- Effect of the π-bridge on the light absorption and emission in push-pull coumarins and on their supramolecular organization
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A family of eight π-extended push–pull coumarins with cross-conjugated (amide) and directly conjugated (p-phenylene, alkyne, alkene) bridges were synthesized through a convergent strategy. Using an experimentally calibrated computational protocol, their UV–Visible light absorption and emission spectra in solution were investigated. Remarkably, amide-, alkyne- and alkene-bridges undergo comparable vertical excitations. The different nature of these bridges manifests during excited-state relaxation and fluorescence. We predict that these molecules can serve as building blocks for p-type semiconductors with low reorganization energies, below 0.2 eV. Since solid-state self-assembly is crucial for this application, we examined the effect of the π-bridge over the supramolecular organization in this family of compounds to determine if stacking prevails in these π-extended coumarin derivatives. Amide and alkyne spacers allow coplanar conformations which crystallize readily; p-phenylene hinders planarity yet allows facile crystallization; alkene-bridged molecules eluded all crystallization attempts. All the crystals obtained feature dense face-to-face π-stacking with 3.5–3.7 ? interlayer distances, expected to facilitate charge transfer processes in the solid state.
- Arcos-Ramos, Rafael,Carreón-Castro, María del Pilar,Farfán, Norberto,González-Rodríguez, Edgar,Guzmán-Juárez, Brenda,Maldonado-Domínguez, Mauricio,Miranda-Olvera, Montserrat,Santillan, Rosa
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supporting information
(2021/11/08)
-
- Gold N-Heterocyclic Carbene Catalysts for the Hydrofluorination of Alkynes Using Hydrofluoric Acid: Reaction Scope, Mechanistic Studies and the Tracking of Elusive Intermediates
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An efficient and chemoselective methodology deploying gold-N-heterocyclic carbene (NHC) complexes as catalysts in the hydrofluorination of terminal alkynes using aqueous HF has been developed. Mechanistic studies shed light on an in situ generated catalyst, formed by the reaction of Br?nsted basic gold pre-catalysts with HF in water, which exhibits the highest reactivity and chemoselectivity. The catalytic system has a wide alkyl substituted-substrate scope, and stoichiometric as well as catalytic reactions with tailor-designed gold pre-catalysts enable the identification of various gold species involved along the catalytic cycle. Computational studies aid in understanding the chemoselectivity observed through examination of key mechanistic steps for phosphine- and NHC-coordinated gold species bearing the triflate counterion and the elusive key complex bearing a bifluoride counterion.
- Bédard, Sandrine,Cavallo, Luigi,Falivene, Laura,Gauthier, Rapha?l,Nolan, Steven P.,Paquin, Jean-Fran?ois,Saab, Marina,Tzouras, Nikolaos V.,Van Hecke, Kristof,Zhang, Ziyun
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- Rip It off: Nitro to Nitroso Reduction by Iron Half-Sandwich Complexes
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Activation of [FeCl(dppe)Cp] (1) by chloride abstraction with Na[BArX4] (X = F, [B(3,5-(CF3)2-C6H3)4]; X = Cl, [B(3,5-Cl2-C6H3)4]) permits reactions with a range of nitro aromatics, RC6H4NO2 (R = halogen, Me, OMe, NO2 or NMe2), to give the cationic iron nitroso complexes [Fe{N(O)-C6H4R}(dppe)Cp][BArX4]) ([3][BArX4]). Similar reactions of 1 and Na[BArX4] with [Fe(NCC6H4NO2)(dppe)Cp][BArX4] gave bimetallic [{Fe(dppe)Cp}2{μ-NCC6H4N(O)}][BArF4]2. However, reactions of 1 and Na[BArX4] with 4-nitrophenol gave the first example of the bench-stable iron half-sandwich phenolate complex [Fe(OC6H4NO2)(dppe)Cp]+ rather than NO2 activation. The formation of complexes [3]+ likely proceeds via the unusual blue bimetallic species [{Fe(dppe)Cp}2{μ,κ2O,O′-O2NAr}]2+. This compound undergoes N-O bond cleavage, resulting in [3]+ and a FeIV=O species, which reacts via an internal C-H activation of the dppe ligand to give [FeIII(κ3O,P,P′-P(2-O-C6H4)(Ph)-C2H4-PPh2)Cp]+. Complexes [3]+ are stable under ambient conditions, are readily purified by column chromatography and can be isolated in up to 50% yield, considering that 0.5 equiv of 1 is required as the oxygen acceptor.
- Korb, Marcus,Hosseini Ghazvini, Seyed Mohammad Bagher,Moggach, Stephen A.,Meunier, Jean-Fran?ois,Bousseksou, Azzedine,Low, Paul J.
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p. 4986 - 4995
(2021/04/06)
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- The polyhedral nature of selenium-catalysed reactions: Se(iv) species instead of Se(vi) species make the difference in the on water selenium-mediated oxidation of arylamines
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Selenium-catalysed oxidations are highly sought after in organic synthesis and biology. Herein, we report our studies on the on water selenium mediated oxidation of anilines. In the presence of diphenyl diselenide or benzeneseleninic acid, anilines react with hydrogen peroxide, providing direct and selective access to nitroarenes. On the other hand, the use of selenium dioxide or sodium selenite leads to azoxyarenes. Careful mechanistic analysis and 77Se NMR studies revealed that only Se(iv) species, such as benzeneperoxyseleninic acid, are the active oxidants involved in the catalytic cycle operating in water and leading to nitroarenes. While other selenium-catalysed oxidations occurring in organic solvents have been recently demonstrated to proceed through Se(vi) key intermediates, the on water oxidation of anilines to nitroarenes does not. These findings shed new light on the multifaceted nature of organoselenium-catalysed transformations and open new directions to exploit selenium-based catalysis.
- Capperucci, Antonella,Dalia, Camilla,Tanini, Damiano
-
supporting information
p. 5680 - 5686
(2021/08/16)
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- Preparation method of acetenyl aniline
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The invention discloses a preparation method of acetenyl aniline, wherein the preparation method comprises the following steps: by using nitroethylbenzene as a raw material and MBr-MBrO3-H2SO4 (M=Na or K) as a bromination reagent, carrying out free radical bromination reaction to prepare 1,1-dibromo-1-(nitrophenyl)ethane, carrying out elimination reaction under the action of alkali to obtain nitrophenylacetylene, and finally, carrying out Fe/HCl reduction to obtain acetenyl aniline. The preparation method provided by the invention has the advantages of cheap and easily available raw materials, simple and safe operation, good reaction selectivity, high product yield, less emission of three wastes and the like.
- -
-
Paragraph 0079; 0081
(2021/04/14)
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- Fe-Catalyzed Selective Cyclopropanation of Enynes under Photochemical or Thermal Conditions
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The nucleophilic Fe-complex Bu4N[Fe(CO)3(NO)] (TBA[Fe]) catalyzes the cyclopropanation of enynes to substituted propargyl cyclopropanes using diazoesters as carbene surrogates. The catalyst can be activated either thermally in the presence of catalytic amounts of 4-nitroanisole or under photochemical conditions. Cyclopropanation occurs selectively at the enyne moiety; alternative olefinic moieties remain intact.
- Picher, Marie-Idrissa,Plietker, Bernd
-
supporting information
p. 340 - 344
(2020/01/11)
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- READ-THROUGH INDUCER AND PHARMACEUTICAL USE THEREOF
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PROBLEM TO BE SOLVED: To provide a novel read-through inducer. SOLUTION: The present invention relates to a compound represented by the general formula (I) [each symbol in the formula is as described in the specification] or a pharmaceutically acceptable
- -
-
Paragraph 0520-0524
(2020/08/04)
-
- Design, synthesis, antileishmanial, and antifungal biological evaluation of novel 3,5-disubstituted isoxazole compounds based on 5-nitrofuran scaffolds
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Nineteen 3,5-disubstituted-isoxazole analogs were synthesized based on nitrofuran scaffolds, by a [3 + 2] cycloaddition reaction between terminal acetylenes and 5-nitrofuran chloro-oxime. The compounds were obtained in moderate to very good yields (45–91%). The antileishmanial activity was assayed against the promastigote and amastigote forms of Leishmania (Leishmania) amazonensis. Alkylchlorinated compounds 14p–r were active on both the promastigote and amastigote forms, with emphasis on compound 14p, which showed strong activity against the amastigote form (IC50 = 0.6 μM and selectivity index [SI] = 5.2). In the alkyl series, compound 14o stands out with an IC50 = 8.5 μM and SI = 8.0 on the amastigote form. In the aromatic series, the most active compounds were those containing electron-donor groups, such as trimethoxy isoxazole 14g (IC50 = 1.2 μM and SI = 20.2); compound 14h, with IC50 = 7.0 μM and SI = 6.1; and compound 14j containing the 4-SCH3 group, with IC50 = 5.7 μM and SI = 10.2. In addition, the antifungal activity of 19 nitrofuran isoxazoles was evaluated against five strains of Candida (C. albicans, C. parapsilosis, C. krusei, C. tropicalis, and C. glabrata). Eleven isoxazole derivatives were active against C. parapsilosis, and compound 14o was found to be the most active (minimal inhibitory concentration [MIC] = 3.4 μM) for this strain. Compound 14p was active against all the strains tested, with an MIC = 17.5 μM for C. glabrata, lower than that of the fluconazole used as the reference drug.
- Trefzger, Ozildéia S.,Barbosa, Natália V.,Scapolatempo, Renata L.,das Neves, Amarith R.,Ortale, Maria L. F. S.,Carvalho, Diego B.,Honorato, Ant?nio M.,Fragoso, Mariana R.,Shuiguemoto, Cristiane Y. K.,Perdomo, Renata T.,Matos, Maria F. C.,Chang, Marilene R.,Arruda, Carla C. P.,Baroni, Adriano C. M.
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- Photochemical generation of the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical from caged nitroxides by near-infrared two-photon irradiation and its cytocidal effect on lung cancer cells
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Novel caged nitroxides (nitroxide donors) with near-infrared two-photon (TP) responsive character, 2,2,6,6-tetramethyl-1-(1-(2-(4-nitrophenyl)benzofuran-6-yl)ethoxy)piperidine (2a) and its regioisomer 2b, were designed and synthesized. The one-photon (OP) (365 ± 10 nm) and TP (710–760 nm) triggered release (i.e., uncaging) of the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical under air atmosphere were discovered. The quantum yields for the release of the TEMPO radical were 2.5% (2a) and 0.8% (2b) in benzene at ≈1% conversion of 2, and 13.1% (2a) and 12.8% (2b) in DMSO at ≈1% conversion of 2. The TP uncaging efficiencies were determined to be 1.1 GM at 740 nm for 2a and 0.22 GM at 730 nm for 2b in benzene. The cytocidal effect of compound 2a on lung cancer cells under photolysis conditions was also assessed to test the efficacy as anticancer agents. In a medium containing 100 μg mL?1 of 2a exposed to light, the number of living cells decreased significantly compared to the unexposed counterparts (65.8% vs 85.5%).
- Yamada, Ayato,Abe, Manabu,Nishimura, Yoshinobu,Ishizaka, Shoji,Namba, Masashi,Nakashima, Taku,Shimoji, Kiyofumi,Hattori, Noboru
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p. 863 - 873
(2019/04/17)
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- Rational Design, synthesis and biological evaluation of novel triazole derivatives as potent and selective PRMT5 inhibitors with antitumor activity
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Protein arginine methyltransferase 5 (PRMT5) is responsible for the mono-methylation and symmetric dimethylation of arginine, and its expression level and methyl transferring activity have been demonstrated to have a close relationship with tumorigenesis, development and poor clinical outcomes of human cancers. Two PRMT5 small molecule inhibitors (GSK3326595 and JNJ-64619178) have been put forward into clinical trials. Here, we describe the design, synthesis and biological evaluation of a series of novel, potent and selective PRMT5 inhibitors with antiproliferative activity against Z-138 mantle cell lymphoma cell line. Among them, compound C_4 exhibited the highest potency with enzymatic and cellular level IC50 values of 0.72 and 2.6 μM, respectively, and displayed more than 270-fold selectivity toward PRMT5 over several other isoenzymes (PRMT1, PRMT4 and PRMT6). Besides, C_4 demonstrated obvious cell apoptotic effect while reduced the cellular symmetric arginine dimethylation levels of SmD3 protein. The potency, small size, and synthetic accessibility of this compound class provide promising hit scaffold for medicinal chemists to further explore this series of PRMT5 inhibitors.
- Zhu, Kongkai,Shao, Jingwei,Tao, Hongrui,Yan, Xue,Luo, Cheng,Zhang, Hua,Duan, Wenhu
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p. 775 - 785
(2019/07/22)
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- Design, synthesis and biological evaluation of novel uracil derivatives bearing 1, 2, 3-triazole moiety as thymidylate synthase (TS) inhibitors and as potential antitumor drugs
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Research on thymidylate synthase inhibitors has been a hot spot for anticancer drug development. Here, based on the structures and pharmacological properties of two types of TS inhibitors, through a molecular assembly principle of drugs design, we designed and synthesized a series of 30 novel uracil derivatives as TS inhibitors. The antiproliferative ability of these compounds was evaluated against four cancer cell lines (A549, OVCAR-3, SGC-7901, and HepG2) by the MTT assay. Most of them showed excellent activities against all the tested cell lines. Furthermore, hTS assay results showed that these compounds have the unique ability to inhibit hTS activity in vitro. Notably, compound 13j exhibited the most potent activity against A549 cells (IC50 = 1.18 μM) and extremely prominent enzyme inhibition (IC50 = 0.13 μM), which was superior to the pemetrexed (PTX, IC50 = 3.29 μM and IC50 = 2.04 μM). Flow cytometric analysis showed the compound 13j could inhibit A549 cells proliferation by arresting the cell cycle in the G1/S phase, then induced the cell apoptosis. Further western blot analysis showed that compound 13j could down-regulate the cycle checkpoint proteins cyclin D1 and cyclin E to inhibit the cell cycle progression, and then induce intrinsic apoptosis by activating caspase-3, and reducing the ratio of bcl-2/bax. All of these results demonstrated that this new structure has potential drug-making properties and provides new ideas for drug development.
- Lu, Guo-qing,Li, Xin-yang,Mohamed O, Kamara,Wang, Depu,Meng, Fan-hao
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p. 282 - 296
(2019/03/27)
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- Triazole compound and application thereof
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The present invention provides a triazole compound having a structure represented by a formula (A), or a pharmaceutically acceptable salt, a stereoisomer, a prodrug molecule, a metabolite, or a solvate thereof. The compound can effectively inhibit kinase, especially FLT3 kinase, so as to regulate activation of a plurality of downstream pathways. The compound can be used for preparing medicines forpreventing and treating various diseases related to FLT3 kinase, such as leukemia, tumors, psoriasis, benign prostatic hyperplasia and metabolic diseases, etc.
- -
-
Paragraph 0092; 0095; 0098-0099
(2019/11/21)
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- Oxidative amidation of benzyl alcohol, benzaldhyde, benzoic acid styrene and phenyl acetylene catalyzed by ordered mesoporous HKUST-1-Cu: Effect of surface area on oxidative amidation reaction
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HKUST-1-Cu synthesized in the presence and absence of P-123 trough solvotermal method. After characterization using some different microscopic and spectroscopic techniques such as XRD, FT-IR, SEM, ICP, BET and TEM its catalytic activity was investigated in the oxidative coupling of benzyl alcohol, benzaldhyde, benzoic acid, styrene and phenyl acetylene with N,N-dialkylformamides for the preparation of N,N-dimethylformamides. Different derivatives of tertiary amides were synthesized in moderate to good yields in the presence of just ~0.28?mol% of this catalytic system. Reusability of the synthesized catalysts was examined and catalysts were reusable for 8 times without significant decrease in optimized conditions.
- Mohebali, Haleh,Mahjoub, Ali Reza,Karimi, Meghdad,Heydari, Akbar
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- DBU-Mediated Synthesis of Aryl Acetylenes or 1-Bromoethynylarenes from Aldehydes
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Two well known synthetic organic reactions Ramirez olefination and Corey-fuchs reactions are integrated in one-pot sequential manner for the synthesis of arylacetylenes and 1,3-enynes starting directly from commercially available aldehydes. The bicyclic amidine 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) along with additive NaOH not only exclusively afforded the terminal alkynes directly from the aldehydes, but also enhanced the reaction rate. The dynamic nature of DBU also facilitated the isolation of 1-bromoalkynes intermediate products. Selection of additive from NaOH and H2O served as a switch for the synthesis of terminal alkyne and 1-bromoalkynes, respectively. (Figure presented.).
- Thummala, Yadagiri,Karunakar, Galla V.,Doddi, Venkata Ramana
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supporting information
p. 611 - 616
(2019/01/04)
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- An Additive-Free, Base-Catalyzed Protodesilylation of Organosilanes
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We report an additive-free, base-catalyzed C-, N-, O-, and S-Si bond cleavage of various organosilanes in mild conditions. The novel catalyst system exhibits high efficiency and good functional group compatibility, providing the corresponding products in good to excellent yields with low catalyst loadings. Overall, this transition-metal-free process may offer a convenient and general alternative to current employing excess bases, strong acids, or metal-catalyzed systems for the protodesilylation of organosilanes.
- Yao, Wubing,Li, Rongrong,Jiang, Huajiang,Han, Deman
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p. 2250 - 2255
(2018/02/23)
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- Preparation and Reactions of Mono- and Bis-Pivaloyloxyzinc Acetylides
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Mono-pivaloyloxyzinc acetylide and bis-pivaloyloxyzinc acetylide were selectively prepared from ethynylmagnesium bromide in quantitative yields. These zinc reagents readily underwent Negishi cross-couplings with (hetero)aryl iodides or bromides as well as subsequent Sonogashira cross-couplings. 1,3-Dipolar cycloadditions of these zinc acetylides with benzylic azides produced zincated and bis-zincated triazoles which were trapped with several electrophiles. An opposite regioselectivity compared to the Cu-catalyzed click-reactions was observed.
- Tüllmann, Carl Phillip,Chen, Yi-Hung,Schuster, Robin J.,Knochel, Paul
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supporting information
p. 4601 - 4605
(2018/08/09)
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- Gold(i)-catalyzed cross-coupling reactions of aryldiazonium salts with organostannanes
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Gold(i)-catalyzed cross-coupling reactions of aryldiazonium salts with organostannanes are described. This redox neutral strategy offers an efficient approach to diverse biaryls, vinyl arenes and arylacetylenes. Monitoring the reaction with NMR and ESI-MS provided strong evidence for the in situ formation of Ph3PAuIR (R = aryl, vinyl and alkynyl) species which is crucial for the activation of aryldiazonium salts.
- Akram, Manjur O.,Shinde, Popat S.,Chintawar, Chetan C.,Patil, Nitin T.
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supporting information
p. 2865 - 2869
(2018/05/03)
-
- In Vitro, In Silico, and In Vivo Analyses of Novel Aromatic Amidines against Trypanosoma cruzi
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Five bis-arylimidamides were assayed as anti-Trypanosoma cruzi agents by in vitro, in silico, and in vivo approaches. None were considered to be pan-assay interference compounds. They had a favorable pharmacokinetic landscape and were active against trypomastigotes and intracellular forms, and in combination with benznidazole, they gave no interaction. The most selective agent (28SMB032) tested in vivo led to a 40% reduction in parasitemia (0.1 mg/kg of body weight/5 days intraperitoneally) but without mortality protection. In silico target fishing suggested DNA as the main target, but ultrastructural data did not match.
- Santos, Camila C.,Lionel, Jéssica R.,Peres, Raiza B.,Batista, Marcos M.,Da Silva, Patrícia B.,De Oliveira, Gabriel M.,Da Silva, Cristiane F.,Batista, Denise G. J.,Souza, Sandra Maria O.,Andrade, Carolina H.,Neves, Bruno J.,Braga, Rodolpho C.,Patrick, Donald A.,Bakunova, Svetlana M.,Tidwell, Richard R.,Soeiro, Maria de Nazaré C.
-
supporting information
(2018/02/06)
-
- Substituent Effects That Control Conjugated Oligomer Conformation through Non-covalent Interactions
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Although understanding the conformations and arrangements of conjugated materials as solids is key to their prospective applications, predictive power over these structural factors remains elusive. In this work, substituent effects tune non-covalent interactions between side-chain fluorinated benzyl esters and main-chain terminal arenes, in turn controlling the conformations and interchromophore aggregation of three-ring phenylene-ethynylenes (PEs). Cofacial fluoroarene-arene (ArF-ArH) interactions cause twisting in the PE backbone, interrupting intramolecular conjugation as well as blocking chromophore aggregation, both of which prevent the typically observed bathochromic shift observed upon transitioning PEs from solution to solid. This work highlights two structural factors that determine whether the ArF-ArH interactions, and the resulting twisted, unaggregated chromophores, occur in these solids: (i) the electron-releasing characteristic of substituents on ArH, with more electron-releasing character favoring ArF-ArH interactions, and (ii) the fluorination pattern of the ArF ring, with 2,3,4,5,6-pentafluorophenyl favoring ArF-ArH interactions over 2,4,6-trifluorophenyl. These trends indicate that considerations of electrostatic complementarity, whether through a polar-π or substituent-substituent mechanism, can serve as an effective design principle in controlling the interaction strengths, and therefore the optoelectronic properties, of these molecules as solids.
- Sharber, Seth A.,Baral, Rom Nath,Frausto, Fanny,Haas, Terry E.,Müller, Peter,Thomas, Samuel W.
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supporting information
p. 5164 - 5174
(2017/05/04)
-
- Nucleophilic and electrophilic cyclization of N-alkyne-substituted pyrrole derivatives: Synthesis of pyrrolopyrazinone, pyrrolotriazinone, and pyrrolooxazinone moieties
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Intramolecular nucleophilic and electrophilic cyclization of N-alkyne-substituted pyrrole esters is described. Efficient routes towards the synthesis of pyrrolopyrazinone, pyrrolotriazinone and pyrrolooxazinone have been developed. First, N-alkyne-substituted pyrrole ester derivatives were synthesized. Introduction of various substituents into the alkyne functionality was accomplished by a copper-catalyzed cross-coupling reaction. Nucleophilic cyclization of N-alkyne-substituted methyl 1H-pyrrole-2-carboxylates with hydrazine afforded the 6-exo-dig/6-endo-dig cyclization products depending on the electronic nature of the substituents attached to the alkyne. On the other hand, cyclization of N-alkyne-substituted methyl 1H-pyrrole-2-carboxylates with iodine only resulted in the formation of the 6-endo-dig cyclization product regardless of the substitution of the alkyne functionality.
- Yenice, I??l,Basceken, Sinan,Balci, Metin
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p. 825 - 834
(2017/06/20)
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- Controlled Reactivity of 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) in the Selective Synthesis of 1-(Bromoethynyl)arenes
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The nucleophilic reactivity of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) was completely controlled by the formation of monohydrate (DBU?H2O) in the synthesis of 1-(bromoethynyl)arenes from 1,1-dibromoalkenes. Differential reactivity of DBU in pr
- Krishna Moodapelly, Shiva,Sharma, Gangavaram V. M.,Ramana Doddi, Venkata
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p. 1535 - 1540
(2017/05/05)
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- Na2S-mediated synthesis of terminal alkynes from: Gem -dibromoalkenes
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The Na2S-mediated facile synthesis of terminal alkynes from gem-dibromoalkenes, at 20/40 °C under open flask conditions has been developed. Various precursors derived from heteroaromatic/aromatic/aliphatic aldehydes were found compatible. The reaction is proposed to proceed through the Fritsch-Buttenberg-Wiechell (FBW) rearrangement involving the corresponding vinyl carbene. Using mild reaction conditions with inexpensive Na2S·9H2O under air atmosphere has significant advantages over earlier routes.
- Singh, Radhey M.,Nandini, Durgesh,Bharadwaj, Kishor Chandra,Gupta, Tanu,Singh, Raj Pal
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supporting information
p. 9979 - 9982
(2017/12/26)
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- New cyclometalated iridium(III) dye chromophore complexes for n-type dye-sensitised solar cells
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The synthesis of seven iridium complexes where aryl-1,2,3-triazole (Ar-tz) moieties act as cyclometalating ligands with 2,2′-bipyridyl-4,4′-dicarboxylic acid (dcb) as a N^N ancillary/anchoring ligand, is described. The new dye complexes [Ir(Ar-tz)2(dcb)][PF6] (AS1-7) were prepared in a two stage procedure with iridium-chloride dimer isolation. DFT analysis together with photophysical investigations reveal how using different substituents on the phenyl ring, or a different aryl system, lead to the tuning of the absorption and emission properties of these complexes. Computational studies therefore demonstrate an ideal HOMO-LUMO directionality for the [Ir(Ar-tz)2(dcb)]+framework, promoting a favourable electron transfer into the TiO2conduction band upon photoexcitation. Preliminary unoptimized tests on TiO2DSSCs have been carried out which show similar photovoltaic performance to the [Ir(ppy)2(dcb)][PF6] (ppy = 2-phenylpyridine) benchmark.
- Sinopoli, Alessandro,Wood, Christopher J.,Gibson, Elizabeth A.,Elliott, Paul I.P.
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supporting information
p. 81 - 89
(2016/12/26)
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- A copper (II) (II) composite chlorinating agent and copper-based composite chlorinating agent synthesis of 1-chloro-2-aryl acetylene method
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The invention discloses a copper (II) composite chlorinating agent and a method for synthesizing 1-chlorine-2-aryl acetylene based on the copper (II) composite chlorinating agent. The structural formula of the copper (II) composite chlorinating agent is CuCl2.xNaCl.yAl2O3. The chlorinating agent is applicable to chlorination of various substituted aryl acetylene substrates, and is high in universality; the chlorinating agent can directly carry out chlorination reaction on aryl acetylene so as to obtain a 1-chlorine-2-aryl acetylene product; the method is mild in reaction condition, 1-chlorine-2-aryl acetylene can be synthesized with high yield and high selectivity, and the production cost of the 1-chlorine-2-aryl acetylene derivative is greatly lowered.
- -
-
Paragraph 0021-0023
(2016/11/24)
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- Acetylenic Scaffolding with Subphthalocyanines
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A new boron subphthalocyanine (SubPc) derivative with a terminal alkyne substituent on the central boron atom was prepared by substitution of a triflate at the boron atom with but-3-yn-1-ol. This compound was shown to be a versatile building block for metal-catalyzed coupling reactions, such as modified Glaser-Hay, Cadiot-Chodkiewicz, and Sonogashira reactions as well as the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC). For example, metal-catalyzed reactions provided access to a SubPc dimer containing a butadiyne bridging unit, two different SubPc-fullerene dyads as well as two cross-conjugated SubPc-tetraethynylethene (TEE) scaffolds. These TEEs containing two silyl-protected alkyne units are potential building blocks for further acetylenic scaffolding. The work shows how the axial position is post-functionalized in steps not involving a substitution reaction at the central boron atom, which is otherwise often used as the terminal step in axial functionalization of SubPcs.
- Gotfredsen, Henrik,Jevric, Martyn,Kadziola, Anders,Nielsen, Mogens Brondsted
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supporting information
p. 17 - 21
(2016/01/20)
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- Cleavage of the Carbon–Carbon Triple Bonds of Arylacetylenes for the Synthesis of Arylnitriles without a Metal Catalyst
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Cleavage of the carbon–carbon triple bonds of alkynes was achieved, which led to the synthesis of arylnitriles under transition-metal-free conditions. A vast range of terminal alkyne substrates underwent this reaction to provide the corresponding nitriles in moderate to good yields with good functional group tolerance.
- Lin, Yuanguang,Song, Qiuling
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supporting information
p. 3056 - 3059
(2016/07/12)
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- Synthesis and cytotoxicity evaluation of aryl triazolic derivatives and their hydroxymethine homologues against B16 melanoma cell line
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In this manuscript we describe synthesis and cytotoxicity evaluation of some triazolic derivatives against B16 melanoma cell line. For this purpose, we transformed a set of aromatic aldehydes into terminal alkynes, using Besthmann-Ohira reagent, and we made the corresponding hydroxymethyl homologated alkynes by an acetylene Grignard reagent. These generated two sets of alkynes were then subjected to a copper(I)-catalyzed alkyne-azide cycloaddition reaction (CuAAC) using a solid-supported catalyst (Amberlyst A-21?CuI), with a third set composed of organic azides. Synthesized triazoles were then tested in?vitro against B16 melanoma cell line. Amongst them, compounds a1b1 (R1?=?p-nitrophenyl, R2?=?benzyl), a4b1 (R1?=?naphthyl, R2?=?benzyl) and a4b5 (R1?=?naphthyl, R2?=?(R/S)- dioxolane) showed the best activity against B16 melanoma cells, with IC50of 5.12, 3.89 and 6.60?μM respectively.
- Kalhor-Monfared, Shiva,Beauvineau, Claire,Scherman, Daniel,Girard, Christian
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supporting information
p. 436 - 441
(2016/07/15)
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- Synthesis and biological evaluation of a novel betulinic acid derivative as an inducer of apoptosis in human colon carcinoma cells (HT-29)
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Abstract A novel family of betulinic acid analogues, carrying a triazole unit at C-3 attached through a linker, was synthesized by the application of azide-alkyne "Click reaction". These were screened for their anticancer activity against different cancer cells and normal human PBMC by MTT assay. Compound 2c [(3S)-3-{2-(4-(hydroxymethyl-1H-1,2,3-triazol-1-yl)acetyloxy}-lup-20(29)-en-28-oic acid] was found as the most potent inhibitor of cell line HT-29 with IC50 value 14.9 μM. Its role as an inducer of apoptosis was investigated in this cell line by Annexin-V/PI binding assay and by following its capability for ROS generation, depolarization of mitochondrial transmembrane potential, activation of caspases, PARP cleavage, nuclear degradation and expression of pro- and anti-apoptotic proteins. It exhibited much higher cytotoxicity than the standard drug 5-fluorouracil but showed negligible cytotoxicity towards normal PBMC. Elevated level of ROS generation, activation of caspase 3 and caspase 9, DNA fragmentation, higher expression of Bax and Bad, lower expression of Bcl2 and Bcl-xl, and increased level of Bax/Bcl-xl ratio identified 2c as a promising inducer of apoptosis that follows a mitochondria dependent pathway. Bio-physical studies indicate that compound 2c acts as a minor groove binder to the DNA.
- Chakraborty, Biswajit,Dutta, Debasmita,Mukherjee, Sanjukta,Das, Supriya,Maiti, Nakul C.,Das, Padma,Chowdhury, Chinmay
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supporting information
p. 93 - 105
(2015/08/18)
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- Design, Synthesis, and Evaluation of Triazole Derivatives That Induce Nrf2 Dependent Gene Products and Inhibit the Keap1-Nrf2 Protein-Protein Interaction
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The transcription factor Nrf2 regulates the expression of a large network of cytoprotective and metabolic enzymes and proteins. Compounds that directly and reversibly inhibit the interaction between Nrf2 and its main negative regulator Keap1 are potential pharmacological agents for a range of disease types including neurodegenerative conditions and cancer. We describe the development of a series of 1,4-diphenyl-1,2,3-triazole compounds that inhibit the Nrf2-Keap1 protein-protein interaction (PPI) in vitro and in live cells and up-regulate the expression of Nrf2-dependent gene products.
- Bertrand, Hélène C.,Schaap, Marjolein,Baird, Liam,Georgakopoulos, Nikolaos D.,Fowkes, Adrian,Thiollier, Clarisse,Kachi, Hiroko,Dinkova-Kostova, Albena T.,Wells, Geoff
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supporting information
p. 7186 - 7194
(2015/10/05)
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- Tunable electron acceptors based on cyclopenta[hi]aceanthrylenes
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A series of substituted cyclopenta[hi]aceanthrylene derivatives with electron donating (NH2, OCH3), neutral (H), and electron withdrawing (COOH, CF3, CN, NO2) substituents were prepared. A room-temperature Sonogashira cross-coupling reaction between 2,7-dibromocyclopenta[hi]aceanthrylene and an appropriately functionalized phenylene ethynylene precursor was utilized to access the materials that were characterized by Nuclear Magnetic Resonance Spectroscopy (NMR), cyclic voltammetry (CV), and UV-Vis spectroscopy. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) were systematically varied when proceeding from electron donating to electron withdrawing substituents. The optical band gap was significantly altered for the most electron donating species, while little change was observed between different electron withdrawing substituents. This study demonstrates the ability to control the frontier orbital energies of this class of cyclopenta-fused polycyclic aromatic hydrocarbon materials through selective substitution.
- Zhu, Xinju,Yuan, Bingxin,Plunkett, Kyle N.
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supporting information
p. 7105 - 7107
(2015/12/01)
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- Topochemical polymerization of unsymmetrical aryldiacetylene supramolecules with nitrophenyl substituents utilizing C-H...π interactions
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Diacetylenes are versatile building blocks, in which many functional groups can be incorporated for the construction of new materials with desirable properties. In this study, 6-(p or m-nitrophenyl)-3,5-hexadiyne-1-ol (4a or 4b) containing nitrophenyl groups (host) and 2-hydroxyethyl groups (guest) in different diacetylene terminals were designed to establish an ordered supramolecular assembly that is complied with the strict requirements for the topochemical polymerization of diacetylenes. Crystal film and bulk crystals of compound 4b were obtained successfully by cast film and re-precipitation methods. Both of these could photopolymerize to the corresponding regular poly(diacetylene) polymer, as evidenced by UV-vis, IR, FL and Raman spectroscopy. The electrochemical properties and behaviors of 4a and 4b were also investigated, and the results show that the differences between the para and meta positions of the mono-phenylacetylene substituents probably result from the topochemical polymerization. Thus, m-nitrophenylbutadiyne derivatives with sizeable C-H...π interactions seemed to be effective for the formation of a polymerizable packing, which is appropriate for topochemical polymerization.
- Wang, Shichao,Li, Yong,Liu, Hui,Li, Jinpeng,Li, Tiesheng,Wu, Yangjie,Okada, Shuji,Nakanishi, Hachiro
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p. 5467 - 5474
(2015/05/20)
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- An efficient method for the production of terminal alkynes from 1,1-dibromo-1-alkenes and its application in the total synthesis of natural product dihydroxerulin
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An efficient method of preparing various terminal alkynes from 1,1-dibromo-1-alkenes by using TBAF (tetra-n-butylammonium fluoride) as a base and triphenylphosphane as a reductant was developed. This method is strong base and low/high temperatures free, and can tolerate a broad range of substrates. These advantages were well demonstrated by the application of this method to the total synthesis of polyene natural product dihydroxerulin.
- Liu, Shihui,Chen, Xiaobei,Hu, Yanwei,Yuan, Laiqi,Chen, Shaohua,Wu, Ping,Wang, Wei,Zhang, Shilei,Zhang, Wei
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p. 553 - 560
(2015/03/05)
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- The Dual Role of 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) in the Synthesis of Terminal Aryl- and Styryl-Acetylenes via Umpolung Reactivity
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The dual role of the bicyclic amidine base 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) was demonstrated in a synthesis of terminal aryl- and styryl-acetylenes. Mechanistically, a tandem process involving elimination/Umpolung/protonation occurs in a single step to generate terminal aryl- and styryl-acetylenes from geminal dibromoalkenes. The key to the success of this transformation lies in the organobase-mediated generation of the acetylide from the 1-bromoalkynes at room temperature. The unique characteristics of DBU as an inherently safer reagent make it an attractive alternative to previous systems wherein required pyrophoric reagents and nonambient temperatures remain unsolved issues. The procedure does not work for the synthesis of alkyl-acetylenes.
- Morri, Ashok Kumar,Thummala, Yadagiri,Doddi, Venkata Ramana
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supporting information
p. 4640 - 4643
(2015/09/28)
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- Visible light-mediated gold-catalysed carbon(sp2)-carbon(sp) cross-coupling
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A dual photoredox and gold-catalysed cross-coupling reaction of alkynyltrimethylsilanes and aryldiazonium tetrafluoroborates is described. The reaction proceeds through visible-light mediated oxidative addition of aryldiazoniums, transmetalation of alkynyltrimethylsilanes and aryl-alkynyl reductive elimination. Exclusive selectivity for silyl-substituted alkynes is observed, with no reactivity observed for terminal alkynes.
- Kim, Suhong,Rojas-Martin, Jaime,Toste, F. Dean
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- Falling-solid flash vacuum pyrolysis: An efficient preparation of arylacetylenes
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Automated falling-solid flash vacuum pyrolysis allows the rapid and efficient synthesis of a variety of arylacetylenes from 4-arylmethylidene-5(4H)-isoxazolone derivatives, which were prepared from aldehyde precursors. The acetylenes are readily obtained in multigram quantities. Taking the heat: Unlike in flash vacuum pyrolysis, involatile compounds can be used in falling-solid flash vacuum pyrolysis (FS-FVP). This method is employed for the rapid and efficient synthesis of a variety of arylacetylenes from 4-arylmethylidene-5(4H)-isoxazolones, which were in turn prepared from aldehyde precursors.
- Wentrup, Curt,Becker, Jürgen,Winter, Hans-Wilhelm
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supporting information
p. 5702 - 5704
(2015/09/21)
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- Tandem Claisen Rearrangement/6-endo Cyclization Approach to Allylated and Prenylated Chromones
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Allyl, dimethylallyl and prenyl ethers derived from o-acylphenols reacted upon microwave irradiation to form C-allylated or -prenylated chromone derivatives, depending on the substitution pattern of the arene and the allyl substituent. The reaction proceeds through a tandem Claisen rearrangement and 6-endo-trig or 6-endo-dig cyclization sequence. For prenyl ethers, the tandem sequence can be extended by a Cope rearrangement to furnish 6-prenylchromones. The method is potentially useful for the synthesis of natural products and drugs.
- Schmidt, Bernd,Riemer, Martin,Schilde, Uwe
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supporting information
p. 7602 - 7611
(2016/01/25)
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- Autotandem catalysis: Synthesis of pyrroles by gold-catalyzed cascade reaction
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A novel synthesis of substituted pyrroles by a gold(I)-catalyzed cascade reaction has been developed. The reaction proceeded with an autotandem catalysis consisting of an initial addition of gold-acetylide to an acetal moiety and was followed by gold-catalyzed 5-endo-dig cyclization and aromatization. Gold catalysts play a dual role in activating nucleophilicity or electrophilicity of terminal acetylenes by forming gold-acetylides or by π-coordination. The formal (3 + 2) annulation of two components provided a variety of substituted pyrroles in a modular fashion.
- Ueda, Hirofumi,Yamaguchi, Minami,Kameya, Hiroshi,Sugimoto, Kenji,Tokuyama, Hidetoshi
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supporting information
p. 4948 - 4951
(2015/04/27)
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- Regio- and stereoselective dimerization of arylacetylenes and optical and electrochemical studies of (E)-1,3-enynes
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The N-heterocyclic carbene palladium complex (SIPr)Pd(cinnamyl)Cl [SIPr=N,N'-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene) promotes regio- and stereospecific dimerization of a variety of arylalkynes to give (E)-1,3-enynes in good to excellent yields. An efficient and practical procedure for their synthesis was developed using a biphasic aqueous alkali/heptane system. Optical and electronic properties of (E)-1,3-enynes are highly tunable. Depending on the nature of the substituents, HOMO energies vary in the range 5.3-6.0eV. (E)-1,3-Enynes can exhibit intense photoluminescence in the spectral region 350-500nm.
- Morozov, Oleg S.,Asachenko, Andrey F.,Antonov, Denis V.,Kochurov, Vitaly S.,Paraschuk, Dmitry Yu.,Nechaev, Mikhail S.
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supporting information
p. 2671 - 2678
(2014/09/29)
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- Synthesis of 1,2,3-triazoles from azide-derivatised aminocyclitols by catalytic diazo transfer and CuAAC click chemistry
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CuII-catalysed diazo transfer and CuI-catalysed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) "click chemistry" were used to synthesis C7N aminocyclitol-derivatised 1,2,3-triazoles. In the course of this work, the -N=N- moiety was transferred onto C7N aminocyclitols such as validamine, valienamine and valiolamine by employing imidazole-1-sulfonyl azide as the diazo transfer reagent with catalysis by CuII, ZnII and NiII, in moderate to good yields. The obtained azidocyclitols were coupled with various terminal alkynes under modified Meldal's conditions with good to excellent yields. The stereo- and regiochemistry of the products were confirmed by 2D-NMR (NOESY and HMBC). One-pot syntheses of the corresponding 1,2,3-triazoles, as safer and more efficient procedures, were also investigated and gave moderate to good yields. Copyright
- Ji, Li,Zhou, Guo-Quan,Qian, Chao,Chen, Xin-Zhi
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supporting information
p. 3622 - 3636
(2014/06/23)
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- "quick and click" assembly of functionalised indole rings via metal-promoted cyclative tandem reactions
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An efficient and convenient synthesis of a variety of decorated indoles using a three-component tandem metal-catalysed process is described. We propose here a new "synthetic kit" that allows for the "quick and click" assembly of indole rings using readily available, and inexpensive starting materials under environmentally friendly reaction conditions. This journal is
- Capitta, Francesca,De Luca, Lidia,Porcheddu, Andrea
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p. 59297 - 59301
(2015/02/19)
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- Palladium nanoparticles catalyzed Sonogashira reactions for the one-pot synthesis of symmetrical and unsymmetrical diarylacetylenes
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A variety of symmetrical and unsymmetrical diarylacetylenes are synthesized by ligand-free palladium nanoparticles catalyzed copper-free and amine-free Sonogashira cross-coupling reactions between aryl iodides and trimethylsilylacetylene (TMSA) under mild reaction conditions.
- Mandali, Pavan Kumar,Chand, Dillip Kumar
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- Palladium-catalyzed trifluoroethylation of terminal alkynes with 1,1,1-trifluoro-2-iodoethane
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An efficient Csp-CH2CF3 bond-forming reaction via Pd-catalyzed 2,2,2-trifluoroethylation of aryl and alkyl terminal alkynes has been developed. This protocol proceeds under mild conditions using the readily available and cheap reagent CF3CH2I as the source of the CH2CF3 group. Various terminal aryl alkynes as well as alkylacetylenes can be transformed into the corresponding trifluoroethylated products in good-to-excellent yields. The method is tolerant of carbonyl, nitro, ester, cyano, and even formyl groups.
- Feng, Yi-Si,Xie, Chuan-Qi,Qiao, Wen-Long,Xu, Hua-Jian
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supporting information
p. 936 - 939
(2013/03/28)
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- CLASS II HMG-COA REDUCTASE INHIBITORS AND METHODS OF USE
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Disclosed are compositions and methods for treating bacterial infections.
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Paragraph 0049
(2014/01/08)
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- Mn-catalyzed aromatic C-H alkenylation with terminal alkynes
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The first manganese-catalyzed aromatic C-H alkenylation with terminal alkynes is described. The procedure features an operationally simple catalyst system containing commercially available MnBr(CO)5 and dicyclohexylamine (Cy2NH). The reaction occurs readily in a highly chemo-, regio-, and stereoselective manner delivering anti-Markovnikov E-configured olefins in high yields. Experimental study and DFT calculations reveal that (1) the reaction is initiated by a C-H activation step via the cooperation of manganese and base; (2) manganacycle and alkynylmanganese species are the key reaction intermediates; and (3) the ligand-to-ligand H-transfer and alkynyl-assisted C-H activation are the key steps rendering the reaction catalytic in manganese.
- Zhou, Bingwei,Chen, Hui,Wang, Congyang
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supporting information
p. 1264 - 1267
(2013/03/14)
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- Rhodium-catalyzed chemo- and regioselective cross-dimerization of two terminal alkynes
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Cross-dimerization of terminal arylacetylenes and terminal propargylic alcohols/amides has been achieved in the presence of a rhodium catalyst. This method features high chemo- and regioselectivities rendering convenient and atom economical access to functionalized enynes.
- Xu, Hua-Dong,Zhang, Ren-Wei,Li, Xiaoxun,Huang, Suyu,Tang, Weiping,Hu, Wen-Hao
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supporting information
p. 840 - 843
(2013/03/29)
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- Cationic dirhodium carboxylate-catalyzed synthesis of dihydropyrimidones from propargyl ureas
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Cationic Rh(II) complexes are able to catalyze the regioselective hydroamination of propargyl ureas in a 6-endo fashion. This transformation permits access to interesting substitution patterns of dihydropyrimidines, which have found use as nucleotide exch
- Yang, Miao,Odelberg, Shannon J.,Tong, Zongzhong,Li, Dean Y.,Looper, Ryan E.
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supporting information
p. 5744 - 5750
(2013/06/27)
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- Specific interaction modes in the crystal structures of oligofluorinated tolanes featuring additional electron donor and acceptor groups
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A series of partially fluorinated and specifically para-substituted tolanes (1-4) have been synthesized via palladium-catalyzed Sonogashira cross-coupling reaction. The single-crystal structures have been determined by X-ray diffraction. The molecules ado
- Stein, Mario,Berger, Ricarda,Seichter, Wilhelm,Hulliger, Jürg,Weber, Edwin
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scheme or table
p. 231 - 239
(2012/04/04)
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- Synthesis, characterization, and solid-state polymerization of cross-conjugated octatetraynes
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Two series of cross-conjugated 1,3,5,7-octatetraynes (1a-1l and 6a-6d) have been synthesized. UV-vis spectroscopic analysis shows that pendent groups connected to the cross-conjugated skeleton have little effect on the λmax energies, irrespective of whether the groups are electron withdrawing or donating. A number of the isolated products readily give crystals suitable for X-ray crystallography, and the solid-state structural properties of five derivatives (1k, 1l, 6a, 6c, and 6d) have been examined by X-ray crystallographic analysis. Parallel packing of the polyynes in the solid state indicates that four of the five samples are potentially suitable for topochemical polymerization, based on solid-state packing parameters θ, R, and d. Attempts to effect a solid-state reaction have been explored through UV-vis and γ-ray irradiation as well as thermal heating. The course of these reactions was monitored by differential scanning calorimetry (DSC) analysis, as well as UV-vis and solid-state 13C NMR spectroscopy (for 1d, 1j, 1k, and 6d), which offered evidence of polymer formation from these reactions. Structural determination of the product(s), however, remains elusive.
- Zhao, Yuming,Luu, Thanh,Bernard, Guy M.,Taerum, Tyler,McDonald, Robert,Wasylishen, Roderick E.,Tykwinski, Rik R.
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p. 994 - 1014
(2013/02/22)
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- One-pot, two-step conversion of aldehydes to phosphonyl- and sulfonylpyrazoles using Bestmann-Ohira reagent
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A one-pot, two-step, three-component method for the conversion of commercially available aldehydes to phosphonylpyrazoles has been developed, demonstrating, for the first time, the dual reactivity of the Bestmann-Ohira reagent (BOR) in a single-pot transformation. This method, extended to the synthesis of sulfonylpyrazoles by employing BOR in the first step and a diazomethyl sulfone in the second step, is complementary, with regard to regioselectivity, to the previous methods for the synthesis of such functionalized pyrazoles.
- Kumar, Rahul,Verma, Deepti,Mobin, Shaikh M.,Namboothiri, Irishi N. N.
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supporting information; experimental part
p. 4070 - 4073
(2012/09/21)
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- Convenient synthesis of terminal alkynes from anti-3-aryl-2,3- dibromopropanoic acids using a K2CO3/DMSO system
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A convenient, efficient, and generally applicable method was developed for the synthesis of terminal alkynes from anti-3-aryl-2,3-dibromopropanoic acids in the presence of DMSO and K2CO3.
- Cheng, Xuezhi,Jia, Jun,Kuang, Chunxiang
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p. 2350 - 2354
(2012/02/03)
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