- 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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- 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; 0143-0146
(2018/09/13)
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- Chemoselective Transformation of Diarylethanones to Arylmethanoic Acids and Diarylmethanones and Mechanistic Insights
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The chemoselective transformation of diarylethanones via either aerobic oxidative cleavage to give arylmethanoic acids or tandem aerobic oxidation/benzilic acid rearrangement/decarboxylation to give diarylmethanones has been developed. The transformation is controllable and applicable to a broad spectrum of substrates and affords the desired products in good to excellent yields. Mechanistic insights with control reactions, 1H NMR tracking, and single-crystal X-ray diffraction reveal a complex mechanistic network in which two common intermediates, α-ketohydroperoxide and diarylethanedione, and three plausible pathways are proposed and verified. These pathways are interlinked and can be switched reasonably by changing the reaction conditions. This method enables scalable synthesis and access to a number of valuable compounds, including vitamin B3, diphenic acid, and the nonsteroidal anti-inflammatory drug ketoprofen. The present protocol represents a step forward in exploiting complex mechanistic networks to control reaction pathways, achieving divergent syntheses from the same class of starting materials.
- Wang, Xing,Chen, Rui-Xi,Wei, Zeng-Feng,Zhang, Chen-Yang,Tu, Hai-Yang,Zhang, Ai-Dong
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p. 238 - 249
(2016/01/15)
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- Palladium-catalyzed acylative cross-coupling of amides with diarylborinic acids and sodium tetraarylborates
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Abstract A general and efficient acylative Suzuki coupling of active amides with diarylborinic acids has been achieved by using 1 mol% Pd(PCy3)2Cl2/0.6 mol% PCy3 as catalyst system taking advantage of modifiable reactivities of acyl-nitrogen bonds of amides. Both electronic and steric influences from either aryl or acyl counterparts on the coupling proved to be negligible or small. A variety of aryl ketones including sterically hindered ones could be synthesized by the coupling of diarylborinic acids in good to excellent yields. Sodium tetraarylborates could also be used as high atom-economy aryl source in the palladium-catalyzed cross-coupling with active amides.
- Li, Xijing,Zou, Gang
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p. 136 - 145
(2015/07/27)
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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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- One-pot synthesis of diarylmethanones through palladium-catalyzed sequential coupling and aerobic oxidation of aryl bromides with acetophenone as a latent carbonyl donor
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A one-pot palladium-catalyzed synthesis of symmetrical and unsymmetrical diarylmethanones using acetophenone and aryl bromides as raw materials has been developed. In this reaction, acetophenone acts as a latent carbonyl donor and two pathways of palladium-catalyzed sequential coupling and aerobic oxidation are identified. The reaction is applicable to a spectrum of substrates and delivers the products in moderate to good yields. This method can be used for the synthesis of ketoprofen, a nonsteroidal anti-inflammatory drug, in a two-step procedure and 45% overall yield.
- Wang, Xing,Liu, Fu-Di,Tu, Hai-Yang,Zhang, Ai-Dong
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p. 6554 - 6562
(2014/08/05)
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- The synthesis and properties of vinyl substituted naphthopyrans and their styrene copolymers
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A comprehensive series of mono-, di- and tri-bromo-3H-naphtho[2,1-b]pyrans was synthesised by the traditional union of a 2-naphthol with an alkynol. The bromine atom(s) in these naphthopyrans was readily replaced by a vinyl group using a Suzuki coupling reaction with vinyl boronic anhydride pyridine complex. The efficiency of the Suzuki vinylation reaction decreases with the increasing number of bromine atoms to be substituted. The vinylnaphthopyrans served as styrene analogues and readily underwent a thermally initiated free radical addition co-polymerisation with styrene to efficiently afford low molecular weight poly(styrene-co-naphthopyrans). The photochromic response of the bromonaphthopyrans and vinylnaphthopyrans followed the established colour-structure relationships for photochromic naphthopyrans. The photochromic response of toluene solutions of the poly(styrene-co-naphthopyrans) was characterised by a hypsochromic shift of the λmax relative to that recorded for the vinylnaphthopyran monomers. Increased half-lives were noted for the copolymers derived from the bis- and tris-vinylnaphthopyrans where some degree of crosslinking was expected. A further hypsochromic shift in λmax resulted for the thin films of the poly(styrene-co- naphthopyrans). Of particular note was the behaviour of the 3-(2-vinylphenyl)-3- phenylnaphthopyran which gave the typical yellow colour of the photomerocyanine coupled with the predictable large half-life. However, all photochromism of this naphthopyran was lost upon polymerisation suggesting that an alternative pathway supervenes in the expected polymerisation sequence.
- Blackwell, Catherine J.,Gabbutt, Christopher D.,Guthrie, James T.,Heron, B. Mark
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p. 408 - 420
(2012/08/28)
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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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- 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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- An efficient and practical sequential one-pot synthesis of suprofen, ketoprofen and other 2-arylpropionic acids
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A novel sequential double carbonylation to synthesize anti-inflammatory drugs such as Ketoprofen and Suprofen has been developed. Starting from easily available aryl halides and arylboronic acids a one-pot carbonylative Suzuki and hydroxycarbonylation reaction sequence proceeds in good selectivity and high yield in the presence of the palladium/cataCXium A catalyst system. Applying optimized conditions different 2-arylpropionic acids were synthesized in good yields.
- Neumann, Helfried,Brennfuehrer, Anne,Beller, Matthias
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experimental part
p. 2437 - 2442
(2009/10/06)
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- Synthesis of ketones from acyl chlorides and triorganoindium reagents by Pd-catalyzed cross-coupling
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Triorganoindium reagents prepared from indium tribromide and 3 equiv of organolithium reagents react with acyl chlorides in palladium-catalyzed cross-coupling for preparation of new ketones. Copyright Taylor & Francis Group, LLC.
- Croix,Balland-Longeau,Duchene,Thibonnet, Jerome
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p. 3261 - 3270
(2007/10/03)
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- Potassium organotrifluoroborates: New partners in palladium-catalysed cross-coupling reactions
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The preparation of various potassium organotrifluoroborates bearing either aryl, alkenyl, or alkynyl substituents is described. These stable salts are shown to be very efficient partners in palladium-catalysed cross- coupling reactions with arenediazonium salts, affording biaryl and styrene derivatives in high yields.
- Darses, Sylvain,Michaud, Guillaume,Genet, Jean-Pierre
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p. 1875 - 1883
(2007/10/03)
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- Potassium vinyltrifluoroborate: A stable and efficient vinylating agent of arenediazonium salts using palladium catalysts
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The air stable potassium vinyltrifluoroborate I was efficiently prepared in one step from vinylmagnesium chloride and used in palladium cross-coupling reactions with arenediazonium salts affording functionalized styrenes.
- Darses, Sylvain,Michaud, Guillaume,Genet, Jean-Pierre
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p. 5045 - 5048
(2007/10/03)
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