- N-Heterocyclic Carbene (NHC)-Catalyzed One-Pot Aerobic Oxidative Synthesis of 2-Substituted Benzo[ d ]oxazoles, Benzo[ d ]thiazoles and 1,2-Disubstituted Benzo[ d ]imidazoles
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N-Heterocyclic carbene (NHC), generated in situ from easily available N-heterocyclic imidazolium salt with air as terminal oxidant, has successfully been utilized as a cheap and efficient catalyst for one-pot aerobic oxidative synthesis of 2-arylbenzo[ d ]oxazoles, 2-substituted benzo[ d ]thiazoles, and 1,2-disubstituted benzo[ d ]imidazoles.
- Zhou, Quan,Liu, Shu,Ma, Ming,Cui, He-Zhen,Hong, Xi,Huang, Shuang,Zhang, Jing-Fan,Hou, Xiu-Feng
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supporting information
p. 1315 - 1322
(2018/03/10)
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- Highly efficient AgNO3-catalyzed approach to 2-(benzo[d]azol-2-yl)phenols from salicylaldehydes with 2-aminothiophenol, 2-aminophenol and benzene-1,2-diamine
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A new, convenient and efficient AgNO3-catalyzed strategy for the preparation of 2-(benzo[d]azol-2-yl)phenol derivatives in good to excellent yields (63–98%) is described. The reaction proceeds via condensation/intramolecular nucleophilic addition/oxidation process between substituted salicylaldehydes and 2-aminothiophenol, 2-aminophenol or benzene-1,2-diamine under mild reaction conditions. Notably, this reaction utilizes cheap AgNO3 as a readily available and low-cost benign oxidant at low catalyst loadings with excellent functional group tolerance.
- He, Xinwei,Wu, Yuhao,Jin, Wenjing,Wang, Xiaoshun,Wu, Cong,Shang, Yongjia
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- Rhodium(III)-Catalyzed ortho-Heteroarylation of Phenols through Internal Oxidative C-H Activation: Rapid Screening of Single-Molecular White-Light-Emitting Materials
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Reported herein is the first example of a transition-metal-catalyzed internal oxidative C-H/C-H cross-coupling between two (hetero)arenes through a traceless oxidation directing strategy. Without the requirement of an external metal oxidant, a wide range of phenols, including phenol-containing natural products, can undergo the coupling with azoles to assemble a large library of highly functionalized 2-(2-hydroxyphenyl)azoles. The route provides an opportunity to rapidly screen white-light-emitting materials. As illustrative examples, two bis(triphenylamine)-bearing 2-(2-hydroxyphenyl)oxazoles, which are difficult to access otherwise, exhibit bright white-light emission, high quantum yield, and thermal stability. Also presented is the first example of the white-light emission, in a single excited-state intramolecular proton transfer system, of 2-(2-hydroxyphenyl)azoles, thus highlighting the charm of C-H activation in the discovery of new organic optoelectronic materials.
- Li, Bijin,Lan, Jingbo,Wu, Di,You, Jingsong
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p. 14008 - 14012
(2016/01/25)
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- Palladium catalyzed Csp2-H activation for direct aryl hydroxylation: The unprecedented role of 1,4-dioxane as a source of hydroxyl radicals
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A novel strategy for direct aryl hydroxylation via Pd-catalysed Csp2-H activation through an unprecedented hydroxyl radical transfer from 1,4-dioxane, used as a solvent, is reported with bio relevant and sterically hindered heterocycles and various acyclic functionalities as versatile directing groups.
- Seth, Kapileswar,Nautiyal, Manesh,Purohit, Priyank,Parikh, Naisargee,Chakraborti, Asit K.
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p. 191 - 194
(2015/01/09)
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- Application of nano SnO2 as a green and recyclable catalyst for the synthesis of 2-aryl or alkylbenzoxazole derivatives under ambient temperature
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Application of nano SnO2 as an efficient and benign catalyst has been explored for the synthesis of 2-aryl or alkylbenzoxazole derivatives via condensation reaction of aldehyde with 2-aminophenol. The reactions proceed under heterogeneous and mild conditions in ethanol at room temperature to provide 2-aryl or alkylbenzoxazoles in high yields.
- Vahdat, Seyed Mohammad,Raz, Shima Ghafouri,Baghery, Saeed
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p. 579 - 585
(2014/07/07)
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- Cuprous oxide on charcoal-catalyzed ligand-free synthesis of 1,4-disubstituted 1,2,3-triazoles via click chemistry
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Cuprous oxide on charcoal (Cu2O/C), the preparation of which is described for the first time, catalyzes the formation of 1,4-disubstituted 1,2,3-triazoles from organic azides and terminal alkynes in good to excellent yields (69-94%). These disu
- Lopez-Ruiz, Heraclio,De La Cerda-Pedro, Jose Emilio,Rojas-Lima, Susana,Perez-Perez, Imelda,Rodriguez-Sanchez, Brianda Viridiana,Santillan, Rosa,Coreno, Oscar
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p. 139 - 164
(2013/06/27)
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- Phenylboronic acid catalyzed-cyanide promoted, one-pot synthesis of 2-(2-hydroxyphenyl)benzoxazole derivatives
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A novel, one-pot, phenylboronic acid catalyzed, cyanide promoted synthesis of 2-(2-hydroxyphenyl)benzoxazoles from salicylaldehydes and o-aminophenols is described. The synthesis is characterized by mild conditions, short reaction times, and simple workup of crystalline, high purity products.
- Lopez-Ruiz, Heraclio,Briseno-Ortega, Horacio,Rojas-Lima, Susana,Santillan, Rosa,Farfan, Norberto
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supporting information; experimental part
p. 4308 - 4312
(2011/08/22)
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- An efficient potassium cyanide-promoted synthesis of 2-arylbenzoxazoles from [4.3.0]boron heterobicycles
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The 2-arylbenzoxazoles 3a-f were produced in moderate to excellent yields merely by stirring a potassium cyanide (3 equiv)-containing methanol solution of the borobicyclic compounds 1a-f at room temperature. These compounds were fully characterized spectroscopically [IR, 1H, and 13C NMR and X-ray analysis (3a)] and by elemental analysis. Crown Copyright
- López-Ruiz, Heraclio,Brise?o-Ortega, Horacio,Rojas-Lima, Susana,Santillán, Rosa,Farfán, Norberto
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experimental part
p. 2633 - 2635
(2010/06/16)
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- COMPOUNDS HAVING ELECTRON TRANSPORT PROPERTIES, THEIR PREPARATION AND USE
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The invention provides compounds having utility inter alia as electron transport materials in optical light emitting diodes (OLEDs) and of the formula (I), (Il) or (III). Embodiments of the compounds when incorporated as electron transport layers in OLEDs exhibit a greater current density for a given voltage than corresponding devices where the electron transport material is aluminium quinolate.
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Page/Page column 47
(2010/04/03)
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