- Tailoring the Molecular Properties with Isomerism Effect of AIEgens
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It is challenging to achieve precise control on the properties of organic π-functional materials to widen their practical applications. On the other hand, the study of aggregation-induced emission luminogens (AIEgens) helps achieve such goals because of i
- Chen, Ming,Liu, Junkai,Liu, Feng,Nie, Han,Zeng, Jiajie,Lin, Gengwei,Qin, Anjun,Tu, Mei,He, Zikai,Sung, Herman H. Y.,Williams, Ian D.,Lam, Jacky W. Y.,Tang, Ben Zhong
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- H2O2-mediated room temperature synthesis of 2-arylacetophenones from arylhydrazines and vinyl azides in water
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An environmentally benign, cost-efficient and practical methodology for the room temperature synthesis of 2-arylacetophenones in water has been discovered. The facile and efficient transformation involves the oxidative radical addition of arylhydrazines with α-aryl vinyl azides in the presence of H2O2 (as a radical initiator) and PEG-800 (as a phase-transfer catalyst). From the viewpoint of green chemistry and organic synthesis, the present protocol is of great significance because of using cheap, non-toxic and readily available starting materials and reagents as well as amenability to gram-scale synthesis, which provides an attractive strategy to access 2-arylacetophenones.
- Luo, Mengqiang,Zhang, Yaohong,Fang, Ping,Li, Yan,Qi, Chenze,Li, Yong,Shen, Runpu,Cheng, Kai,Wang, Hai
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supporting information
p. 630 - 635
(2022/02/01)
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- Intramolecular Anti-Carbolithiation of Alkynes: Stereo-Directing Effect of Lithium-Coordinating Substituents
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This paper presents the results of our investigations on the stereochemical course of intramolecular carbolithiation of alkynes. It is shown that the presence of a lithium-chelating propargylic substituent completely reverses the otherwise favored syn-pro
- Ly, Kim Uyen,Boussonnière, Anne,Castanet, Anne-Sophie
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supporting information
(2022/01/19)
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- Benzylic Aroylation of Toluenes Mediated by a LiN(SiMe3)2/Cs+System
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Chemoselective deprotonative functionalization of benzylic C-H bonds is challenging, because the arene ring contains multiple aromatic C(sp2)-H bonds, which can be competitively deprotonated and lead to selectivity issues. Recently it was found that bimetallic [MN(SiMe3)2 M = Li, Na]/Cs+ combinations exhibit excellent benzylic selectivity. Herein, is reported the first deprotonative addition of toluenes to Weinreb amides mediated by LiN(SiMe3)2/CsF for the synthesis of a diverse array of 2-arylacetophenones. Surprisingly, simple methyl benzoates also react with toluenes under similar conditions to form 2-arylacetophenones without double addition to give tertiary alcohol products. This finding greatly increases the practicality and impact of this chemistry. Some challenging substrates with respect to benzylic deprotonations, such as fluoro and methoxy substituted toluenes, are selectively transformed to 2-aryl acetophenones. The value of benzylic deprotonation of 3-fluorotoluene is demonstrated by the synthesis of a key intermediate in the preparation of Polmacoxib.
- Gu, Yuanyun,Zhang, Zhen,Wang, Yan-En,Dai, Ziteng,Yuan, Yaqi,Xiong, Dan,Li, Jie,Walsh, Patrick J.,Mao, Jianyou
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supporting information
p. 406 - 418
(2022/01/14)
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- Palladium-catalyzed synthesis of α-aryl acetophenones from styryl ethers and aryl diazonium saltsviaregioselective Heck arylation at room temperature
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Preparation of α-aryl acetophenones from styryl ethers and aryldiazonium salts is described. The reaction is catalyzed by palladium acetate at room temperature in the absence of ligand and base. The developed method is highly attractive in terms of reaction conditions, substrate scope, functional group tolerance and yields. Synthetic applications of the present method are demonstrated by preparing α-aryl indoles and 3-aryl isocoumarin from styryl ethers.
- Kandasamy, Jeyakumar,Lee, Yong Rok,Singh, Adesh Kumar,Venkatesh, Rapelly
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supporting information
p. 7832 - 7837
(2021/09/28)
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- Ruthenium(II)-Catalyzed Cross-Coupling of Benzoyl Formic Acids with Toluenes: Synthesis of 2-Phenylacetophenones
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Herein, we report a direct method to synthesize 2-phenylacetophenone through a ruthenium(II)-catalyzed cross-coupling reaction between acyl and benzyl radical. The various derivatives of 2-phenylacetophenone were prepared easily in moderate to good yields. These reactions provide a straightforward pathway to synthesize a variety of ketones bearing various functional groups.
- Chen, Yujie,Dai, Chenyang,Huang, Zhibin,Jiang, Yaqiqi,Shu, Sai,Yang, Shan,Zhao, Yingsheng
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p. 2955 - 2961
(2021/07/22)
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- Sequential Suzuki-Miyaura Coupling/Lewis Acid-Catalyzed Cyclization: An Entry to Functionalized Cycloalkane-Fused Naphthalenes
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Functionalized angular cycloalkane-fused naphthalenes were prepared using a two-step process involving a Pd-catalyzed Suzuki-Miyaura coupling of aryl pinacol boronates and vinyl triflates followed by a boron trifluoride etherate-catalyzed cycloaromatization.
- Mahecha-Mahecha, Camilo,Lecornué, Frédéric,Akinari, Sumita,Charote, Thomas,Gamba-Sánchez, Diego,Ohwada, Tomohiko,Thibaudeau, Sébastien
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supporting information
p. 6267 - 6271
(2020/09/02)
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- Parecoxib sodium substituted impurity and preparation method thereof
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The invention relates to a parecoxib sodium substituted impurity and a preparation method thereof. The preparation method comprises the following steps: carrying out a reaction on a compound with a structure represented by a formula I with hydroxylamine h
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Paragraph 0137-0144
(2020/06/05)
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- Construction of 1,3-Dithio-Substituted Tetralins by [1,5]-Alkylthio Group Transfer Mediated Skeletal Rearrangement
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A novel skeletal rearrangement involving a [1,5]-alkylthio group transfer/cyclization sequence is described. Treatment of benzylidene malonates having a thioketal moiety at the homobenzyl position with a catalytic amount of Sc(OTf)3 afforded alkylthio group rearranged adducts in good chemical yields. Detailed investigation of the reaction mechanism revealed that an intramolecular conjugate addition/ring opening sequence (not through-space transfer) is the key to achieving this reaction.
- Hisano, Naoya,Kamei, Yuto,Kansaku, Yaoki,Yamanaka, Masahiro,Mori, Keiji
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supporting information
p. 4223 - 4226
(2018/07/29)
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- Strategy for Overcoming Full Reversibility of Intermolecular Radical Addition to Aldehydes: Tandem C-H and C-O Bonds Cleaving Cyclization of (Phenoxymethyl)arenes with Carbonyls to Benzofurans
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An intermolecular addition of carbon radicals enabled by a cascade radical coupling strategy is developed. It includes an intermolecular alkyl radical addition to a carbonyl group followed by an intramolecular alkoxy radical addition to haloarenes and produces substituted benzofurans in high yields. The radical nature of this reaction is explored by radical trapping experiments and EPR analysis. The mechanism is investigated by KIE experiments and control experiments. This method could provide rapid and practical access to the key intermediate of TAM-16, a safe and potent antibacterial agent for treating tuberculosis, and, therefore, is of great importance for organic synthesis and the pharmaceutical industry.
- Zheng, Hong-Xing,Shan, Xiang-Huan,Qu, Jian-Ping,Kang, Yan-Biao
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p. 3310 - 3313
(2018/06/11)
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- Two-Step One-Pot Synthesis of Unsymmetrical (Hetero)Aryl 1,2-Diketones by Addition-Oxygenation of Potassium Aryltrifluoroborates to (Hetero)Arylacetonitriles
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An efficient one-pot two-step procedure for the synthesis of unsymmetrical (hetero)aryl 1,2-diketones has been developed. The reaction proceeds through a palladium-catalyzed nucleophilic addition of potassium aryltrifluoroborates to aliphatic nitriles followed by a copper-catalyzed aerobic benzylic C–H oxygenation using molecular oxygen as a green oxidant. This represents the first example of the direct synthesis of unsymmetrical diaryl 1,2-diketones from arylacetonitriles. This method utilizes inexpensive, stable, nontoxic, and readily available starting materials, is highly effective in the presence of both electron-rich and electron-poor nitriles and aryltrifluoroborates, and tolerates a wide variety of functional groups. The synthetic utility of this transformation was shown by increasing the scale of the reaction and by carrying out the one-pot protocol for the preparation of quinoxaline and benzimidazole derivatives. A plausible reaction mechanism has also been proposed.
- Kumar, Yogesh,Jaiswal, Yogesh,Kumar, Amit
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p. 494 - 505
(2018/02/09)
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- Visible Light Mediated Reductive Cleavage of C-O Bonds Accessing α-Substituted Aryl Ketones
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C-O σ-bonds in multifaceted benzoin derivatives can be effectively cleaved as acetates using catalytic amounts of [Ru(bpy)3]Cl2 as photoredox catalyst in combination with Hantzsch ester and triethylamine as a sacrificial electron donor. This mild and operationally simple method is applicable to a great variety of substrates. Homo- and cross-benzoins, which are easily accessed by NHC (N-heterocyclic carbene) catalysis, with both electron-withdrawing and electron-donating substituents, including aryl halogenides, can be employed. The deoxygenated counterparts are isolated in good to excellent yields. These broadly accessible, α-substituted (nonsymmetric) aryl ketones are versatilely applicable for further transformations as illustrated by the syntheses of 2-arylbenzofurans.
- Speckmeier, Elisabeth,Padié, Clément,Zeitler, Kirsten
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p. 4818 - 4821
(2015/10/12)
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- A Remarkably Simple Hybrid Surfactant-NHC Ligand, Its Gold-Complex, and Application in Micellar Catalysis
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A combination of an N-heterocyclic carbene (NHC) ligand and a structurally simple surfactant has been realized, the hybrid surfactant-NHC. The related gold complex was synthesized, fully characterized, and applied in catalysis. This remarkably simple strategy allows, in combination with a co-surfactant, the application of gold catalysis in water. Just merge it! The hybrid of a surfactant and an N-heterocyclic carbene (NHC) ligand is reported and applied for the synthesis of the derived gold complex (see scheme). The new resulting NHC-based metallosurfactant can interact with surfactants to form micelles and allows micellar catalysis for gold catalysis in water.
- Rühling, Andreas,Galla, Hans-Joachim,Glorius, Frank
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p. 12291 - 12294
(2015/08/25)
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- Copper-catalyzed base-accelerated direct oxidation of C-H bond to synthesize benzils, isatins, and quinoxalines with molecular oxygen as terminal oxidant
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We describe herein an efficient and general copper (II)-catalyzed base-accelerated oxidation of the C-H bond to synthesize benzils and isatins. With similar oxidation system an efficient one-pot procedure for the synthesis of quinoxaline derivatives was realized. The two protocols feature using molecular oxygen as terminal oxidant, low catalyst loading, wide substrate scope, and high functional-group tolerance.
- Yu, Jing-Wen,Mao, Shuai,Wang, Yong-Qiang
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p. 1575 - 1580
(2015/03/14)
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- An expedient route to heterocycles through α-arylation of ketones and arylamides by microwave induced thermal SRN1 reactions
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Microwave irradiation promotes a quick aromatic nucleophilic substitution by a thermally induced electron transfer process to form new C-C bonds by the coupling of aryl radicals and enolate nucleophiles. Diverse 2-aryl-1- phenylethanones can be prepared by the direct α-arylation of acetophenone with different haloarenes. The ketone enolate anion is generated by deprotonation with tBuOK in DMSO and the reaction is carried out in a closed microwave vessel at 70-100°C for 10 min. This simple procedure also allows the synthesis of deoxybenzoin and indole heterocycle derivatives by inter- or intra-molecular ring closure reactions, with moderate to excellent substitution yields. This journal is the Partner Organisations 2014.
- Soria-Castro, Silvia M.,Caminos, Daniel A.,Penenory, Alicia B.
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p. 17490 - 17497
(2014/05/06)
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- Indoles synthesized from amines via copper catalysis
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N-Substituted indoles are synthesized from primary amines through a tandem reaction sequence. Initial condensation of the amine with an α-(o-haloaryl)ketone or aldehyde is followed by intramolecular aryl amination catalyzed by CuI. A variety of anilines and alkyl amines, including those with significant steric demands, are converted to indoles in high yields and with varying indole substitution.
- Besandre, Ronald,Jaimes, Miguel,May, Jeremy A.
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supporting information
p. 1666 - 1669
(2013/06/26)
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- Synthesis of benzo[b]furans by palladium-NHC catalyzed ring closure of o-bromobenzyl ketones
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The palladium-catalyzed ring closure of aryl o-bromobenzyl ketones, easily accessible from aromatic aldehydes and 2- bromobenzyl bromide, provides a straightforward route to 2-aryl- benzofurans. A study of the ring closure revealed that a heterocyclic car
- Farago, Janos,Kotschy, Andras
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experimental part
p. 85 - 90
(2009/06/18)
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- TiCl4-catalyzed indirect anti-Markovnikov hydration of alkynes: Application to the synthesis of benzo[b]furans
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(Chemical Equation Presented) An efficient methodology for the indirect anti-Markovnikov hydration of unsymmetrically substituted terminal and internal alkynes is based on TiCl4-catalyzed hydroamination reactions. Its application to ortho-alkynylhaloarenes, followed by a copper-catalyzed O-arylation, provides flexible access to substituted benzo[b]furans.
- Ackermann, Lutz,Kaspar, Ludwig T.
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p. 6149 - 6153
(2008/02/09)
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- Palladium-catalysed intramolecular enolate O-arylation and thio-enolate S-arylation: synthesis of benzo[b]furans and benzo[b]thiophenes
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Enolates derived from α-(ortho-haloaryl)-substituted ketones undergo palladium-catalysed C-O bond formation to deliver benzofuran products in good yield. A catalyst generated from Pd2(dba)3 and the ligand DPEphos effects the key bond
- Willis, Michael C.,Taylor, Dawn,Gillmore, Adam T.
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p. 11513 - 11520
(2007/10/03)
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- Ring-fluorinated naphthalene and indene synthesis via 6- and 5-endo-trig cyclizations of gem-difluoroalkenes by carbon nucleophiles
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The intramolecular vinylic substitution of gem-difluoroalkenes is accomplished with sp3 and sp2 carbon nucleophiles (2-arylethyllithium and aryllithium) in a 6-endo-trig and a normally disfavored 5- endo-trig fashion, leading to the
- Ichikawa, Junji,Miyazaki, Hiroyuki,Sakoda, Kotaro,Wada, Yukinori
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p. 585 - 593
(2007/10/03)
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- Structure-based design of carboxybiphenylindole inhibitors of the ZipA-FtsZ interaction.
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Structural features of two weak inhibitors of the ZipA-FtsZ protein-protein interaction which were found to bind to overlapping but different areas of the key binding site were combined in one new series of carboxybiphenyl-indoles with improved inhibitory
- Sutherland, Alan G,Alvarez, Juan,Ding, Weidong,Foreman,Kenny, Cynthia Hess,Labthavikul, Pornpen,Mosyak, Lidia,Petersen, Peter J,Rush 3rd., Thomas S,Ruzin, Alexey,Tsao, Desiree H H,Wheless, Karen L
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p. 4138 - 4140
(2007/10/03)
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- Reactions of o-iodohalobenzenes with carbanions of aromatic ketones. Synthesis of 1-aryl-2-(o-halophenyl)ethanones
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o-Iodohalobenzenes (X = I, Br, Cl) react in DMSO with the enolate ions of acetophenone, propiophenone and 1-(2-naphthyl)ethanone to afford mainly monosubstitution with retention of one halogen. The monosubstituted dehalogenated compounds are formed in low overall yields in the reactions of o-diiodobenzene with the carbanions of 1-(2-naphthyl)ethanone and of acetophenone and in the reaction of o-bromoiodobenzene with the carbanion of propiophenone. The reactions can be performed in the dark, with usually increased yields of substitution under irradiation, as well as under FeBr2 initiation. Treatment of 2-(2-bromophenyl)-1-phenylethanone with Cu bronze affords the ring closure benzofuran product. The degree of dehalogenation is discussed in terms of the energetics of the intramolecular electron transfer (ET) from the ArCO-π system to the C-halogen σ bond in the monosubstituted radical anions proposed as intermediates. The lack of ring closure of the radicals formed by dehalogenation of these radical anions is analyzed in terms of geometric factors.
- Baumgartner, Maria T.,Jimenez, Liliana B.,Pierini, Adriana B.,Rossi, Roberto A.
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p. 1092 - 1097
(2007/10/03)
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- Metallic Nickel-Mediated Synthesis of Ketones by the Reaction of Benzylic, Allylic, Vinylic, and Pentafluorophenyl Halides with Acid Halides
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Metallic nickel was investigated as a convenient coupling reagent for the synthesis of ketones by the reaction of benzylic, allylic, vinylic, and pentafluorophenyl halides with acid halides at 85 deg C in glyme.A variety of benzylic ketones with functional groups including halogen, cyano, methoxycarbonyl, and hydroxycarbonyl groups were prepared in good yields by this method.The reaction was demonstrated to proceed via organonickel halide intermediates formed by the smooth oxidative addition of benzylic and acyl halides to metallic nickel, which were trapped with electron-deficient olefins. (?-Allyl)nickel halides, prepared in situ at 85 deg C from allylic halides and the nickel, also worked for the preparation of ketones.Vinylic and pentafluorophenyl halides but not alkyl halides reacted with acid halides to give the corresponding ketones in moderate yields.
- Inaba, Shin-ichi,Rieke, Reuben D.
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p. 1373 - 1381
(2007/10/02)
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