- Synthesis of Benzothienobenzofurans via Annulation of Electrophilic Benzothiophenes with Phenols
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We have developed a metal-free, mild, and green synthetic route toward benzothieno[3,2-b]benzofurans by the annulation of 3-nitrobenzothiophene with phenols. The reaction was found to be general with a range of substituted phenols. In addition, we could extend the methodology for the synthesis of pentacenes and could demonstrate the synthesis in gram-scale. Moreover, we extended the strategy for the synthesis of benzothieno[2,3-b]benzofurans by starting from 2-nitrobenzothiophenes.
- Krishnan, Akhil R.,Babu, Sheba Ann,Nitha,Krishnan, Jagadeesh,John, Jubi
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Read Online
- Facile removal of tosyl chloride from tosylates using cellulosic materials, e.g., filter paper
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Excess tosyl chloride used in the tosylation of alcohols is quickly and easily removed by reacting it with cellulosic materials, e.g., filter paper, and filtering.
- Schoonover, Daniel V.,Gibson, Harry W.
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Read Online
- The Synthesis and Catalytic Activity of New Mixed NHC-Phosphite Nickel(0) Complexes
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Herein we describe the synthesis and isolation of the first low-valent NHC-phosphite nickel complexes of general formula Ni(NHC)[P(OAr)3]2. These three-coordinate Ni(0) compounds were fully characterized, including by X-ray crystallography that highlighted their trigonal planar geometry. The representative complex Ni(IMes)[P(OPh)3]2 was used to show that a phosphite ligand is readily substituted in the presence of an aldehyde or nitrile. These stoichiometric studies then led to an investigation of their catalytic properties in the Suzuki-Miyaura cross-coupling reactions between aryl tosylates and aryl boronic acids, a first for such a NHC-Ni catalyst. Finally, mechanistic investigations led to the isolation of a well-defined oxidative addition product.
- Dorta, Reto,Duczynski, Jeremy,Moggach, Stephen A.,Sobolev, Alexandre N.,Stewart, Scott G.
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supporting information
(2020/01/21)
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- Transition-Metal-Free and Visible-Light-Mediated Desulfonylation and Dehalogenation Reactions: Hantzsch Ester Anion as Electron and Hydrogen Atom Donor
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Novel approaches for N- and O-desulfonylation under room temperature (rt) and transition-metal-free conditions have been developed. The first methodology involves the transformation of a variety of N-sulfonyl heterocycles and phenyl benzenesulfonates to the corresponding desulfonylated products in good to excellent yields using only KOtBu in dimethyl sulfoxide (DMSO) at rt. Alternately, a visible light method has been used for deprotection of N-methyl-N-arylsulfonamides with Hantzsch ester (HE) anion serving as the visible-light-absorbing reagent and electron and hydrogen atom donor to promote the desulfonylation reaction. The HE anion can be easily prepared in situ by reaction of the corresponding HE with KOtBu in DMSO at rt. Both protocols were further explored in terms of synthetic scope as well as mechanistic aspects to rationalize key features of desulfonylation processes. Furthermore, the HE anion induces reductive dehalogenation reaction of aryl halides under visible light irradiation.
- Heredia, Micaela D.,Guerra, Walter D.,Barolo, Silvia M.,Fornasier, Santiago J.,Rossi, Roberto A.,Budén, Mariá E.
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supporting information
p. 13481 - 13494
(2020/12/15)
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- Palladium-Catalyzed Cyclobutanation of Aryl Sulfonates through both C-O and C-H Cleavage
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A palladium-catalyzed cyclobutanation of aryl sulfonates with strained alkenes has been developed. The methodology is featured to achieve the cleavage of both C-O and C-H bonds of phenol derivatives in one pot. Under the reaction conditions, in addition t
- Zhang, Liangwei,Liu, Long,Huang, Tianzeng,Dong, Qizhi,Chen, Tieqiao,Chen, Tieqiao
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p. 2189 - 2196
(2020/06/05)
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- Electron Donor-Acceptor Complex Enabled Decarboxylative Sulfonylation of Cinnamic Acids under Visible-Light Irradiation
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Visible-light-induced decarboxylative sulfonylation of cinnamic acids with aryl sulfonate phenol esters enabled by the electron donor-acceptor complex is developed. The method offers a mild and green approach for the synthesis of vinyl sulfones with excellent functional group compatibility under photocatalyst and oxidant-free conditions.
- Ge, Qian-Qian,Qian, Jia-Sheng,Xuan, Jun
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p. 8691 - 8701
(2019/08/30)
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- Copper-Catalyzed C-S Bond Formation via the Cleavage of C-O Bonds in the Presence of S8 as the Sulfur Source
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Useful and applicable methods for one-pot and odorless synthesis of unsymmetrical and symmetrical diaryl sulfides via C-O bond activation are presented. First, a new efficient procedure for the synthesis of unsymmetrical sulfides using the cross-coupling reaction of phenolic esters such as acetates, tosylates, and triflates and with arylboronic acid or triphenyltin chloride as the coupling partners is reported. Depending on the reaction, S 8 /KF or S 8 /NaO t -Bu system is found to be an effective source of sulfur in the presence of copper salts and in poly(ethylene glycol) as a green solvent. Then, the synthesis of symmetrical diaryl sulfides from phenolic compounds by using S 8 as the sulfur source and NaO t -Bu in anhydrous DMF at 120 °C under N 2 is described. By these protocols, the synthesis of a variety of unsymmetrical and symmetrical sulfides become easier than the available protocols in which thiols and aryl halides are directly used for the preparation of the sulfides.
- Rostami, Abed,Rostami, Amin,Ghaderi, Arash,Gholinejad, Mohammad,Gheisarzadeh, Sajedeh
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p. 5025 - 5038
(2017/10/06)
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- Copper-Catalyzed Regioselective C-H Sulfonyloxylation of Electron-Rich Arenes with p-Toluenesulfonic Acid and Sulfonyloxylation of Aryl(mesityl)iodonium Sulfonates
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Copper-catalyzed regioselective C-H sulfonyloxylation of electron-rich arenes with p-toluenesulfonic acid has been developed. Electron-rich benzene derivatives and heteroarenes can undergo this C-H sulfonyloxylation reaction to generate aryl tosylates. Furthermore, sulfonyloxylation of aryl(mesityl)iodonium sulfonates has also been investigated. Both aryl(mesityl)iodonium tosylates and triflates can react smoothly to get aryl sulfonates. The formed aryl sulfonates can be converted to phenols, as well as used as good partners of cross-coupling reactions.
- Huang, He,Wu, Yang,Zhang, Wen,Feng, Chun,Wang, Bi-Qin,Cai, Wan-Fei,Hu, Ping,Zhao, Ke-Qing,Xiang, Shi-Kai
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p. 3094 - 3101
(2017/03/23)
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- Direct Carboxylation of Aryl Tosylates by CO2 Catalyzed by in situ-Generated Ni0
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A novel Ni0-catalyzed carboxylation of aryl tosylates with carbon dioxide has been achieved under moderate temperatures and atmospheric pressure. In this procedure, the active Ni0 species is generated in situ by simply mixing the Ni0 precatalyst [NiBr2(bipy)] with an excess of manganese metal. This approach requires neither a glove-box nor the tedious preparation of sophisticated intermediate organometallic derivatives. This mild, convenient, and user-friendly process is successfully applied to the valorization of carbon dioxide and the synthesis of versatile reactants with broad tolerance of substituents.
- Rebih, Fatima,Andreini, Manuel,Moncomble, Aurlien,Harrison-Marchand, Anne,Maddaluno, Jacques,Durandetti, Muriel
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supporting information
p. 3758 - 3763
(2016/03/08)
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- Rational Design of Potent and Selective Inhibitors of an Epoxide Hydrolase Virulence Factor from Pseudomonas aeruginosa
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The virulence factor cystic fibrosis transmembrane conductance regulator (CFTR) inhibitory factor (Cif) is secreted by Pseudomonas aeruginosa and is the founding member of a distinct class of epoxide hydrolases (EHs) that triggers the catalysis-dependent
- Kitamura, Seiya,Hvorecny, Kelli L.,Niu, Jun,Hammock, Bruce D.,Madden, Dean R.,Morisseau, Christophe
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supporting information
p. 4790 - 4799
(2016/06/13)
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- Gold(I)-Catalyzed N-Desulfonylative Amination versus N-to-O 1,5-Sulfonyl Migration: A Versatile Approach to 1-Azabicycloalkanes
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Valuable 1-azabicycloalkane derivatives have been synthesized through a novel gold(I)-catalyzed desulfonylative cyclization strategy. An ammoniumation reaction of ynones substituted at the 1-position with an N-sulfonyl azacycle took place in the presence of a gold cation by intramolecular cyclization of the disubstituted sulfonamide moiety onto the triple bond. Depending on the size of the heterocyclic ring and substitution of the substrates, two unprecedented forms of nucleophilic attack on the sulfonyl group were exploited, that is, a N-desulfonylation in the presence of an external protic O nucleophile (37–87 %, 10 examples) and a unique N-to-O 1,5-sulfonyl migration (60–98 %, 9 examples).
- Miaskiewicz, Solène,Gaillard, Boris,Kern, Nicolas,Weibel, Jean-Marc,Pale, Patrick,Blanc, Aurélien
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p. 9088 - 9092
(2016/07/26)
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- Chromatography-Free and Eco-Friendly Synthesis of Aryl Tosylates and Mesylates
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Two chromatography-free and eco-friendly protocols have been developed to synthesize aryl tosylates and mesylates by the tosylation and mesylation of the corresponding hydroxyarenes, respectively. These protocols are superior to other known ones regarding
- Lei, Xiangyang,Jalla, Anusha,Abou Shama, Mhd A.,Stafford, Jamie M.,Cao, Billy
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supporting information
p. 2578 - 2585
(2015/09/01)
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- Aryl tosylates as non-ionic photoacid generators (PAGs): Photochemistry and applications in cationic photopolymerizations
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The irradiation of various substituted aryl tosylates was investigated in a solution and homolysis of the ArO-SO2C6H4CH3 bond was the path exclusively observed. The corresponding phenols and photo-Fries adducts were obtained and p-toluenesulfinic and p-toluenesulfonic acids were liberated. The nature and amount of the acid photoreleased were tuned by changing the reaction conditions and the nature and position of the aromatic substituents. In deaerated solutions p-toluenesulfinic acid was formed exclusively, whereas under oxygenated conditions the stronger p-toluenesulfonic acid was released, as shown by HPLC ion chromatography analyses. ArO-S bond photocleavage takes place from the singlet state, as confirmed by laser flash photolysis experiments, and competitive intersystem crossing can make the aryl tosylate unreactive when a nitro group is present. The application of these aryl tosylates as non-ionic photoacid generators (PAGs) in hybrid organic/inorganic sol-gel photoresists has been explored.
- Torti, Edoardo,Della Giustina, Gioia,Protti, Stefano,Merli, Daniele,Brusatin, Giovanna,Fagnoni, Maurizio
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p. 33239 - 33248
(2015/04/27)
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- Dimerization of Aryl Sulfonates by in situ Generated Nickel(0)
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A mild and user-friendly nickel-catalyzed method for the reductive homocoupling of aromatic tosylates is presented. The reaction proceeds between room temperature and 60 °C, with stable substrates (ArOTs) easily prepared from inexpensive and commercially available phenols or naphthols. It relies on a catalytic amount (10 mol%) of a robust catalyst (NiBr2bipy) that does not require the preparation of sensitive organometallic intermediates. Yields are good to excellent.
- Maddaluno, Jacques,Durandetti, Muriel
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supporting information
p. 2385 - 2388
(2015/10/19)
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- REGIOREGULAR COPOLYMERS AND METHODS FOR MAKING SAME
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Methods for producing regioregular poly(aryl ethynyl)-poly(aryl vinyl) and monomers for preparing the regioregular poly(aryl ethynyl)-poly(aryl vinyl) polymers are described herein. Regioregular poly(aryl ethynyl)-poly(aryl vinyl) are useful for electronics, among other things.
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Paragraph 0033
(2015/04/15)
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- Aminocarbonylation of Aryl Tosylates to Carboxamides
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The palladium - catalyzed aminocarbonylation of aryl tosylates with amines is reported. Suitable conditions were identified by high throughput reaction screening and then further optimized. The substrate scope of the reaction with respect to the aryl tosylate component and the amine component are reported. Competitive aminolysis of the aryl tosylates to afford the amine toluenesulfonamides and the phenol was not observed.
- Chung, Seungwon,Sach, Neal,Choi, Chulho,Yang, Xiaojing,Drozda, Susan E.,Singer, Robert A.,Wright, Stephen W.
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supporting information
p. 2848 - 2851
(2015/06/16)
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- Controlled regioregularity in oligo(2-methoxy-5-(2′-ethylhexyloxy)-1, 4-phenylenevinylenes
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A series of three pentameric derivatives of 2-methoxy-5-(2′- ethylhexyloxy)-p-phenylenevinylenes (2-4), with varying degrees of side chain regioregularity, was prepared. The oligomerization chemistry was carried out using repetitive Horner-Wadsworth-Emmon
- Zhu, Xinju,Plunkett, Kyle N.
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p. 7093 - 7102
(2014/08/18)
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- Suzuki-Miyaura coupling of aryl sulfonates with arylboronic acids using a morpholine-Pd(OAc)2 catalyst system
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We report a new catalyst system, a morpholine-Pd(OAc)2 complex, for Suzuki-Miyaura coupling of aryl tosylates or mesylates with arylboronic acids to give biaryl compounds. The morpholine-Pd(OAc)2 catalyst system is proposed to be a precursor of the catalytically active species in the coupling reaction. Aryl chlorides and aryl triflates can also be used in this coupling reaction. Altogether, 22 biaryl compounds were obtained using this catalyst system. We report a new catalyst system, a morpholine-Pd(OAc) 2 complex, for Suzuki-Miyaura coupling of aryl tosylates or mesylates with arylboronic acids to give biaryl compounds. The morpholine-Pd(OAc) 2 catalyst system is proposed to be a precursor of the catalytically active species in the coupling reaction. Copyright
- Abe, Taichi,Mino, Takashi,Watanabe, Kohei,Yagishita, Fumitoshi,Sakamoto, Masami
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p. 3909 - 3916
(2014/06/24)
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- Copper-catalysed coupling of aryl tosylates with sodium arylsulfinates
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Diaryl sulfones derivatives were easily synthesised from aryl tosylates and sodium arylsulfinates in high yields using [Cu(CH3CN)4]PF6 as catalyst. The transformation is efficient, simple and the starting materials are readily available.
- Wang, Chunjie,Zhang, Hui,Li, Zhiwei,Wang, Ziyun
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p. 639 - 642
(2015/02/02)
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- One-pot tandem reactions for direct conversion of thiols and disulfides to sulfonic esters, alcohols to bis(indolyl)methanes and synthesis of pyrroles catalyzed by N-chloro reagents
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A convenient synthesis of sulfonic esters from thiols and disulfides has been described. In situ preparation of sulfonyl chlorides from thiols is accomplished by oxidation with Chloramin-T, tetra-butylammonium chloride (t-Bu4NCl) and water. The sulfonyl chlorides are then further allowed to react with phenol derivatives in the same reaction vessel. Also, a facile synthesis of bis(indolyl)methanes from alcohols using TCCA/KBr/wet-SiO2, and N-substituted pyrroles by reaction of hexane-2,5-dione with primary amines has been accomplished under mild condition with excellent yields.
- Veisi, Hojat,Ataee, Meral,Fatolahi, Leila,Lotfi, Shahram
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p. 111 - 117
(2013/07/26)
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- Iron-catalyzed cross-coupling reactions of alkyl grignards with aryl sulfamates and tosylates
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The iron-catalyzed cross-coupling of aryl sulfamates and tosylates has been achieved with primary and secondary alkyl Grignards. This study of iron-catalyzed cross-coupling reactions also examines the isomerization and β-hydride elimination problems that are associated with the use of isopropyl nucleophiles. While a variety of iron sources were competent in the reaction, the use of FeF3·3H2O was critical to minimize nucleophile isomerization.
- Agrawal, Toolika,Cook, Silas P.
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supporting information
p. 96 - 99
(2013/03/28)
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- One-pot tandem reactions for direct conversion of thiols and disulfides to sulfonic esters, and Paal-Knorr synthesis of pyrrole derivatives catalyzed by TCCA
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A convenient synthesis of sulfonic esters from thiols and disulfides is described. In situ preparation of sulfonyl chlorides from thiols is accomplished by oxidation with trichloroisocyanuric acid (TCCA), tetra-butylammonium chloride (t-Bu4NCl), and water. The sulfonyl chlorides are then further allowed to react with phenol derivatives in the same reaction vessel. Also, a facile synthesis of N-substituted pyrroles by the reaction of hexane-2,5-dione with primary amines has been accomplished using TCCA as a catalyst under mild condition with excellent yields.
- Hemmati, Saba,Mojtahedi, Mohammad Majid,Abaee, Mohammad Saeed,Vafajoo, Zahra,Saremi, Shokufe Ghahri,Noroozi, Mohammad,Sedrpoushan, Alireza,Ataee, Meral
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p. 347 - 357
(2013/09/23)
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- Synthesis of sulfonamides and sulfonic esters via reaction of amines and phenols with thiols using H2O2-POCl3 system
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Phosphorus oxychloride efficiently promoted the synthesis of sulfonamides and sulfonic esters from thiols with hydrogen peroxide in the presence of Amberlite IRA-400 (OH-). This method has been applied to a variety of substrates including nucleophilic and sterically hindered amines, and also phenols with excellent yields of sulfonamides and sulfonic esters. In most cases these reactions are highly selective, simple, and clean, affording products in excellent yields and high purity.
- Bahrami, Kiumars,Khodaei, Mohammad M.,Abbasi, Jamshid
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supporting information; experimental part
p. 5095 - 5101
(2012/07/28)
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- Cs2CO3 catalyzed rapid and efficient conversion of amines into sulfonamides; Alcohols and phenols into sulfonic esters
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A simple and efficient method has been developed for the sulfonylation of several amines, alcohols, and phenols by p-toluenesulphonylchloride (p-TsCl) in the presence of catalytic amount of Cs2CO3 at 25C to obtain sulfonamides and sulfonic esters in very good yields. Cs2CO3 has been found to be highly efficient catalyst. Taylor & Francis Group, LLC.
- Reddy, M. B. Madhusudana,Pasha
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experimental part
p. 1867 - 1875
(2011/10/11)
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- Decarboxylative cross-coupling of aryl tosylates with aromatic carboxylate salts
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(Figure Presented) A bimetallic copper/palladium catalyst system is disclosed that enables the use of tosylates as carbon electrophiles in decarboxylative coupling reactions. A variety of aromatic carboxylate salts, regardless of their substitution pattern, have been coupled with these inexpensive and readily available electrophiles to give the corresponding biaryl compounds in good yields (see scheme).
- Goossen, Luksa J.,Rodriguez, Nuria,Lange, Paul P.,Linder, Christophe
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supporting information; experimental part
p. 1111 - 1114
(2010/04/29)
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- Neopentylglycolborylation of aryl mesylates and tosylates catalyzed by Ni-based mixed-ligand systems activated with Zn
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(Chemical Presented) The mixed-ligand system NiCl2(dppp)/dppf is shown to be an effective catalyst for the neopentylglycolborylation of ortho-, meta-, and para-substituted electron-rich and electrondeficient aryl mesylates and tosylates. The ad
- Wilson, Daniela A.,Wilson, Christopher J.,Moldoveanu, Costel,Resmerita, Ana-Maria,Corcoran, Patrick,Hoang, Lisa M.,Rosen, Brad M.,Percec, Virgil
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supporting information; experimental part
p. 1800 - 1801
(2010/04/24)
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- Highly efficient Pd-catalyzed cyanation of aryl chlorides and arenesulfonates with potassium ferrocyanide in aqueous media
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A highly improved Pd-catalyzed cyanation of aryl chlorides to corresponding benzonitriles was demonstrated in aqueous media. Moreover, Pd-catalyzed cyanation of aryl tosylates and benzenesulfonates with K4[Fe(CN) 6] was developed under the similar conditions, which extended application scope of the cyanation. Graphical Abstract: [Figure not available: see fulltext.]
- Zhang, Junli,Chen, Xiaorong,Hu, Tongjie,Zhang, Yuan,Xu, Kunling,Yu, Yanpeng,Huang, Jun
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experimental part
p. 56 - 60
(2011/01/12)
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- N-heterocyclic carbene derived Nickel-Pincer complexes: Efficient and applicable catalysts for Suzuki-Miyaura coupling reactions of aryl/alkenyl tosylates and mesylates
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Catalytic activities of NHC-derived nickel-pincer complexes for the Suzuki-Miyaura coupling reactions of aryl/alkenyl to- sylates and mesylates are described. In the presence of a catalytic amount of nickelacycle 1a, a wide array of tosylates and mesylates reacted with several aryl- and alkenylboronic acids to afford the coupling products, generally in high yields. Fine tuning of the reaction conditions for each class of electrophiles was achieved only by choosing the appropriate reaction medium (DME for tosylates, dioxane for mesylates).
- Kuroda, Jun-Ichi,Inamoto, Kiyofumi,Hiroya, Kou,Doi, Takayuki
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experimental part
p. 2251 - 2261
(2009/08/09)
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- A simple and efficient method for sulfonylation of amines, alcohols and phenols with cupric oxide under mild conditions
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Cupric Oxide efficiently catalyzed the synthesis of sulfonamides and sulfonic esters. This method has been applied to a variety of substrates including nucleophilic and sterically-hindered amines, alcohols and phenols with excellent yields of sulfonamides and sulfonic esters. The remarkable selectivity under mild and neutral conditions of this commercially available inexpensive catalyst is an attractive feature of this method.
- Meshram,Patil, Vishvanath D.
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scheme or table
p. 1117 - 1121
(2009/05/27)
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- Palladium-catalyzed amination of aryl and heteroaryl tosylates at room temperature
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Mild palladium-catalyzed aminations of aryl tosylates and the first aminations of heteroaryl tosylates are described. In the presence of the combination of L2Pd(0) (L = P(o-tol)3) and the hindered Josiphos ligand CyPF-t-Bu, a variety of primary alkylamines and arylamines react with both aryl and heteroaryl tosylates at room temperature to form the corresponding secondary arylamines in high yields with complete selectivity for the monoarylamine. These reactions at room temperature occur in many cases with catalyst loadings of 0.1 mol % and 0.01 mol % in one case, constituting the most efficient aminations of aryl tosylates by nearly 2 orders of magnitude. This catalyst is made practical by the development of a convenient method to synthesize the L2Pd(0) precursor. This complex is stable to air as a solid. In contrast to conventional relative rates for reactions of aryl sulfonates, the reactions of aryl tosylates are faster than parallel reactions of aryl triflates, and the reactions of aryl tosylates are faster than parallel or competitive reactions of aryl chlorides. Copyright
- Ogata, Tokutaro,Hartwig, John F.
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supporting information; experimental part
p. 13848 - 13849
(2009/02/07)
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- How the π conjugation length affects the fluorescence emission efficiency
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How the π conjugation length affects the fluorescence emission efficiency is elucidated by examination of the theoretical and experimental relationship between absolute quantum yield (Φf) and magnitude (Aπ) of the π conjugation lengt
- Yamaguchi, Yoshihiro,Matsubara, Yoshio,Ochi, Takanori,Wakamiya, Tateaki,Yoshida, Zen-Ichi
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supporting information; experimental part
p. 13867 - 13869
(2009/02/07)
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- Mild and efficient indium metal catalyzed synthesis of sulfonamides and sulfonic esters
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A facile and efficient method for synthesizing sulfonamides was developed using a catalytic amount of indium metal. A wide range of sulfonamides were synthesized in excellent yields using the new process. The method showed a generality for substrates including less nucleophilic and sterically hindered anilines, and it is also applicable for preparing sulfonic esters from sulfonyl chlorides and alcohols. Georg Thieme Verlag Stuttgart.
- Kim, Joong-Gon,Doo, Ok Jang
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p. 2501 - 2504
(2008/02/13)
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- A new preparative method of aryl sulfonate esters by using cyclic organobismuth reagents
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A new method for the preparation of aryl sulfonate esters by using a cyclic pentavalent bismuth is described. Aryl sulfonate esters are formed in good to high yields by treating 10-arylphenothiabismine 5,5-dioxides, m-chloroperoxybenzoicacid (m-CPBA)and various sulfonic acids in dichloromethane.
- Sakurai, Naoto,Mukaiyama, Teruaki
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p. 771 - 790
(2008/09/18)
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- Rigid molecular architectures that comprise a 1,3,5-trisubstituted benzene core and three oligoaryleneethynylene arms: Light-emitting characteristics and π conjugation between the arms
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In view of increasing interest in light-emitting materials, we have investigated the light-emitting characteristics and occurrence of conjugation between arms of star-shaped rigid molecules that comprise a 1,3,5-triethynylbenzene core and methoxy group-su
- Yamaguchi, Yoshihiro,Ochi, Takanori,Miyamura, Satoshi,Tanaka, Takahiro,Kobayashi, Shigeya,Wakamiya, Tateaki,Matsubara, Yoshio,Yoshida, Zen-Ichi
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p. 4504 - 4505
(2007/10/03)
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- Light-emitting efficiency tuning of rod-shaped π conjugated systems by donor and acceptor groups
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In view of the increasing importance of highly efficient light-emitting materials in chemistry, biological science, and materials science, we investigated the light-emitting efficiency tuning of rod-shaped oligo(p-phenylene ethynylene)s (OPEs, trimeric to pentameric systems) by donor and acceptor groups, so that they emit the very intense fluorescence (Φf ≈ 1.0, log ε ≈ 5) at 460 nm as the desired wavelength region. This goal was achieved by side modification by MeO (donor) groups and end modification by a CN-substituted benzene ring or CF3-substituted pyridine ring (acceptor) of tetrameric p-phenylene ethynylene rod-shaped molecules (Φf = 0.96, λem = 458 nm, log ε = 4.96 for the former and Φf = 0.99, λem = 459 nm, log ε = 4.92 for the latter). The high Φf values for 11 and 12 are interpreted in terms of kr (radiative rate constant) and kd (radiationless rate constant). The linear relationship with a positive slope between Φf and the Hammett σ constant was found for the first time. It is found that kd rather than kr varies with σp-X. The photophysical properties (Φf, λem, λabs, log ε) were not so altered with the solvent polarity, which could be explained by the dipole moments in the excited and ground states. The results would be valuable for the molecular design of highly efficient light-emitting materials. Copyright
- Yamaguchi, Yoshihiro,Tanaka, Takahiro,Kobayashi, Shigeya,Wakamiya, Tateaki,Matsubara, Yoshio,Yoshida, Zen-Ichi
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p. 9332 - 9333
(2007/10/03)
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- Banana-shaped oligo(aryleneethynylene)s: Synthesis and light-emitting characteristics
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(Chemical Equation Presented) Pick of the bunch: Banana-shaped molecules 1 and 2 containing dimethoxybenzene and pyridine units are highly efficient emitters of violet light despite the interruption of the π conjugation because of meta substitution. The c
- Yamaguchi, Yoshihiro,Kobayashi, Shigeya,Wakamiya, Tateaki,Matsubara, Yoshio,Yoshida, Zen-Ichi
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p. 7040 - 7044
(2007/10/03)
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- Room-Temperature Ni(0)-Catalyzed Cross-Coupling Reactions of Aryl Arenesulfonates with Arylboronic Acids
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Room-temperature Ni(0)-catalyzed cross-coupling reactions of aryl arenesulfonates with arylboronic acids are described. The Ni(0) catalyst, derived from Ni(COD)2 and PCy3, proved to be a general one for the Suzuki?Miyaura cross-coupling of a variety of aryl arenesulfonates. The mild reaction condition, the readily availability of the catalyst, and excellent coupling yields make aryl arenesulfonates potentially useful substrates in organic synthesis. Copyright
- Tang, Zhen-Yu,Hu, Qiao-Sheng
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p. 3058 - 3059
(2007/10/03)
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- Selected sulfonyl compounds as anticancer/antimalarial agents
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The synthesis and biological testing of a series of sulfonyl phenols and sulfonyl aryl methyl ethers has revealed that p-methoxyphenyl p-toluenesulfonate is a very selective and effective antimalarial agent which shows pronounced activity against human skin cancer cells. Application of a counter-attack strategy permits the direct preparation of the requisite tosylate ether from the bis(tosylate) of dihydroquinone.
- Langler, Richard F.,Paddock, Robert L.,Thompson, David B.,Crandall, Ian,Ciach, Michelle,Kain, Kevin C.
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p. 1127 - 1133
(2007/10/03)
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- NiCl2(PCy3)2: A simple and efficient catalyst precursor for the Suzuki cross-coupling of aryl tosylates and arylboronic acids
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matrix presented NiCl2(PCy3)2 associated with PCy3 promotes the selective cross-coupling of aryltosylates with arylboronic acids under relatively mild reaction conditions, and a variety of functional groups are tolerated in both arenes. This is one of the simplest and most efficient experimental procedures for the coupling of arylboronic acids with aryl tosylates reported to date.
- Zim, Danilo,Lando, Vanusa R.,Dupont, Jairton,Monteiro, Adriano L.
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p. 3049 - 3051
(2007/10/03)
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- Synthesis of Bromo-iodo-hydroquinone Monoalkyl Ethers
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Two methods for the preparation of 2-bromo-5-iodo-p-alkoxyphenols and the isomeric 5-bromo-2-iodo-p-alkoxyphenols are reported in detail.In both cases the key to successful synthesis is the use of the difference in ortho-directing power of phenols, phenol
- Hoeger, Sigurd
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p. 273 - 278
(2007/10/03)
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- Sulfene Mechanism in the Pyridine-catalysed Reactions of Alkanesulfonyl Halides with Phenols
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The influence of pyridine bases upon the rate and mechanism of the interaction of alkanesulfonyl halides with phenols in organic solvents has been studied.Two competing routes have been shown to be followed under the reaction conditions, i.e. elimination-
- Lyashchuk, Serge N.,Skrypnik, Yuri G.,Besrodnyi, Vladimir P.
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p. 1153 - 1160
(2007/10/02)
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