETHYL ISOCYANIDE
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Dialkylated tosylmethyl isocyanides have been conveniently reduced to the corresponding hydrocarbons with lithium in liquid ammonia.This process has been succesfully utilised in the synthesis of (Z)-9-tricosene - a sex pheromone of common house fly.
- Yadav, J. S.,Reddy, P. Satyanarayana
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Read Online
- Hexadecane Conversion on an Alumina–Nickel Catalyst
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Abstract: The conversion of hexadecane on a 4% Ni/Al2O3 catalyst in a temperature range of 20–300°C was studied using IR spectroscopy and catalytic methods. It was found that the dehydrogenation of hexadecane occurred at 20–100°C with the subsequent formation of aromatic products, but the rates of these processes were very low. As the reaction temperature was increased to 200°C, the 4% Ni/Al2O3 catalyst exhibited a maximum activity and high selectivity for the formation of 1-hexadecene, and aromatic compounds and cracking products were present in the reaction products. As the reaction temperature was further increased, the catalytic activity significantly decreased. This was due to the fact that polyaromatic deposits gradually accumulated on the catalyst surface in a temperature range of 200–300°C.
- Chesnokov,Chichkan,Paukshtis,Chesalov, Yu. A.,Krasnov
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p. 439 - 445
(2019/09/04)
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- Involving Single-Atom Silver(0) in Selective Dehalogenation by AgF under Visible-Light Irradiation
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The dehalogenation-arylation and the hydrodehalogenation of various types of organic halides are selectively realized using AgF and visible light without any organic additives under mild conditions. Single-atom silver(0) (denoted as SAAg) serves as the catalytically active center, and the TOF of SAAg reaches 6000 h-1. This elusive activity of Ag is beyond that expected from its ionic, nano, or bulk forms.
- Wu, Wenli,Cui, Enxin,Zhang, Yun,Zhang, Chen,Zhu, Feng,Tung, Chen-Ho,Wang, Yifeng
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p. 6335 - 6341
(2019/07/04)
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- Cross-Coupling Reactions of Alkyl Halides with Aryl Grignard Reagents Using a Tetrachloroferrate with an Innocent Countercation
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Bis(triphenylphosphoranylidene)ammonium tetrachloroferrate, (PPN)[FeCl4] (1), was evaluated as a catalyst for cross-coupling reactions. 1 exhibits high stability toward air and moisture and is an effective catalyst for the reaction of secondary alkyl halides with aryl Grignard reagents. The PPN cation is considered as an innocent counterpart to the iron center. We have developed an easy-to-handle iron catalyst for “ligand-free” cross-coupling reactions. (Figure presented.).
- Hashimoto, Toru,Maruyama, Tsubasa,Yamaguchi, Takamichi,Matsubara, Yutaka,Yamaguchi, Yoshitaka
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supporting information
p. 4232 - 4236
(2019/08/16)
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- Terminal C(sp3)–H alkylation of internal alkenes via Ni/H-catalyzed isomerization
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An efficient nickel-catalyzed reductive relay cross-coupling of internal alkenes with alkyl (or aryl) halides has been developed. This method has demonstrated broad substrate scope, mild reaction conditions and excellent terminal-selectivity. Moreover, th
- Wang, Zhen-Yu,Wan, Jia-Hao,Wang, Gao-Yin,Wang, Rui,Jin, Ruo-Xing,Lan, Quan,Wang, Xi-Sheng
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supporting information
p. 2302 - 2305
(2018/05/16)
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- Cross-coupling reaction of alkyl halides with alkyl grignard reagents catalyzed by cp-iron complexes in the presence of 1,3-butadiene
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Iron-catalyzed cross-coupling reaction of alkyl halides with alkyl Grignard reagents by the combined use of cyclopentadienyl ligand and 1,3-butadiene additive is described. The reaction smoothly proceeds at room temperature using unactivated alkyl bromides and fluorides via non-radical mechanism, which is in sharp contrast with hitherto known Fe-catalyzed cross-coupling reactions of alkyl halides.
- Iwasaki, Takanori,Shimizu, Ryohei,Imanishi, Reiko,Kuniyasu, Hitoshi,Kambe, Nobuaki
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supporting information
p. 763 - 766
(2018/05/29)
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- Alkyl diphenyl phosphine and preparing alkyl diphenyl phosphine payment proportional to production alkyl benzene
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The invention discloses alkyl diphenylphosphine and a method for preparing alkyl diphenylphosphine with co-production of alkylbenzene. The structural formula of alkyl diphenylphosphine is shown in a formula I. The method comprises: adding triphenylphosphine and metal lithium into an organic solvent for reaction for 3-6 hours at room temperature; and cooling the reaction system to 0-10 DEG C, adding halogenated straight-chain alkane for insulating reaction, then raising the temperature of the system to 30-80 DEG C, keeping the temperature to react for 1-3 hours, removing the organic solvent and reducing the pressure and distilling to separately obtain alkyl diphenylphosphine and alkylbenzene. According to the alkyl diphenylphosphine disclosed by the invention, alkyl is directly bonded with P, so that the alkyl diphenylphosphine can be dissolved in most solvents and can be used as a ligand for homogeneous catalysts. By virtue of the method disclosed by the invention, high value straight-chain alkylbenzene is co-produced while straight-chain alkyl diphenylphosphine is prepared by way of a one-pot process. Use of chloro-tert-butane which is relatively high in price and waste of the metal lithium are avoided. The method is simple to operate, efficient, low in energy consumption, low in cost and suitable for large-scaled industrial production.
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Paragraph 0067; 0070-0073
(2017/08/25)
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- With machine phosphine molybdenum complex, preparation method and application
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The invention discloses an organic phosphonium molybdenum complex, a preparation method and application. The organic phosphonium molybdenum complex has the following general formula: Mo[P(Ph)2R]2Cl5, wherein the P(Ph)2R is alkyldiphenylphosphine; the R is linear-chain alkyl with the carbon atom number of 3-10. According to the organic phosphonium molybdenum complex provided by the invention, alkyldiphenylphosphine is adopted as the ligand, and the organic phosphonium molybdenum complex can be dissolved in dicyclopentadiene, and can form a homogeneous system with dicyclopentadiene when used as a main catalyst to catalyze dicyclopentadiene for ring opening polymerization, so that the catalytic efficiency is greatly improved, and the production efficiency of polydicyclopentadiene is improved; the organic phosphonium molybdenum complex is relatively high in catalytic activity, and the polydicyclopentadiene product prepared through adopting the organic phosphonium molybdenum complex as the main catalyst is high in quality and excellent in the mechanical properties, such as, tensile strength and impact strength; the organic phosphonium molybdenum complex is relatively high in chemical stability, insensitive to air and moisture, simple in preparation, low in cost and suitable for popularization and application.
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Paragraph 0071; 0078-0080
(2017/08/31)
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- Metathesis of renewable polyene feedstocks – Indirect evidences of the formation of catalytically active ruthenium allylidene species
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Cross-metathesis (CM) of conjugated polyenes, such as 1,6-diphenyl-1,3,5-hexatriene (1) and α-eleostearic acid methyl ester (2) with several olefins, including 1-hexene, dimethyl maleate and cis-stilbene as model compounds has been carried out using (1,3-bis-(2,4,6-trimethylphenyl)-2-imidazolidinylidene)-dichloro(o-isopropoxyphenylmethylene)ruthenium (Hoveyda-Grubbs 2nd generation, HG2) catalyst. The feasibility of these reactions is demonstrated by the observed high conversions and reasonable yields. Thus, regardless of the relatively low electron density, =CH–CH= conjugated units of molecules, including compound 2 as a sustainable, non-foodstuff source, can be utilized as building blocks for the synthesis of various value-added chemicals via olefin metathesis. DFT-studies and the product spectrum of the self-metathesis of 1,6-diphenyl-1,3,5-hexatriene suggest that a Ru η1-allylidene complex is the active species in the reaction.
- Kovács, Ervin,Sághy, Péter,Turczel, Gábor,Tóth, Imre,Lendvay, Gy?rgy,Domján, Attila,Anastas, Paul T.,Tuba, Róbert
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supporting information
p. 213 - 217
(2017/09/12)
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- Efficient phosphine-mediated formal C(sp3)-C(sp3) coupling reactions of alkyl halides in batch and flow
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The construction of C(sp3)-C(sp3) bond is an essential chemical transformation in synthetic chemistry due to its abundance in organic scaffolds. Here we demonstrate a valuable adaptation of the Wittig-type chemical procedure to efficiently facilitate C(sp3)-C(sp3) bond formation utilizing a range of alkyl building blocks. Additionally the method is amenable with flow synthesis to afford coupled products in good to excellent yields without laborious purification process.
- Tran,Hock,Gordon,Koenigs,Nguyen
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supporting information
p. 4950 - 4953
(2017/07/11)
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- Bisphosphine compd., and Bisphosphine compound and a transition metal catalyst, and method of manufacturing the same (by machine translation)
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PROBLEM TO BE SOLVED: To provide a bisphosphine compound with a new bidentate phosphine ligand having a highly bulky substituent group on a phosphorus atom, which enables highly efficient and highly selective progress in various organic synthesis reactions, especially, cross coupling reaction, and a transition metal catalyst using the bisphosphine compound as a ligand, and a method for manufacturing them.SOLUTION: There are provided a bisphosphine compound represented by general formula (A) or general formula (B) and a transition metal catalyst using the bisphosphine compound as a ligand, and a method for manufacturing them.
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Paragraph 0562; 0569; 0570
(2016/11/17)
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- Single-Electron-Transfer-Induced Coupling of Alkylzinc Reagents with Aryl Iodides
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Alkylzinc reagents prepared from an alkyllithium and zinc iodide were found to undergo coupling with aryl and alkenyl iodides in the presence of LiI in a mixed solvent consisting of THF and diglyme (1:1). Alkyllithiums, prepared by halogen–lithium exchange between an alkyl iodide and tert-butyllithium, are also converted to alkylarenes through alkylzinc reagents.
- Okura, Keisho,Shirakawa, Eiji
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supporting information
p. 3043 - 3046
(2016/07/14)
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- From Dimethylamine to Pyrrolidine: The Development of an Improved Nickel Pincer Complex for Cross-Coupling of Nonactivated Secondary Alkyl Halides
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Replacement of a dimethyl amino group of the amidobis(amine) nickel(II) pincer complex (1), [(MeN2N)Ni-Cl], by a pyrrolidino group resulted in a new nickel(II) pincer complex (2), [(PyrNMeNN)Ni-Cl]. Complex 2 is an efficient catalyst for Kumada and Suzuki-Miyaura cross-coupling of nonactivated secondary alkyl halides, while complex 1 is largely inactive. The significant activity difference is tentatively attributed to a minimal structural difference, which leads to a more hemilabile ligand.
- Perez Garcia, Pablo M.,Di Franco, Thomas,Epenoy, Alexandre,Scopelliti, Rosario,Hu, Xile
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p. 258 - 261
(2016/01/12)
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- Nickel-catalyzed alkylative cross-coupling of anisoles with grignard reagents via C-O bond activation
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We report nickel-catalyzed cross-coupling of methoxyarenes with alkylmagnesium halides, in which a methoxy group is eliminated. A wide range of alkyl groups, including those bearing β-hydrogens, can be introduced directly at the ipso position of anisole derivatives. We demonstrate that the robustness of a methoxy group allows this alkylation protocol to be used to synthesize elaborate molecules by combining it with traditional cross-coupling reactions or oxidative transformation. The success of this method is dependent on the use of alkylmagnesium iodides, but not chlorides or bromides, which highlights the importance of the halide used in developing catalytic reactions using Grignard reagents.
- Tobisu, Mamoru,Takahira, Tsuyoshi,Morioka, Toshifumi,Chatani, Naoto
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supporting information
p. 6711 - 6714
(2016/06/14)
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- Copper-Catalyzed Regioselective Hydroalkylation of 1,3-Dienes with Alkyl Fluorides and Grignard Reagents
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Copper complexes generated in situ from CuCl2, alkyl Grignard reagents, and 1,3-dienes play important roles as catalytic active species for the 1,2-hydroalkylation of 1,3-dienes by alkyl fluorides through C-F bond cleavage. The alkyl group is introduced to an internal carbon atom of the 1,3-diene regioselectively, thus giving rise to the branched terminal alkene product. Making the switch: A copper-hydride species, generated by the treatment of a copper salt with alkyl Grignard reagents, catalyzes the 1,2-hydroalkylation of 1,3-dienes by alkyl fluorides and Grignard reagents. The alkyl group of the alkyl fluoride is selectively introduced to an internal carbon atom of the 1,3-diene and the Grignard reagent acts as hydride source to give the branched terminal alkene, even in the presence of alkenes and alkynes.
- Iwasaki, Takanori,Shimizu, Ryohei,Imanishi, Reiko,Kuniyasu, Hitoshi,Kambe, Nobuaki
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supporting information
p. 9347 - 9350
(2015/08/06)
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- Organometallic nickel(III) complexes relevant to cross-coupling and carbon-heteroatom bond formation reactions
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Nickel complexes have been widely employed as catalysts in C-C and C-heteroatom bond formation reactions. In addition to Ni(0) and Ni(II) intermediates, several Ni-catalyzed reactions are proposed to also involve odd-electron Ni(I) and Ni(III) oxidation states. We report herein the isolation, structural and spectroscopic characterization, and organometallic reactivity of Ni(III) complexes containing aryl and alkyl ligands. These Ni(III) species undergo transmetalation and/or reductive elimination reactions to form new C-C or C-heteroatom bonds and are also competent catalysts for Kumada and Negishi cross-coupling reactions. Overall, these results provide strong evidence for the direct involvement of organometallic Ni(III) species in cross-coupling reactions and oxidatively induced C-heteroatom bond formation reactions.
- Zheng, Bo,Tang, Fengzhi,Luo, Jia,Schultz, Jason W.,Rath, Nigam P.,Mirica, Liviu M.
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supporting information
p. 6499 - 6504
(2014/05/20)
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- Iron-catalyzed cross-coupling of unactivated secondary alkyl thio ethers and sulfones with aryl grignard reagents
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The first systematic investigation of unactivated aliphatic sulfur compounds as electrophiles in transition-metal-catalyzed cross-coupling are described. Initial studies focused on discerning the structural and electronic features of the organosulfur substrate that enable the challenging oxidative addition to the C(sp3)-S bond. Through extensive optimization efforts, an Fe(acac)3-catalyzed cross-coupling of unactivated alkyl aryl thio ethers with aryl Grignard reagents was realized in which a nitrogen "directing group" on the S-aryl moiety of the thio ether served a critical role in facilitating the oxidative addition step. In addition, alkyl phenyl sulfones were found to be effective electrophiles in the Fe(acac) 3-catalyzed cross-coupling with aryl Grignard reagents. For the latter class of electrophile, a thorough assessment of the various reaction parameters revealed a dramatic enhancement in reaction efficiency with an excess of TMEDA (8.0 equiv). The optimized reaction protocol was used to evaluate the scope of the method with respect to both the organomagnesium nucleophile and sulfone electrophile.
- Denmark, Scott E.,Cresswell, Alexander J.
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supporting information
p. 12593 - 12628
(2014/01/17)
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- Silylium ion/phosphane lewis pairs
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The reactivity of a series of silylium ion/phosphane Lewis pairs was studied. Triarylsilylium borates 4[B(C6F5)4] form frustrated Lewis pairs (FLPs) of moderate stability with sterically hindered phosphanes 2. Some of these FLPs are able to cleave dihydrogen under ambient conditions. The combination of bulky trialkylphosphanes with triarylsilylium ions can be used to sequester CO2 in the form of silylacylphosphonium ions 12. The ability to activate molecular hydrogen by reaction of silylium ion/phosphane Lewis pairs is dominated by thermodynamic and steric factors. For a given silylium ion increasing proton affinity and increasing steric hindrance of the phosphane proved to be beneficial. Nevertheless, excessive steric hindrance leads to a breakdown of the dihydrogen-splitting activity of a silylium/phosphane Lewis pair.
- Reissmann, Matti,Schaefer, Andre,Jung, Sebastian,Mueller, Thomas
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p. 6736 - 6744
(2014/01/06)
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- Olefin-assisted iron-catalyzed alkylation of aryl chlorides
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A selective and operationally simple ironcatalyzed cross-coupling of aryl chlorides with alkylmagnesium halides has been developed. The reaction tolerates various functional groups and exhibits high chemoselectivity even in the presence of aryl bromides. Mechanistic studies indicate the essential role of the olefin substituent for substrate activation. Competing polymerization and reduction are effectively suppressed.
- Guelak, Samet,Gieshoff, Tim N.,Von Wangelin, Axel Jacobi
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p. 2197 - 2202
(2013/10/01)
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- Oxidative coupling reactions of grignard reagents with nitrous oxide
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Catalysis with laughing gas: N2O in combination with transition-metal catalysts allow the oxidative homo- and cross-coupling of Grignard reagents. The reactions can be performed under mild conditions despite the inert character of N2O. Copyright
- Kiefer, Gregor,Jeanbourquin, Loic,Severin, Kay
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supporting information
p. 6302 - 6305
(2013/07/19)
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- Cross-coupling of alkyl halides with aryl or alkyl Grignards catalyzed by dinuclear Ni(ii) complexes containing functionalized tripodal amine-pyrazolyl ligands
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Structurally distinctive dinuclear Ni(ii) complexes with furan or thiophene tethered amine-pyrazolyl tripodal hybrid ligands have been synthesized and crystallographically characterized. All complexes are catalytically active towards cross-coupling of aryl/alkyl Grignard reagents with β-H containing alkyl halides at room temperature in the presence of N,N,N',N'- tetramethylethylenediamine (TMEDA). The catalytic efficacy of the complexes is dependent on the tether substituent at the central amine. Two species, Ni(ii) TMEDA and Mg(ii) TMEDA complexes, have been isolated from the catalytic reaction mixtures under different conditions. Some ligand-stabilized Ni(ii) and Mg(ii) bimetallic species have also been identified in the ESI-MS spectra.
- Xue, Fei,Zhao, Jin,Hor, T. S. Andy
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p. 5150 - 5158
(2013/04/10)
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- Stabilization of long-chain intermediates in solution. octyl radicals and cations
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The rearrangements of 1-octyl, 1-decyl and 1-tridecyl intermediates obtained from thermal lead(IV) acetate (LTA) decarboxylation of nonanoic, undecanoic and tetradecanoic acid were investigated experimentally through analysis and distribution of the products. The relationships between 1,5-, 1,6- and possibly existing 1,7-homolytic hydrogen transfer in 1-octyl-radical, as well as successive 1,2-hydride shift in corresponding cation have been computed via Monte-Carlo method. Taking into account that ratios of 1,5-/1,6-homolytic rearrangements in 1-octyl- and 1-tridecyl radical are approximately the same, the simulation shows very low involvement of 1,7-hydrogen rearrangement (1,5-/1,6-/1,7-hydrogen rearrangement = 85:31:1) in 1-octyl radical.
- Teodorovi?, Aleksandar V.,Badjuk, Dalibor M.,Stevanovi?, Nenad,Pavlovi?, Radoslav Z.
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- Copper-catalyzed alkene arylation with diaryliodonium salts
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Alkenes and arenes represent two classes of feedstock compounds whose union has fundamental importance to synthetic organic chemistry. We report a new approach to alkene arylation using diaryliodonium salts and Cu catalysis. Using a range of simple alkenes, we have shown that the product outcomes differ significantly from those commonly obtained by the Heck reaction. We have used these insights to develop a number of new tandem and cascade reactions that transform readily available alkenes into complex arylated products that may have broad applications in chemical synthesis.
- Phipps, Robert J.,McMurray, Lindsay,Ritter, Stefanie,Duong, Hung A.,Gaunt, Matthew J.
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supporting information; experimental part
p. 10773 - 10776
(2012/08/07)
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- Cross-coupling of non-activated chloroalkanes with aryl grignard reagents in the presence of iron/N-heterocyclic carbene catalysts
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An efficient and high-yielding cross-coupling reaction of various primary, secondary, and tertiary alkyl chlorides with aryl Grignard reagents was achieved by using catalytic amounts of N-heterocyclic carbene ligands and iron salts. This reaction is a simple and efficient arylation method having applicability to a wide range of industrially abundant chloroalkanes, including polychloroalkanes, which are challenging substrates under conventional cross-coupling conditions.
- Ghorai, Sujit K.,Jin, Masayoshi,Hatakeyama, Takuji,Nakamura, Masaharu
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supporting information; experimental part
p. 1066 - 1069
(2012/04/10)
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- Deoxygenation of aromatic ketones using transfer hydrogenolysis with Raney nickel in 2-propanol
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Aryl ketones are readily deoxygenated to their corresponding aryl alkanes upon treatment with Raney nickel catalyst in boiling 2-propanol. Taylor & Francis Group, LLC.
- Zuidema, Daniel R.,Williams, Sarah L.,Wert, Katherine J.,Bosma, Karin J.,Smith, Abigail L.,Mebane, Robert C.
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experimental part
p. 2927 - 2931
(2011/09/12)
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- Reactivity of mixed organozinc and mixed organocopper reagents: 6. Nickel-catalyzed coupling of methylarylzincs with primary alkyl halides; An atom-economic aryl-alkyl coupling
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A nickel-catalyzed process for the cross-coupling of mixed arylzincs and primary alkyl halides has been developed. The reaction of a methylarylzinc with a primary alkyl halide in THF in the presence of NiCl2/PPh 3 takes place with selective aryl transfer at room temperature in moderate yields. This protocol provides an atom-economic alternative to aryl-primary alkyl coupling using diarylzincs.
- Pekel, ?zgen ?mür,Erdik, Ender
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experimental part
p. 7087 - 7090
(2012/01/06)
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- Iron(II) complexes with functionalized amine-pyrazolyl tripodal ligands in the cross-coupling of aryl Grignard with alkyl halides
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Structurally distinctive Fe(ii) complexes with furan, thiophene and pyridine functionalized amine-pyrazolyl tripodal hybrid ligands have been synthesized and crystallographically characterized. The tether substituent at the central amine plays an active role in determining the coordination mode of the ligand and the metal geometry. All complexes are catalytically active towards cross-coupling of aryl Grignard reagents with primary and secondary alkyl halides with β-hydrogen under ambient conditions. ESI-MS spectra analysis revealed the ligand-stabilised Fe(ii) and Mg(ii) species. The Royal Society of Chemistry 2011.
- Xue, Fei,Zhao, Jin,Hor, T. S. Andy
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experimental part
p. 8935 - 8940
(2011/10/19)
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- CATALYST FOR CROSS-COUPLING REACTION, AND PROCESS FOR PRODUCTION OF AROMATIC COMPOUND USING THE SAME
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The present invention provides a process for efficiently producing an alkylated aromatic compound in good yield, by a cross-coupling reaction between an alkyl halide and an aromatic magnesium reagent. A process for producing an aromatic compound represented by Formula (1): [in-line-formulae]R—Ar′??(1)[/in-line-formulae]wherein R is a hydrocarbon group, and Ar′ is an aryl group;the process comprising:reacting a compound represented by Formula (2): [in-line-formulae]R—X??(2)[/in-line-formulae]wherein X is a halogen atom, and R is as defined above, with a magnesium reagent represented by Formula (3): [in-line-formulae]Ar′—MgY??(3)[/in-line-formulae]wherein Y is a halogen atom, and Ar′ is as defined above, in the presence of a catalyst for cross-coupling reactions comprising an iron compound and a bisphosphine compound represented by Formula (4): wherein Q is a divalent group derived from an aromatic ring by removing two hydrogen (H) atoms on adjacent carbon atoms; and each Ar is independently an aryl group.
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Page/Page column 17
(2011/07/06)
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- A structure-activity study of Ni-catalyzed alkyl-alkyl kumada coupling. Improved catalysts for coupling of secondary alkyl halides
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A structureactivity study was carried out for Ni catalyzed alkylalkyl Kumada-type cross coupling reactions. A series of new nickel(II) complexes including those with tridentate pincer bis(amino)amide ligands (RN2N) and those with bidentate mixed amino-amide ligands (RNN) were synthesized and structurally characterized. The coordination geometries of these complexes range from square planar, tetrahedral, to square pyramidal. The complexes had been examined as precatalysts for cross coupling of nonactivated alkyl halides, particularly secondary alkyl iodides, with alkyl Grignard reagents. Comparison was made to the results obtained with the previously reported Ni pincer complex [( MeN2N)NiCl]. A transmetalation site in the precatalysts is necessary for the catalysis. The coordination geometries and spin-states of the precatalysts have a small or no influence. The work led to the discovery of several well-defined Ni catalysts that are significantly more active and efficient than the pincer complex [(MeN2N)NiCl] for the coupling of secondary alkyl halides. The best two catalysts are [(HNN)Ni(PPh3)Cl] and [(HNN)Ni(2,4-lutidine)Cl]. The improved activity and efficiency was attributed to the fact that phosphine and lutidine ligands in these complexes can dissociate from the Ni center during catalysis. The activation of alkyl halides was shown to proceed via a radical mechanism.
- Ren, Peng,Vechorkin, Oleg,Von Allmen, Kim,Scopelliti, Rosario,Hu, Xile
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supporting information; experimental part
p. 7084 - 7095
(2011/06/26)
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- The first iron-catalysed aluminium-variant Negishi coupling: Critical effect of co-existing salts on the dynamic equilibrium of arylaluminium species and their reactivity
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The first example of an iron-catalysed Negishi coupling between arylaluminium reagents and alkyl halides illustrates that the co-existing salts highly influence the dynamic equilibrium of the organoaluminium species, and have a critical effect on the reactivity and selectivity of the coupling reaction.
- Kawamura, Shintaro,Ishizuka, Kentaro,Takaya, Hikaru,Nakamura, Masaharu
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supporting information; experimental part
p. 6054 - 6056
(2010/11/02)
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- Liquid-crystalline polymorphism of symmetrical azobananas: Bis(4-(4-alkylphenyl)azophenyl) 2-nitroisophtalates
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In this paper we present a series of novel compounds, bis(4-(4-alkylphenyl) azophenyl) 2-nitroisophtalates, which exhibit nematic and banana-type liquidcrystalline phases. The alkyl chain length varies from 1 to 18 carbons. The first ten members of this series exhibit nematic phase. The last eleven compounds exhibit banana-type liquid crystalline phases. The propyl and pentyl derivatives have extra second type of banana mesophase. Copyright Taylor & Francis Group, LLC.
- Zygadlo,Dardas,Nowicka,Hofmann,Galewski
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scheme or table
p. 283 - 291
(2011/08/02)
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- Vanadium-catalyzed cross-coupling reactions of alkyl halides with aryl grignard reagents
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Vanadium(III) chloride catalyzed cross-coupling reactions of alkyl halides with arylmagnesium bromides. Various arylmagnesium bromides, except for an ortho-substituted arylmagnesium reagent, could be used for the reaction. Among alkyl halides tested, cyclohexyl halides and primary alkyl halides were good substrates. The reactions likely proceed via carbon-centered radical intermediates. 2008 The Chemical Society of Japan.
- Yasuda, Shigeo,Yorimitsu, Hideki,Oshima, Koichiro
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experimental part
p. 287 - 290
(2009/03/12)
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- Iron-catalyzed desulfinylative C-C cross-coupling reactions of sulfonyl chlorides with grignard reagents
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(Chemical Equation Presented) A friendly couple: Conditions have been uncovered that allow the desulfinylative C-C cross-coupling reaction of inexpensive sulfonyl chlorides and Grignard reagents (see scheme, acac = acetylacetonate, NMP = N-methylpyrrolidone). The reactions rely on environmentally friendly iron catalysts and do not require expensive and/or toxic ligands.
- Rao Volla, Chandra M.,Vogel, Pierre
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p. 1305 - 1307
(2008/12/22)
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- High yielding alkylations of unactivated sp3 and sp2 centres with alkyl-9-BBN reagents using an NHC-based catalyst: Pd-PEPPSI-IPr
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High yielding, room temperature cross couplings of unactivated alkyl bromides and aryl bromides/chlorides with alkyl-9-BBN reagents has been achieved using an NHC-based catalyst (Pd-PEPPSI-IPr) via a general, functional-group tolerant and easily implemented protocol. The Royal Society of Chemistry.
- Valente, Cory,Baglione, Sylvia,Candito, David,O'Brien, Christopher J.,Organ, Michael G.
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p. 735 - 737
(2008/09/17)
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- Iron-catalyzed alkylations of aromatic Grignard reagents
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(Chemical Equation Presented) Any old iron: Two efficient iron-catalyzed cross-coupling reactions between aryl Grignard reagents and alkyl bromides were developed that are suitable for large-scale applications. The first procedure uses iron acetylacetonate and involves a cooperative effect between the two ligands N,N,N′,N′-tetramethylethylenediamine (TMEDA) and hexamethylenetetraamine (HMTA), while the second procedure uses [(FeCl 3)2(tmeda)3] as catalyst. 2007 Wiley-VCH Verlag GmbH & Co. KGaA.
- Cahiez, Gerard,Habiak, Vanessa,Duplais, Christophe,Moyeux, Alban
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p. 4364 - 4366
(2008/03/12)
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- Stille cross-coupling of activated alkyltin reagents under "ligandless" conditions
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(Chemical Equation Presented) Monoalkyltins activated by a fluoride source are shown to be as reactive as their vinyl or aryl homologues in the Stille coupling reaction, thus providing an easy entry into the pallado-catalyzed formation of Csp3-Csp2 bonds. In addition to this uncommon reactivity, this methodology holds several advantages such as (i) a quantitative preparation of stable and easy to handle alkyltin reagents 2, (ii) a simplified coupling procedure without any phosphine added ligand under neutral conditions, and (iii) a facile purification step of the organic products from the inorganic nontoxic tin byproducts.
- Herve, Agnes,Rodriguez, Alain L.,Fouquet, Eric
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p. 1953 - 1956
(2007/10/03)
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- Method for formulation of synthetic gas oils or additives for gas oil
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The invention relates to a method for formulation of a synthetic gas oil or an additive for gas oil in which an alkyl-aromatic compound or a mixture of alkyl-aromatic compounds is selected based on at least one parameter that is selected from the group that consists of the number of cycles of the aromatic core, the number of alkyl chains that are grafted to the aromatic cycle, the length of the alkyl chain or chains, the position of the aromatic cycle or cycles on the alkyl chain or chains of said alkyl-aromatic compound or compounds such that the cetane number of the synthetic gas oil or the additive for gas oil is greater than 30. The invention also relates to a process for the production of alkyl-aromatic compounds for use as a gas oil or additive.
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Page/Page column 2
(2008/06/13)
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- Ligands for Palladium-Catalyzed Cross-Couplings of Alkyl Halides: Use of an Alkyldiaminophosphane Expands the Scope of the Stille Reaction
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Alkyldiaminophosphanes (PR(NR′2)2) are a new class of ligands for palladium-catalyzed cross-couplings of alkyl halides (see scheme). In comparison with trialkylphosphanes, alkyldiaminophosphanes furnish more versatile catalysts for Stille reactions of alkyl bromides and achieve efficient couplings with both vinyl and aryl stannanes, Furthermore, Pd/PR(NR′2)2 provides the first method for accomplishing Stille cross-couplings of simple alkyl iodides that bear β-hydrogen atoms.
- Tang, Haifeng,Menzel, Karsten,Fu, Gregory C.
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p. 5079 - 5082
(2007/10/03)
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- Palladium-catalyzed negishi cross-coupling reactions of unactivated alkyl iodides, bromides, chlorides, and tosylates
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A single method (2% Pd2(dba)3/8% PCyp 3/NMI in THF/NMP at 80°C; Cyp = cyclopentyl) achieves the cross-coupling of a range of β-hydrogen-containing primary alkyl iodides, bromides, chlorides, and tosylates with an array of alkyl-, alkenyl-, and arylzinc halides. The process is compatible with a variety of functional groups, including esters, amides, imides, nitriles, and heterocycles.
- Zhou, Jianrong,Fu, Gregory C.
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p. 12527 - 12530
(2007/10/03)
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- Discotic liquid crystals of transition metal complexes, 31: Establishment of mesomorphism and thermochromism of bis[1,2-bis(4-n-alkoxyphenyl)ethane-1,2-dithiolene]nickel complexes
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Two series of bis[1,2-bis(4-n-alkylphenyl)ethane-1,2-dithiolene]nickel, Cn-Ni (n= 1-12), and bis[1,2-bis(4-n-alkoxyphenyl)ethane-1,2-dithiolene]nickel, CnO-Ni(n = 1-12, 14, 16, 18), have been synthesized. Their mesomorphism, thermochromism, supramolecular structures and π-acceptor property have been investigated by using different scanning calorimetry, polarizing microscopy, temperature-dependent X-ray diffraction technique, electronic spectroscopy and cyclic voltammetry. From the X-ray diffraction and electronic spectral results, it was established that the CnO-Ni complexes for n ≤ 10 exhibit two differently colored discotic lamellar (DL) mesophases whereas none of the Cn-Ni complexes has a mesophase, and that the thermochromism (brown→green) is attributable to a slow transformation from the Ni-Ni bonded dimers to the Ni-S bonded dimers.
- Horie,Takagi,Hasebe,Ozawa,Ohta
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p. 1063 - 1071
(2007/10/03)
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- On the Mechanism of the Reduction of Primary Halides with Grignard Reagents in the Presence of (dppf)PdCl2 or (dppf)Pd(0)
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Reaction of primary alkyl halides with Grignard reagents in the presence (dppf)PdCl2 or (dppf)Pd(0) leads to reduction of the halide.The mechanism of the reduction is dependent on the solvent and the Grignard reagent.In tetrahydrofuran, reduction is independent of palladium.The alkyl halide is largely reduced by β-hydride transfer from the Grignard reagent.Competing with hydride transfer is a halogen-metal exchange reaction, which converts the alkyl halide into the corresponding Grignard reagent.Protonation of reaction mixture then gives the observed products.Grignard reagents that do not possess β-hydrogens undergo the halogen-metal exchange exclusively, but still lead to reduction of the alkyl halide.At subambient temperatures and in diethyl ether, reduction of primary alkyl halides with Grignard reagents in the absence of palladium catalysts is very slow.That reduction which does occur is almost exclusively the product of β-hydride transfer.The addition of (dppf)PdCl2 markedly accelerates the rate of reduction of alkyl halides in diethyl ether.The catalytic effect is proposed to occur through a catalytic cycle involving oxidative addition of the alkyl halide, hydride-transfer, and reductive-elimination steps.The order of the first two steps remains unclear.
- Yuan, Kaixu,Scott, William J.
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p. 6188 - 6194
(2007/10/02)
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- A RE-EXAMINATION OF THE PALLADIUM-CATALYZED CROSS COUPLING OF ALKYL IODIDES WITH ALKYL GRIGNARD REAGENTS
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Reaction of primary alkyl halides with Girgnard reagents in the presence of (dppf)Pd(O) or (dppf)PdCl2 leads to the reduction of the halide.
- Yuan, Kaixu,Scott, William J.
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p. 4779 - 4782
(2007/10/02)
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- A CONVENIENT REDUCTION OF ALKYLATED TOSYLMETHYL ISOCYANIDES: APPLICATIONS FOR THE SYNTHESIS OF NATURAL PRODUCTS
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A convenient and simple method for the reduction of mono- and dialkylated tosylmethyl isocyanides with lithium in liquid ammonia to corresponding hydrocarbons is described.The utility of this methodology adopted in the synthesis of tricos-9Z-ene (7g), a sex pheromone of common house fly, (-)-1S,5R,7S-exo-brevicomin (17), an antipode of sex pheromone of Western pine beetle and (4S,5S)-5-hydroxy-4-decanolide (L-factor, 19), a proposed autoregulator for leukaemomycin biosynthesis.
- Yadav, J. S.,Reddy, P. Satyanarayana,Joshi, Bhalchandra V.
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p. 7243 - 7254
(2007/10/02)
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