- Double elimination protocol for synthesis of 5,6,11,12-tetradehydrodibenzo[a,e]cyclooctene
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A new method for constructing 5,6,11,12-tetradehydrodibenzo[a,e]-cyclooctene is described on the basis of one-pot double elimination protocol. The target molecule, which is the smallest cyclophane with alternate arylene-]ethynylene linkage, is synthesized in 61% yield through oxidative dimerization of ortho-(phenylsulfonylmethyl)-benzaldehyde. The initial carbon-carbon bond formation between sp3 carbons followed by stepwise conversion to sp2 and finally sp carbons bypasses the difficulty encountered in direct coupling of the sp carbon in the terminal acetylene. The mechanism of this process is discussed. The Wittig-Horner-type coupling is a key reaction employed for the carbon-carbon bond formation. Generation of (E)-vinylsulfone moiety in the first coupling between a-sulfonyl anion and aldehyde functions is crucial for the effective second coupling to complete the cyclization. The syn-elimination of the (E)-vinylsulfone moieties in the cyclized intermediate furnishes the acetylenic bonds.
- Orita, Akihiro,Hasegawa, Daiki,Nakano, Takehiko,Otera, Junzo
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Read Online
- DICYANSTYRYL BENZENE DERIVATIVES AND FLUORESCENT MATERIAL COMPRISING THE SAME
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The present invention refers to die [...] benzene derivatives represented by formula 1 are disclosed. The, head of the present invention die [...] benzene to yield fluorescent derivatives (Dicyanstyryl benzene) to minimize environmental pollution by reducing the drain diameter number fluorescent material can be [...] number can be improve. [Formula 1] (by machine translation)
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Paragraph 0227; 0232-0235
(2019/06/13)
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- Cu-Catalyzed Redox-Neutral Ring Cleavage of Cycloketone O-Acyl Oximes: Chemodivergent Access to Distal Oxygenated Nitriles
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A chemodivergent copper-catalyzed ring opening of cycloketone oximes via radical-mediated C-C bond cleavage under redox-neutral conditions is described. This method allows the divergent synthesis of γ- and δ-acyloxylated, alkoxylated, and hydroxylated nitriles while avoiding the use of toxic cyanide reagents. Moreover, these reactions proceed under very mild conditions with good functional group tolerance. Notably, ring-opening reactions of the less-strained substrate cyclopentanone oxime also proceeded well under the established conditions.
- Ai, Wenying,Liu, Yaqian,Wang, Qian,Lu, Zhonglin,Liu, Qiang
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p. 409 - 412
(2018/01/27)
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- Synthetic method of 2-cyanobenzyl bromide and analogues thereof
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The invention discloses a synthetic method of 2-cyanobenzyl bromide and analogues thereof. The synthetic method comprises the following steps: 1) using a compound I as a raw material, conducting reaction on the compound I and tert-butyldimethylsilyl chloride, and adding a first solvent and an acid-binding agent to generate a compound II; 2) dissolving the compound II into a second solvent, adding a palladium catalyst and a cyaniding agent, and carrying out a cyaniding reaction to generate a compound III; 3) dissolving the compound III into a third solvent without taking off protecting groups, and directly carrying out a bromination reaction under the effect of phosphorus tribromide so as to prepare a compound IV. The synthetic method is simple in process route and relatively high in product quality and yield.
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- Substituted 5,6,11,12-tetradehydrodibenzo[ a, e ]cyclooctenes: Syntheses, properties, and DFT studies of substituted sondheimer-wong diynes
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Highly strained cyclic acetylenes 5,6,11,12-tetradehydrodibenzo[a,e]cyclooctenes (Sondheimer-Wong diynes) having various substituents on their benzene rings were synthesized successfully by one-pot treatment of the corresponding formyl sulfones with diethyl chlorophosphate/lithium hexamethyldisilazide (LiHMDS) and then lithium diisopropylamide (LDA). When mixtures of two types of formyl sulfones bearing different substituents were subjected to this protocol, the unsymmetrically substituted Sondheimer-Wong diynes could be synthesized in a stepwise manner by isolation of the heterocoupled vinyl sulfone intermediates followed by their treatment with LDA. The UV-vis absorption spectra and cyclic voltammograms of the substituted Sondheimer-Wong diynes were recorded. The electronic effect of substituents on the diynes was investigated in their click reactions and nucleophilic and electrophilic additions.
- Xu, Feng,Peng, Lifen,Shinohara, Kenta,Morita, Takamoto,Yoshida, Suguru,Hosoya, Takamitsu,Orita, Akihiro,Otera, Junzo
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p. 11592 - 11608
(2015/01/09)
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- Synthesis, optical and nonlinear optical properties of new pyrazoline derivatives
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We report on synthesis and optical properties of new organic compounds based on substituted pyrazole ring. The investigated pyrazoline derivatives (PRDs) exhibit efficient broadband photoluminescence which covers nearly whole visible spectrum. The experimental results are compared to quantum chemical calculations. Amplified spontaneous emission and photodegradation measurements were performed for hybrid systems based on selected PRDs doped into poly(methyl methacrylate) matrix proving the potential utility of such systems in lasing applications. Two-photon absorption (TPA) properties were characterized by the femtosecond Z-scan technique.
- Mysliwiec,Szukalski,Sznitko,Miniewicz,Haupa,Zygadlo,Matczyszyn,Olesiak-Banska,Samoc
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- Rhodium(iii)-catalyzed olefinic C-H alkynylation of enamides at room temperature
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Rh(iii)-catalyzed C-H olefinic alkynylation of enamides for the stereospecific construction of synthetically useful Z-type enynamides is reported. This protocol displays good functionality tolerance and operational simplicity thus providing an alternative synthetic opportunity for the ease of access to specific 1,3-enyne derivatives.
- Feng, Chao,Feng, Daming,Loh, Teck-Peng
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supporting information
p. 9865 - 9868
(2014/08/18)
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- Photochemical and thermal intramolecular 1,3-dipolar cycloaddition reactions of new o-stilbenemethylene-3-sydnones and their synthesis
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New trans-and cis-o-stilbene-methylene-sydnones 3a,b were synthesized by transforming the trans-and cis-o-aminomethylstilbene derivative, obtained by reduction of corresponding o-cyano derivatives, into glycine ester derivatives (43 and 31% yield) followed by hydrolysis (90 and 96% yield), nitrosation and ring closure with acetic acid anhydride (30 and 40% yield). The products were submitted to photochemical and thermal intramolecular [3 + 2] cycloadditions to afford diverse heteropolycyclic compounds. Photochemical reactions afforded cis-3-(4-methylphenyl)-3a,8-dihydro-3H-pyrazolo[5,1-a]isoindole (11, 12.5% yield) and trans-3-(4-methylphenyl)-3a,8-dihydro-3H-pyrazolo[5,1-a]isoindole (12, 5% yield). Thermal reactions afforded 3-(4-methylphenyl)-3,3a,8,8a- tetrahydroindeno[2,1-c]pyrazole (14, 50% yield) and 11-(4-methylphenyl)-9,10- diazatricyclo[7.2.1.02,7]dodeca-2,4,6,10-tetraene (15, 22% yield).
- Butkovic, Kristina,Marinic, Zeljko,Molcanov, Kresimir,Kojic-Prodic, Biserka,Sindler-Kulyk, Marija
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supporting information; experimental part
p. 1663 - 1670
(2012/02/04)
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- (1,4-DIAZA-BICYCLO[3.2.2]NON-6-EN-4-YL)-HETEROCYCLYL-METHANONE LIGANDS FOR NICOTINIC ACETYLCHOLINE RECEPTORS, USEFUL FOR THE TREATMENT OF DISEASE
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The present invention relates generally to the field of ligands for nicotinic acetylcholine receptors (nACh receptors), activation of nACh receptors, and the treatment of disease conditions associated with defective or malfunctioning nicotinic acetylcholine receptors, especially of the brain. Further, this invention relates to novel compounds, which act as ligands for the a7 nACh receptor subtype, methods of preparing such compounds, compositions containing such compounds, and methods of use thereof. The novel compounds include compounds of formula I: (I) wherein X, R1, and R2 are as herein defined.
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Page/Page column 61; 62
(2009/05/30)
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- 4-Phenylpyrrolo[3,4-c]carbazole-1,3(2H,6H)-dione inhibitors of the checkpoint kinase Wee1. structure-activity relationships for chromophore modification and phenyl ring substitution
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High-throughput screening has identified a novel class of inhibitors of the checkpoint kinase Wee1, which have potential for use in cancer chemotherapy. These inhibitors are based on a 4-phenylpyrrolo[3,4-c]-carbazole-1,3(2H,6H)- dione template and have been shown by X-ray crystallography to bind at the ATP site of the enzyme. An extensive study of the effects of substitution around this template has been carried out, which has identified substituents which lead to improvements in potency and selectivity for Wee1. While retention of the maleimide ring and pendant 4-phenyl group is necessary for potency, replacement of the carbazole nitrogen by oxygen is well tolerated and results in improved Wee1 selectivity against the related checkpoint kinase Chk1. Wee1 potency and selectivity are also enhanced by the incorporation of lipophilic functionality at the 2′-position of the 4-phenyl ring, and Wee1 selectivity against Chk1 is favored by C3-C5 alkyl substitution of the carbazole nitrogen. These studies provide a basis for the design of active analogues of the pyrrolocarbazole lead with improved physical properties.
- Palmer, Brian D.,Thompson, Andrew M.,Booth, R. John,Dobrusin, Ellen M.,Kraker, Alan J.,Lee, Ho H.,Lunney, Elizabeth A.,Mitchell, Lorna H.,Ortwine, Daniel F.,Smaill, Jeff B.,Swan, Leesa M.,Denny, William A.
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p. 4896 - 4911
(2007/10/03)
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- A convenient procedure for palladium catalyzed cyanation using a unique bidentate phosphorus ligand
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A palladium complex bearing 1,2-diphenyl-3,4-diphosphinidenecyclobutene ligand (DPCB) has been used to facilitate the catalytic cyanation of aryl bromides. A series of substituted benzonitriles was prepared in good to high yields by the treatment of the corresponding aryl bromides with Zn(CN) 2 in N-methyl-2-pyrrolidone in the presence of 2-4 mol % catalyst at 100°C for 16 h.
- Jensen, Rader S.,Gajare, Anil S.,Toyota, Kozo,Yoshifuji, Masaaki,Ozawa, Fumiyuki
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p. 8645 - 8647
(2007/10/03)
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- Catalytic processes of oxidation by hydrogen peroxide in the presence of Br2 or HBr. Mechanism and synthetic applications
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The mechanism and the synthetic applications for the oxidation of alcohols, ethers, and aldehydes by H2O2 catalyzed by Bf2 or Br- in a liquid two-phase system (aqueous and organic) are reported. Aliphatic and benzylic primary alcohols and ethers show an opposite behavior, which has been rationalized on the ground of the different electronic configurations of the intermediate alkyl (π-type) and acyl (σ-type) radicals and their influence on enthalpic and polar effects. A two-phase system is particularly useful also for an efficient benzylic bromination by Br2 or Br-; the substitution of the benzyl bromide by OH, OR, and OCOR regenerates Br-, which can be recycled. The evaluation of the relative reactivities of the involved substrates and intermediates has allowed to develop a variety of simple, facile, convenient, and selective syntheses of alcohols, aldehydes, ketones, esters, and benzyl bromides, which fulfill the conditions for practical applications.
- Amati, Alessandro,Dosualdo, Gabriele,Zhao, Lihua,Bravo, Anna,Fontana, Francesca,Minisci, Francesco,Bjorsvik, Hans-Rene
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p. 261 - 269
(2013/09/08)
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- Intramolecular Photocycloaddition of the C=C Double Bond to the CN Triple Bond Resulting in the Formation of a Novel Cyclic System
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Irradiation of a bichromophoric 1-(o-cyanobenzyloxy)-2-(p-methoxyphenyl)-2-butene (1a) in cyclohexane gave an isoquinoline derivative, 8-methoxy-6-methyl-11,13-dihydrobenzoxepinoisoquinoline (2a). The structure was determined by X-ray analysis. The formation of 2a can be accounted for by the initial cycloaddition of 1a in the excited singlet state between the C=C double bond and CN triple bond, followed by cleavage of the resulting azetine ring and recyclization.
- Sakuragi, Hirochika,Koyama, Toshiya,Sakurazawa, Mamoru,Yasui, Norimichi,Tokumaru, Katsumi,Ueno, Katsuhiko
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p. 1769 - 1772
(2007/10/02)
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- Diarylstrylquinoline diacids and pharmaceutical compositions thereof
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Compounds having the formula: STR1 are leukotriene antagonists and inhibitors of leukotriene biosynthesis. These compounds are useful as anti-asthmatic, anti-allergic, anti-inflammatory, and cytoprotective agents.
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