- Nickel-Catalyzed Reductive Cross-Coupling of Aryl Bromides with Vinyl Acetate in Dimethyl Isosorbide as a Sustainable Solvent
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A nickel-catalyzed reductive cross-coupling has been achieved using (hetero)aryl bromides and vinyl acetate as the coupling partners. This mild, applicable method provides a reliable access to a variety of vinyl arenes, heteroarenes, and benzoheterocycles, which should expand the chemical space of precursors to fine chemicals and polymers. Importantly, a sustainable solvent, dimethyl isosorbide, is used, making this protocol more attractive from the point of view of green chemistry.
- Su, Mincong,Huang, Xia,Lei, Chuanhu,Jin, Jian
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supporting information
p. 354 - 358
(2022/01/15)
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- A donor-acceptor complex enables the synthesis of: E -olefins from alcohols, amines and carboxylic acids
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Olefins are prevalent substrates and functionalities. The synthesis of olefins from readily available starting materials such as alcohols, amines and carboxylic acids is of great significance to address the sustainability concerns in organic synthesis. Metallaphotoredox-catalyzed defunctionalizations were reported to achieve such transformations under mild conditions. However, all these valuable strategies require a transition metal catalyst, a ligand or an expensive photocatalyst, with the challenges of controlling the region- and stereoselectivities remaining. Herein, we present a fundamentally distinct strategy enabled by electron donor-acceptor (EDA) complexes, for the selective synthesis of olefins from these simple and easily available starting materials. The conversions took place via photoactivation of the EDA complexes of the activated substrates with alkali salts, followed by hydrogen atom elimination from in situ generated alkyl radicals. This method is operationally simple and straightforward and free of photocatalysts and transition-metals, and shows high regio- and stereoselectivities.
- Chen, Kun-Quan,Shen, Jie,Wang, Zhi-Xiang,Chen, Xiang-Yu
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p. 6684 - 6690
(2021/05/31)
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- Photocatalytic carbocarboxylation of styrenes with CO2for the synthesis of γ-aminobutyric esters
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Metal-free photoredox-catalyzed carbocarboxylation of various styrenes with carbon dioxide (CO2) and amines to obtain γ-aminobutyric ester derivatives has been developed (up to 91% yield, 36 examples). The radical anion of (2,3,4,6)-3-benzyl-2,4,5,6-tetra(9H-carbazol-9-yl)benzonitrile (4CzBnBN) possessing a high reduction potential (?1.72 Vvs.saturated calomel electrode (SCE)) easily reduces both electron-donating and electron-withdrawing group-substituted styrenes.
- Hahm, Hyungwoo,Han, Min Su,Hong, Sukwon,Kim, Jiyun,Ryoo, Jeong Yup
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p. 6301 - 6312
(2021/07/28)
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- Copper-Catalyzed Asymmetric Radical 1,2-Carboalkynylation of Alkenes with Alkyl Halides and Terminal Alkynes
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A copper-catalyzed intermolecular three-component asymmetric radical 1,2-carboalkynylation of alkenes has been developed, providing straightforward access to diverse chiral alkynes from readily available alkyl halides and terminal alkynes. The utilization of a cinchona alkaloid-derived multidentate N,N,P-ligand is crucial for the efficient radical generation from mildly oxidative precursors by copper and the effective inhibition of the undesired Glaser coupling side reaction. The substrate scope is broad, covering (hetero)aryl-, alkynyl-, and aminocarbonyl-substituted alkenes, (hetero)aryl and alkyl as well as silyl alkynes, and tertiary to primary alkyl radical precursors with excellent functional group compatibility. Facile transformations of the obtained chiral alkynes have also been demonstrated, highlighting the excellent complementarity of this protocol to direct 1,2-dicarbofunctionalization reactions with C(sp2/sp3)-based reagents.
- Dong, Xiao-Yang,Cheng, Jiang-Tao,Zhang, Yu-Feng,Li, Zhong-Liang,Zhan, Tian-Ya,Chen, Ji-Jun,Wang, Fu-Li,Yang, Ning-Yuan,Ye, Liu,Gu, Qiang-Shuai,Liu, Xin-Yuan
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supporting information
p. 9501 - 9509
(2020/05/18)
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- A process for the preparation and synthetic ChondriamideA and ChondriamideC method (by machine translation)
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The invention provides a process for the preparation of synthetic Chondriamide A and Chondriamide C and method, wherein the invention provides a process for the preparation, including: formula (I) compounds of structure, palladium catalyst, phosphorus ligand, alkali and organic solvent at room temperature the illumination reaction, formula (II) structure obtained olefin; wherein through the selection of a particular phosphorus ligand; make the method of the invention can be under the photocatalysis, room temperature to realize high-efficient catalytic conversion, and the mild reaction conditions, simple operation, in line with the development of green environment-friendly chemical requirements, and the range of choice of substrate and functional group compatibility has more universal, and has outstanding chemical selectivity; and the method can be successfully applied to complex molecular introducing carbon-carbon double bond to the programme, to optimize a part of the drug molecular synthesis strategy, improve the synthesis efficiency, reduce the cost, with industrial synthetic value and prospects. (by machine translation)
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Paragraph 0078-0082; 0157-0160
(2018/09/13)
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- Low-Pressure Cobalt-Catalyzed Enantioselective Hydrovinylation of Vinylarenes
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An efficient and practical protocol for the enantioselective cobalt-catalyzed hydrovinylation of vinylarenes with ethylene at low (1.2 bar) pressure has been developed. As precatalysts, stable [L2CoCl2] complexes are employed that are activated in situ with Et2AlCl. A modular chiral TADDOL-derived phosphine-phosphite ligand was identified that allows the conversion of a broad spectrum of substrates, including heterocyclic vinylarenes and vinylferrocene, to smoothly afford the branched products with up to 99 % ee and virtually complete regioselectivity. Even polar functional groups, such as OH, NH2, CN, and CO2R, are tolerated.
- Movahhed, Sohajl,Westphal, Julia,Dindaro?lu, Mehmet,Falk, Anna,Schmalz, Hans-Günther
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supporting information
p. 7381 - 7384
(2016/05/24)
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- Iron-catalyzed hydromagnesiation: Synthesis and characterization of benzylic grignard reagent intermediate and application in the synthesis of ibuprofen
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Iron-catalyzed hydromagnesiation of styrene derivatives using ethylmagnesium bromide has been investigated for the synthesis of benzylic Grignard reagents. The benzylic Grignard reagent formed in the reaction was observed directly and its conformation in solution characterized by multinuclear and variable-temperature NMR spectroscopy. The Grignard reagent could be stored for at least 2 weeks without significant loss in activity. Hydromagnesiation of styrene in tetrahydrofuran gave a mixture of monoalkyl- and dialkylmagnesium species, (1-phenylethyl)magnesium bromide (2; RMgBr) and bis(1-phenylethyl)magnesium (3; R2Mg), with the equilibrium between these species lying in favor of the dialkylmagnesium species. The thermodynamic parameters of alkyl exchange for the reaction MgBr2 + R2Mg (3) 2RMgBr (2) were quantified, with the enthalpy and entropy of formation of 2 from MgBr2 and 3 calculated as 32 ± 7 and 0.10 ± 0.03 kJ mol-1, respectively. This methodology was applied, on a 10 mmol scale, as the key step in the synthesis of ibuprofen, using sequential iron-catalyzed alkyl-aryl and aryl-vinyl cross-coupling reactions to give 4-isobutylstyrene, which following hydromagnesiation and reaction with CO2 gave ibuprofen. Each step proceeded in excellent yield, at temperatures between 0 °C and room temperature, at atmospheric pressure. Inexpensive, nontoxic, and air- and moisture-stable iron(III) acetylacetonate was used as the precatalyst in each step in combination with inexpensive amine ligands.
- Greenhalgh, Mark D.,Kolodziej, Adam,Sinclair, Fern,Thomas, Stephen P.
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supporting information
p. 5811 - 5819
(2015/02/19)
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- Simultaneous identification of Fenton degradation by-products of diclofenac, ibuprofen and ketoprofen in aquatic media by comprehensive two-dimensional gas chromatography coupled with mass spectrometry
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Diclofenac, ibuprofen and ketoprofen are anti-inflammatory drugs intensively used both in human and animal treatment. Due to their high stability these compounds are partially removed by wastewater treatment plants and from this reason the development of some alternative treatments such as advanced oxidative processes are necessary. The main problems in the optimization of an advanced oxidative process rise from the difficulties which appear in the identification of degradation by-products necessary for the establishment of degradation pathway. In this paper a developed method for the simultaneous identification of Fenton degradation by-products of the three above mentioned pharmaceuticals is presented. The obtained results show the comprehensive two-dimensional gas chromatography coupled with mass spectrometry as a proper method for the analysis of the complex mixture of compounds resulted from the Fenton degradation process. Moreover, some compounds never mentioned in the scientific literature were identified. (Chemical Equation Presented).
- Beldean-Galea, Mihail Simion,Coman, Virginia,Copaciu, Florina,Thiébaut, Didier,Vial, Jér?me
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p. 1021 - 1027
(2015/07/15)
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- Enantioselective nickel-catalyzed hydrocyanation of vinylarenes using chiral phosphine-phosphite ligands and TMS-CN as a source of HCN
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Anti-headache chemistry: In the presence of a tailored modular P,P ligand the nickel-catalyzed addition of HCN, generated in situ from TMS-CN, to styrene derivatives proceeds with an unprecedented level of stereocontrol (up to 97 % ee) to give 2-aryl-acetonitriles, for example, the depicted precursor of Ibuprofen. Copyright
- Falk, Anna,Goederz, Anna-Lena,Schmalz, Hans-Guenther
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supporting information
p. 1576 - 1580
(2013/03/13)
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- Iron-catalyzed, highly regioselective synthesis of α-aryl carboxylic acids from styrene derivatives and CO2
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The iron-catalyzed hydrocarboxylation of aryl alkenes has been developed using a highly active bench-stable iron(II) precatalyst to give α-aryl carboxylic acids in excellent yields and with near-perfect regioselectivity. Using just 1 mol % FeCl2, bis(imino)pyridine 6 (1 mol %), CO 2 (atmospheric pressure), and a hydride source (EtMgBr, 1.2 equiv), a range of sterically and electronically differentiated aryl alkenes were transformed to the corresponding α-aryl carboxylic acids (up to 96% isolated yield). The catalyst was found to be equally active with a loading of 0.1 mol %. Preliminary mechanistic investigations show that an iron-catalyzed hydrometalation is followed by transmetalation and reaction with the electrophile (CO2).
- Greenhalgh, Mark D.,Thomas, Stephen P.
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supporting information; experimental part
p. 11900 - 11903
(2012/09/07)
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- Low pressure vinylation of aryl and vinyl halides via Heck-Mizoroki reactions using ethylene
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Aryl bromides and iodides in the presence of catalytic amounts of a palladacycle derived from acetophenone oxime and 2 equiv of potassium acetate react with ethylene under ambient pressure (15-30 psi) to give the corresponding vinylarenes. The reactions work with both electron-deficient and electron-rich aryl compounds and tolerate wide variety of common functional groups. Vinyl bromides lead to 1,3-dienes in moderate yields.
- Smith, Craig R.,RajanBabu
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supporting information; experimental part
p. 1102 - 1110
(2010/03/25)
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- A mild catalytic oxidation system: Ruthenium porphyrin and 2,6-dichloropyridine n-oxide applied for alkene dihydroxylation
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A new method was developed to transform alkenes into three types of functional molecules, including epoxides, aldehydes and 1,2-diols by using dichlororuthenium(IV) meso-tetrakis(2,6-dichlorophenyl)porphyrin [Ru(IV)(TDCPP)Cl2] as catalyst and 2,6-dichloropyridine N-oxide (Cl2pyNO) as the oxidant, in which the 1,2-diols were afforded via "one-pot" reactions in moderate yields. Copyright
- Hu, Wen-Xiang,Li, Pei-Rong,Jiang, Gaoxi,Che, Chi-Ming,Chen, Jian
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supporting information; experimental part
p. 3190 - 3194
(2011/02/23)
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- NC palladacycles in the Heck arylation of ethylene: Synthesis, structure and their reactivity
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Monomeric cyclopalladated complexes with NC coordination using ligands 2-phenylpyridine, 2-phenylquinoline, 8-methylquinoline have been synthesized and the structures have been determined by single crystal X-ray structure analysis. The crystal structures of monomeric palladacycles prepared using benzophenone oxime, and 2-phenylpyridine have also been determined. The use of these complexes in the Heck arylation of ethylene with 2-bromo-6-methoxynaphthalne (BMN) to give 2-vinyl-6-methoxynapthalene which is an intermediate for the synthesis of anti-inflammatory drug Naproxen has been examined and also arylation of ethylene with 3-bromo-benzophenone and 4-bromo-isobutylbenzene was investigated. These palladacycles with NC coordination show excellent catalytic activity with a TOF > 4000 h-1.
- Atla, Shashi B.,Kelkar, Ashutosh A.,Puranik, Vedavati G.,Bensch, Wolfgang,Chaudhari, Raghunath V.
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experimental part
p. 683 - 690
(2009/05/30)
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- Synthesis of E-aryl ethenesulfonamides: A simple one-pot, two-step procedure from 1-hydroxy-1-arylalkanes
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The unusual reactivity of 1-phenyl-1-ethane-sulfonic acid in thionyl chloride was investigated. Mechanistic considerations led us to set up a new and efficient synthesis of E-arylethenesulfonamides starting from 1-hydroxy-1-arylalkanes. The easy availability of the starting materials and the straightforward, one-pot procedure make this process an attractive method for the preparation of these compounds currently largely employed in chemical and pharmaceutical fields.
- Aramini, Andrea,Cesta, Maria C.,Coniglio, Silvia,Bijani, Christian,Colagioia, Sandro,D'Elia, Valerio,Allegretti, Marcello
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p. 7911 - 7914
(2007/10/03)
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- Performances of homogeneous charge transfer catalysts in the electrocarboxylation of benzyl halides
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The electrocarboxylation of benzyl halides to the corresponding carboxylic acids performed by homogeneous charge transfer catalysts is reported here. The performances of selected ester derivatives of benzoic acid and of the three isomers of benzenedicarboxylic acid as catalysts are evaluated on the basis of the faradaic efficiency of the carboxylation and of the decomposition rate of the catalyst. The standard redox potentials of catalysts are related to the selectivity of the process. Rates of catalyst decomposition appear to be dependent on the molar ratio [halide]/[catalyst] and on the cathode material.
- Scialdone, Onofrio,Filardo, Giuseppe,Galia, Alessandro,Mantione, Davide,Silvestri, Giuseppe
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p. 800 - 806
(2007/10/03)
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- New Syntheses of Ibuprofen and Naproxen
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A new route for the synthesis of α-arylpropionic acids, in particular for the two most important non-steroidal antiinflammatory compounds Ibuprofen (5) as well as racemic and optically active Naproxen (12), has been developed.N-(1-Arylethyl)formamides 2, 9 are dehydrated to the corresponding isocyanides 3, 10, and these are rearranged by flash pyrolysis to α-arylpropionitriles 4, 11 which are converted into α-arylpropionic acids 5, 12 by hydrolysis under standard conditions.The intermediate 1-(6-methoxy-2-naphthyl)-ethylamine is resolved via its tartrate or mandelic salts. Key Words : Isocyanide - cyanide rearrangement / Ibuprofen / Naproxen / Optically active 1-arylethylamines
- Wolber, Erwin K. A.,Ruechardt, Christoph
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p. 1667 - 1672
(2007/10/02)
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- 1,2-Di(4-isobutylphenyl)hydrocarbon and its preparation and uses as intermediate
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Novel compounds of 1,2-di(isobutylphenyl)ethane and 1,2-di(isobutylphenyl)ethylene, method for producing the same and method for preparing 4-isobutylstyrene and α-(4-isobutylphenyl)propionic acid from any of these compounds. In the preparation of 4-isobut
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- Synthesis of 2-Arylpropionaldehydes through Hydroformylation
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The rhodium-phospholes and rhodium-phosphanorbornadienes-catalyzed hydroformylation of the readily available vinylarenes 1-3 gives rise to arylpropionaldehydes 4-6 in good yields.
- Neibecker, Denis,Reau, Regis,Lecolier, Serge
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p. 5208 - 5210
(2007/10/02)
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- Asymmetric Hydroformylation Catalyzed by Homogeneous and Polymer-Supported Platinum Complexes Containing Chiral Phosphine Ligands
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A complex of Pt(II) containing the chiral ligand (2S,4S)-N-(tert-butoxycarbonyl)-4-(diphenylphosphino)-2-pirrolidine in the presence of stannous chloride catalyzed the hydroformylation of a variety of prochiral olefins.Although the branched/normal (b/n) ratios were low (ca. 0.5), high ee's were achieved in the hydroformylation of styrene (70-80percent), p-isobutylstyrene (80percent), 2-vinylnaphthalene (77percent), 2-ethenyl-6-methoxynaphthalene (81percent), 4-(2-thienylcarbonyl)styrene (78percent), vinyl acetate(82percent), N-vinylphthalimide (73percent), methyl methacrylate (60percent), and norbornene (60percent).When the hydroformylation of styrene, 2-ethenyl-6-methoxynaphthalene, and vinyl acetate with PtCl2/SnCl2 was carried out in the presence of triethyl orthoformate, enantiomerically pure acetals were obtained.The hydroformylation in the presence of ethyl orthoformate also could be carried out by using a catalyst containing the PtCl2/SnCl2 complex bound to 60-μm beads composed of cross-linked polystyrene.
- Parrinello, Giovanni,Stille, J. K.
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p. 7122 - 7127
(2007/10/02)
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- Substituted aryl ethylenes
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New substituted aryl ethylenes are disclosed which are produced by dehydration of the corresponding α- or β-(substituted aryl)ethyl alcohols or by dehydrohalogenation of the corresponding α- or β-(substituted aryl)ethyl halides.
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