- Rhodium-Catalyzed Annulation of N-Acetoxyacetanilide with Substituted Alkynes: Conversion of Nitroarenes to Substituted Indoles
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A general and efficient rhodium-catalyzed redox-neutral annulation of N-acetoxyacetanilides, readily accessible from nitroarenes, with alkynes has been accomplished for the synthesis of substituted indole derivatives. A wide range of substituted 2,3-diarylindoles were achieved from various substituted N-acetoxyacetanilides and symmetrical/unsymmetrical alkynes in good to excellent yields. The developed method was successfully integrated with the synthesis of N-acetoxyacetanilides for the efficient one-pot synthesis of indoles from nitroarenes. The important features are the introduction of N-acetoxyacetamide as a new directing group, redox-neutral annulation, an additive-free approach, wide functional group tolerance, an intramolecular version, and a one-pot reaction of nitroarenes. The method was further extended to the synthesis of potent higher analogues of indole, viz., pyrrolo[3,2-f]indoles and dibenzo[a,c]carbazoles. In addition, a plausible mechanism was proposed based on the isolation and stoichiometric study of a potential aryl-Rh intermediate.
- Ghorai, Jayanta,Ramachandran, Kuppan,Anbarasan, Pazhamalai
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p. 14812 - 14825
(2021/10/25)
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- Benzoazepine-Fused Isoindolines via Intramolecular (3 + 2)-Cycloadditions of Azomethine Ylides with Dinitroarenes
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Aminobenzaldehydes bearing a pendant 3,5-dinitrophenyl group react thermally with N-substituted α-amino acids to form unprecedented benzoazepine-fused isoindolines. The reaction proceeds via a dearomatization/rearomatization sequence involving an intramolecular (3 + 2)-cycloaddition between the in situ formed azomethine ylide and the dinitroarene. Various glycine derivatives are tolerated as well as branched substrates based on cyclic, α-mono-, and α,α-disubstituted amino acids, giving single diastereomers in many cases. The method is scalable and gives products with a nitro group ready for further manipulation.
- Wales, Steven M.,Rivinoja, Daniel J.,Gardiner, Michael G.,Bird, Melissa J.,Meyer, Adam G.,Ryan, John H.,Hyland, Christopher J. T.
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supporting information
p. 4703 - 4708
(2019/06/27)
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- A water soluble light activated hydrogen sulfide donor induced by an excited state meta effect
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We have utilized an m-amino benzyl based photoremovable protecting group (PRPG) to develop a new water soluble H2S donor. It efficiently releases H2S on demand in a spatio-temporally controlled fashion by an excited state "meta effect" with good chemical and photochemical quantum yield in an aqueous environment. The efficient photorelease of H2S under physiological conditions was also demonstrated by in vitro studies.
- Bera, Manoranjan,Maji, Somnath,Paul, Amrita,Ray, Souvik,Maiti, Tapas Kumar,Singh, N. D. Pradeep
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p. 9059 - 9064
(2019/10/28)
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- NOVEL COMPOUND, ORGANIC CATION TRANSPORTER 3 DETECTION AGENT, AND ORGANIC CATION TRANSPORTER 3 ACTIVITY INHIBITOR
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[Problem] The present invention addresses the problem of providing a novel compound. The present invention also addresses the problem of providing an OCT3 detection agent or an OCT3 activity inhibitor, which comprises the novel compound. [Solution] A compound represented by formula (A), a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof. ????????R1-R2-R3-R4?????(A)
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- Rasta resin-triphenylphosphine oxides and their use as recyclable heterogeneous reagent precursors in halogenation reactions
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Heterogeneous polymer-supported triphenylphosphine oxides based on the rasta resin architecture have been synthesized, and applied as reagent precursors in a wide range of halogenation reactions. The rasta resin-triphenylphosphine oxides were reacted with either oxalyl chloride or oxalyl bromide to form the corresponding halophosphonium salts, and these in turn were reacted with alcohols, aldehydes, aziridines and epoxides to form halogenated products in high yields after simple purification. The polymersupported triphenylphosphine oxides formed as a byproduct during these reactions could be recovered and reused numerous times with no appreciable decrease in reactivity.
- Xia, Xuanshu,Toy, Patrick H.
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supporting information
p. 1397 - 1405
(2014/07/22)
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- DMSO-catalyzed chlorination of alcohols using N-phenylbenzimidoyl chloride
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N-phenylbenzimidoyl chloride has been demonstrated as an efficient chlorination reagent catalyzed by dimethyl sulfoxide (DMSO) in conversion of alcohols to corresponding chlorides. The reaction conditions were mild, and most of the substrates gave satisfactory yields. The configuration inversion of the chlorination was proved using optically active phenyl alcohols. The amount of DMSO can be as low as 0.001 eq without reducing the efficiency of the chlorination. A plausible mechanism for the reaction was proposed and proved by experiments. The reaction is stereoselective and potentially chemoselective among primary benzyl alcohols, secondary benzyl alcohols, and unactivated aliphatic alcohols.
- Wang, Qiang,Xu, Jian,Xu, Zhou-Qing,Yan, Ji-Dan
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p. 2071 - 2076
(2013/06/05)
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- Sonication-induced self-assembly of flexible tris(ureidobenzyl)amine: From dimeric aggregates to supramolecular gels
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Tris(ureidobenzyl)amine derivatives 1a,b form dimeric aggregates in apolar solution and in the solid state. Specifically, the meta-substituted tris(urea) 1a is able to transform into supramolecular gels in certain solvents via sonication.
- Deng, Chao,Fang, Ru,Guan, Yangfan,Jiang, Juli,Lin, Chen,Wang, Leyong
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p. 7973 - 7975
(2012/09/08)
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- β-aryl nitrile construction via palladium-catalyzed decarboxylative benzylation of α-cyano aliphatic carboxylate salts
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The palladium-catalyzed decarboxylative benzylation of α-cyano aliphatic carboxylate salts with benzyl electrophiles was discovered. This reaction exhibits good functional group compatibility and proceeds under relatively mild conditions. A diverse range of quaternary, tertiary and secondary β-aryl nitriles can be conveniently prepared by this method. Copyright
- Shang, Rui,Huang, Zheng,Xiao, Xiao,Lu, Xi,Fu, Yao,Liu, Lei
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supporting information
p. 2465 - 2472,8
(2020/08/31)
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- Treatment of alcohols with tosyl chloride does not always lead to the formation of tosylates
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Treatment of substituted benzyl alcohols with tosyl chloride resulted in the formation of the corresponding chlorides, not the usual tosylates. A series of experiments demonstrated that it was possible to predict whether chlorination or tosylation would occur for substituted benzyl alcohols and pyridine methanols. Treatment of electron withdrawing group-substituted benzyl alcohols with tosyl chloride gave the corresponding chlorides in moderate yields under mild conditions, which provided a simple way to directly prepare chlorides from alcohols.
- Ding, Rui,He, Yong,Wang, Xiao,Xu, Jingli,Chen, Yurong,Feng, Man,Qi, Chuanmin
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experimental part
p. 5665 - 5673
(2011/09/20)
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- A highly chemoselective and rapid chlorination of benzyl alcohols under neutral conditions
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A rapid and highly selective chlorination method has been developed using 2,4,6-trichloro-1,3,5-triazine (TCT) catalyzed by dimethyl sulfoxide. The reactions take 10 to 40 minutes, and the yields are almost quantitative. The neutral reaction conditions are compatible with substrates bearing acid-labile functional groups. Both competitive intramolecular and intermolecular reactions for benzyl alcohols in the presence of aliphatic alcohols indicate high selectivity. The procedure has been successfully used in the selective chlorination of gastrodin, a clinically used neuromedicine. This procedure represents a useful new tool in organic and medicinal chemistry. Georg Thieme Verlag Stuttgart.
- Sun, Lili,Peng, Guisheng,Niu, Hongmei,Wang, Qiang,Li, Chunbao
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experimental part
p. 3919 - 3924
(2009/05/26)
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- Oxidation of benzylic alcohols and ethers to carbonyl derivatives by nitric acid in dichloromethane
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Nitric acid in dichloromethane may be successfully employed for the oxidation of benzylic alcohols and ethers to the corresponding carbonyl compounds. The proposed method proved to be of general applicability, affording very good yields of aldehydes and ketones and showing interesting chemoselectivity in many instances, allowing competitive aromatic nitration to be avoided, as well as - in the case of aldehydes - any further oxidation to carboxylic acids. The reaction probably proceeds by a radical mechanism, the active species in the oxidation process being NO2. Competitive formation of nitro esters was observed in some cases, whereas poor results were obtained with allylic and non-benzylic substrates. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Strazzolini, Paolo,Runcio, Antonio
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p. 526 - 536
(2007/10/03)
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- Nickel-catalyzed benzylic oxidation with NaOCl
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Ni(bpy)2Cl2 has been found to be an efficient catalyst for the oxidation of various alkylbenzenes with hypochlorite. Substituted toluenes having electron withdrawing group at 4-position were oxidized to the corresponding substituted benzoic acids in excellent yields.
- Yamazaki, Shigekazu
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p. 2211 - 2216
(2007/10/03)
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- Gas-phase substituent effects in highly electron-deficient systems. II. stabilities of 1-aryl-2,2,2-trifluoroethyl cations based on chloride-transfer equilibria
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The relative stabilities of 1-aryl-2,2,2-trifluoroethyl cations were determined based on the chloride ion-transfer equilibria in the gas phase. An application of the Yukawa-Tsuno equation to this substituent effect on the equilibrium constants gave a remarkably larger r+ of 1.53 and a ρ of-10.6, supporting our previous conclusion that the highly electron-deficient benzylic carbocation systems are characterized by extremely high resonance demands. This r+ value, furthermore, conformed a linear relationship between the r+ value and the relative stability of the unsubstituted member of the respective benzylic carbocations, clearly demonstrating a continuous spectrum of varying resonance demands characteristic of the stabilities of carbocations. The π-delocalization of the positive charge into the aryl π-system increases with the destabilization of a carbocation by the α-substituent(s) linked to the central carbon. In addition, the r + value of 1.53 for 1-aryl-2,2,2-trifluoroethyl cations was found to be in complete agreement with that for the solvolysis of 1-aryl-2,2,2- trifluoroethyl tosylates in 80% aq acetone. This reveals that the r+ value observed for this solvolysis must be the intrinsic resonance demand of a highly electron-deficient cationic transition state in the SN 1 ionizing process. The identity of the r+ value was consistent with our previous observation for other benzylic carbocation systems, indicating that the degree of the π-delocalization of the positive charge is identical between the cationic transition state and an intermediate cation for all benzylic systems, which cover a wide range of reactivity and stability of the carbocation. This leads us to the conclusion that the geometry of the transition state in the ionizing process of the SN1 solvolysis, which is a highly endothermic reaction, closely resembles the high-energy product, an intermediate cation.
- Mishima, Masaaki,Inoue, Hiroki,Fujio, Mizue,Tsuno, Yuho
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p. 1163 - 1169
(2007/10/03)
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- New applications of tungsten hexachloride (WCl6) in organic synthesis. Halo-de-hydroxylation and dihalo-de-oxo-bisubstitution reactions
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Tungsten hexachloride (WCl6) has been used for the halo-de-hydroxylation and dihalo-de-oxo-bisubstitution reactions of benzylic alcohols, benzaldehydes, acyloins, and epoxides to their chlorides, gem-dichlorides, vic-trichlorides, and vic-dichlorides respectively.
- Firouzabadi, Habib,Shiriny, Farhad
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p. 14929 - 14936
(2007/10/03)
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- Oxidation of Aromatic Compounds. I. Oxidation of Methyl Derivatives of Nitrobenzene and Aniline in the System HSO3F-PbO2
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Low-temperature oxidation of methyl derivatives of nitrobenzene and aniline in the system HSO3F-PbO2 proceeds with intermediate formation of radical cations and results in replacement of hydrogen in one or two methyl groups or yields compounds of the diphenylmethane and biphenyl series.
- Rudenko, A. P.,Korovina, N. S.,Aver'yanov, S. F.
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p. 1077 - 1083
(2007/10/03)
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- Substitution Reactions toward 2-Nitrobenzyl Pseudohalides. The Crystal Structure of 2-Nitrobenzyl Tellurocyanate
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The reactions between 2-nitrobenzyl pseudohalides, 2-NO2-PhCH2XCN, and pseudohalide ions, NCX- (X = S, Se or Te) have been studied kinetically in acetonitrile at 25.0 deg C.The reactions proceed through nucleophilic attack at the methylene carbon atom, forming exclusively the exchange products.The average nucleophilicity order, NCTe- >> NCSe- > NCS-, and the average leaving group order, NCTe- >/= NCSe- >/= NCS-, lead to a carbon basicity order NCTe- > NCSe- >/= NCS-, which is confirmed with equilibrium studies.A crystal structure determination of 2-nitrobenzyl tellurocyanate at ca. 135 deg C has revealed that the TeCN group is syn-clinal (gauche) to the C(CH2)-C(Ar) bond with a torsion angle of -48.5(5) deg.The TeCC plane forms an angle of 103.4(5) deg with the phenyl ring plane.In this conformation the steric influence of the 2-NO2 group in substitution reactions at the methylene carbon atom will be negligible except for bulky nucleophiles.The tellurium atom forms two fairly strong intermolecular bonds to nitrogen atoms from neighbouring tellurocyanate groups, viz. 2.889(6) Angstroem trans to the cyano group and 3.382(6) Angstroem trans to the methylene group.In the crystalline state the compound may be considered both as a tellurium(II) complex and as an organic pseudohalide.No intermolecular tellurium-oxygen contacts could be observed.
- Grung, Knut Eric,Roemming, Christian,Songstad, Jon
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p. 518 - 526
(2007/10/02)
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- AN EFFECTIVE CHLORINATING AGENT BENZYLTRIMETHYLAMMONIUM TETRACHLOROIODATE, BENZYLIC CHLORINATION OF ALKYLAROMATIC COMPOUNDS
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The reaction of alkylaromatic compounds with benzyltrimethylammonium tetrachloroiodate in carbon tetrachloride in the presence of AIBN under reflux for several hours gave α-chloro-substituted compounds in fairly good yields.
- Kajigaeshi, Shoji,Kakinami, Takaaki,Moriwaki, Masayuki,Tanaka, Toshio,Fujisaki, Shizuo
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p. 5783 - 5786
(2007/10/02)
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- Diphosphonic acid derivatives, processes for the preparation thereof and pharmaceutical compositions containing them
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Diphosphonate compounds, processes for their preparation and pharmaceutical compositions containing them and being useful for treating calcium metabolism disorders. The diphosphonates are of the formula STR1 wherein R1 and R2 are hydrogen, acyl or alkyl which can be substituted by aryl, R3 and R4 are hydrogen or alkyl or R3 and R4 together represent lower alkylene, R5 is a hydrogen atom or alkyl, X is a valency bond or alkylene, Y is a valency bond, alkylene or substituted alkylene, Z is hydrogen, hydroxyl or amino group optionally substituted by alkyl and n is 1, 2 or 3; and including the pharmacologically acceptable salts thereof.
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- Chlorination of Toluene and Substituted Toluenes by Trichloroisocyanuric Acid: A Kinetic Investigation
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The kinetics of chlorination of toluene, o-, m- and p-xylenes, m- and p-chlorotoluenes and m-nitrotoluene by trichloroisocyanuric acid (TCCA) in aqueous acetic acid in the presence of perchloric acid (HClO4) have been studied.The reaction is first order each in and .The reaction is insensitive towards change in .Increase in the percentage of acetic acid in the reaction medium retards the reaction rate.Various thermodynamic parameters have been evaluated.A suitable mechanism is postulated taking the observed kinetic data into consideration.
- Pati, Subas C.,Sarangi, Chintamani
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p. 745 - 747
(2007/10/02)
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- Hypertensive phenylalkylamines and salts thereof
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Compounds of the formula STR1 wherein R1 is hydrogen, --(CH2)n --R4 or --CO--R5, where n is 1 or 2, R4 is hydrogen, cyano or benzoyl, and R5 is hydrogen, lower alkoxy, benzyloxy, --CH2 --NH2, --CH(CH3)--NH2, --CH2 --NH--CH2 --C6 H5 or --CH(CH3)--NH--CH2 --C6 H5, R2 is hydrogen or methyl, and R3 is amino, nitro, --NH--CO--R6 or --NH--A--R7, where R6 is hydrogen, methyl, methoxy, ethoxy, methylthio or ethylthio, R7 is amino, methylamino or dimethylamino, and A is --CO-- or --SO2 --, provided, however, that R1 and R4 are other than hydrogen and R2 is other than hydrogen or methyl when R6 is hydrogen or methyl, and non-toxic, pharmacologically acceptable acid addition salts thereof; the compounds as well as their salts are useful as hypertensives.
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- Phenylalkylamines and salts thereof
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Compounds of the formula STR1 wherein R1 is hydrogen, --(CH2)n --R4 or --CO--R5, where n is 1 or 2, R4 is hydrogen, cyano or benzoyl, and R5 is hydrogen, lower alkoxy, benzyloxy, --CH2 --NH2, --CH(CH3)--NH2, --CH2 --NH--CH2 --C6 H5 or --CH(CH3)--NH--CH2 --C6 H5, R2 is hydrogen or methyl, and R3 is amino, nitro, --NH--CO--R6 or --NH--A--R7, where R6 is hydrogen, methyl, methoxy, ethoxy, methylthio or ethylthio, R7 is amino, methylamino or dimethylamino, and A is --CO-- or --SO2 --, and non-toxic, pharmacologically acceptable acid addition salts thereof; the compounds as well as their salts are useful as hypertensives.
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