7007-67-2Relevant articles and documents
IRIDIUM COMPLEX AND ORGANIC ELECTROLUMINESCENCE DEVICE USING THE SAME
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Paragraph 0020-0021, (2020/06/08)
The present invention discloses an iridium complex represented by the following formula (1) and an organic electroluminescence device using the iridium complex as a phosphorescent dopant material. The phosphorescent dopant material may lower a driving voltage and power consumption and increase a current efficiency and half-life of the organic electroluminescence device. The same definition as described in the present invention.
Selective [5 + 1] and [5 + 2] Cycloaddition of Ynamides or Propargyl Esters with Benzo[ d]isoxazoles via Gold Catalysis
Xu, Wei,Zhao, Jidong,Li, Xiangdong,Liu, Yuanhong
, p. 15470 - 15485 (2019/01/04)
Benzo[d]isoxazoles are found to act as novel nucleophiles to undergo gold-catalyzed [5 + 1] or [5 + 2] cycloaddition reactions with ynamides. The reaction provides a concise and chemoselective access to polysubstituted 2H-benzo[e][1,3]oxazines or benzo[f][1,4]oxazepines. In addition, benzo[d]isoxazoles can also react with gold-carbene intermediates derived from propargyl esters to afford [5 + 1] annulation products.
Rhodium-catalyzed Synthesis of 1-Arylisoquinoline Derivatives through Annulative Coupling of 3-Aryl-1, 2-benzisoxazoles and Alkynes
Noguchi, Teppei,Nishii, Yuji,Miura, Masahiro
, p. 1512 - 1514 (2017/11/04)
Direct annulative coupling of 3-aryl-1, 2-benzisoxazoles and alkynes efficiently proceeds in the presence of a Cp?Rh(III) catalyst to produce 2-(1-isoquinolinyl)phenols of interest in medicinal chemistry as well as materials chemistry. The products may also be useful precursors of quinoline-based bidentate ligands.
A Novel PPh3 Mediated One-Pot Method for Synthesis of 3-Aryl or Alkyl 1,2-Benzisoxazoles
Chen, Guifang,Liu, Hong,Li, Shujia,Tang, Yu,Lu, Peiyao,Xu, Kaitian,Zhang, Yuanming
supporting information, p. 1792 - 1795 (2017/04/11)
A novel, efficient, and facile protocol has been developed for transforming 2-hydroxybenzonitriles and bromides into a range of 3-aryl or alkyl substituted 1,2-benzisoxazoles in good to excellent yields mediated by PPh3. The electronic and steric effects of bromides on the reaction are discussed. This is the first example to construct a C-C bond and heterocycle in a Barbier-Grignard-type reaction featuring easier recovery of PPh3 than a metallic catalyst in one step.
Palladium-catalyzed ortho-selective C-H bond chlorination of aromatic ketones
Shan, Gang,Huang, Gui-Yi,Rao, Yu,Zhang, Hui
, p. 1236 - 1240 (2015/12/31)
A palladium-catalyzed ortho-selective C-H bond chlorination reaction for the preparation of 2-chloro aromatic ketones was described. Both electron-withdrawing and electron-donating groups on the aromatic rings are well tolerated under the optimized conditions. The 2-chloro aromatic ketones obtained by our method could be applied to synthesize the derivatives of 1H-indazole or benzo[d]isoxazole.
Elemental step thermodynamics of various analogues of indazolium alkaloids to obtaining hydride in acetonitrile
Lei, Nan-Ping,Fu, Yan-Hua,Zhu, Xiao-Qing
supporting information, p. 11472 - 11485 (2015/12/04)
A series of analogues of indazolium alkaloids were designed and synthesized. The thermodynamic driving forces of the 6 elemental steps for the analogues of indazolium alkaloids to obtain hydride in acetonitrile were determined using an isothermal titration calorimeter (ITC) and electrochemical methods, respectively. The effects of molecular structure and substituents on the thermodynamic driving forces of the 6 steps were examined. Meanwhile, the oxidation mechanism of NADH coenzyme by indazolium alkaloids was examined using the chemical mimic method. The result shows that the oxidation of NADH coenzyme by indazolium alkaloids in vivo takes place by one-step concerted hydride transfer mechanism.
Hypervalent iodine-mediated synthesis of benzoxazoles and benzimidazoles via an oxidative rearrangement
Zhang, Xiaohui,Huang, Ruofeng,Marrot, Jér?me,Coeffard, Vincent,Xiong, Yan
, p. 700 - 708 (2015/02/02)
A Beckmann-type rearrangement of o-hydroxy and o-aminoaryl N-H ketimines has been developed to prepare benzoxazoles and N-Ts benzimidazoles, respectively. The ketimine derivatives were easily prepared by condensation of ammonia with the corresponding ketones and (diacetoxyiodo)benzene was found to act as an efficient oxidant to trigger the [1,2]-aryl migration towards the formation of the desired heterocycles. Depending on the substitution pattern, the results revealed another mechanistic pathway through which benzisoxazoles or 1H-indazoles could be formed. The Beckmann-type rearrangement strategy was applied to the synthesis of benzimidazole-containing biorelevant targets such as chlormidazole and clemizole.
Palladium-catalyzed benzo[d]isoxazole synthesis by C-H activation/[4 + 1] annulation
Duan, Pingping,Yang, Yunfang,Ben, Rong,Yan, Yiyong,Dai, Lu,Hong, Mei,Wu, Yun-Dong,Wang, Dongqi,Zhang, Xinhao,Zhao, Jing
, p. 1574 - 1578 (2014/03/21)
We report a palladium-catalyzed intermolecular [4 + 1] annulation pathway for N-phenoxyacetamides with aldehydes to form 1,2-benzisoxazoles. By activating the C-H bonds ortho to phenol-derived O-N bonds, the method enables the simultaneous construction of C-C and CN bonds in 1,2-benzisoxazoles with the O-N bonds intact. The method has been successfully applied to the synthesis of active pharmaceutical intermediates, such as risperidone.
Electrochemical reduction of 3-phenyl-1,2-benzisoxazole 2-oxide on boron-doped diamond
Kociolek, Martin,Bennett, Jason,Casbohm, Jerry
, p. 540 - 544 (2014/06/09)
The bioreduction of N-oxide compounds is the basis for the mode of action of a number of biologically active molecules. These compounds are thought to act by forming a reactive oxygen species through an intracellular reduction and subsequent redox cycling process within the organism. With these results in mind, the preliminary investigation into the electrochemical reduction of the benzisoxazole 2-oxide ring system was undertaken, with the thought that this class of compounds would reduce in a similar fashion to other N-oxide heterocycles. The electrochemical reduction of 3-phenyl-1,2-benzisoxazole 2-oxide on boron-doped diamond was studied using cyclic and square wave voltammetry as well as controlled potential electrolysis and HPLC for qualitative identification of the reaction products. It was found that the reduction proceeded with an initial quasi-reversible one-electron reduction followed by the very fast cleavage of either the endocyclic or exocyclic N-O bond. Subsequent electron transfer and protonation resulted in an overall two-electron reduction and formation of the 2-hydroxyaryl oxime and benzisoxazole. These results are analogous to those observed in the electrochemical reduction of other heterocyclic N-oxides albeit the reduction of the benzisoxazole N-oxides takes place at a more negative potential. However, these encouraging results warrant further investigation into the reduction potential of substituted benzisoxazole N-oxides as well as to elucidate and characterize the nature of the intermediate species involved.
A divergent and selective synthesis of isomeric benzoxazoles from a single N-Cl imine
Chen, Cheng-Yi,Andreani, Teresa,Li, Hongmei
supporting information; experimental part, p. 6300 - 6303 (2012/01/05)
A divergent and regioselective synthesis of either 3-substituted benzisoxazoles or 2-substituted benzoxazoles from readily accessible ortho-hydroxyaryl N-H ketimines is described. The reaction proceeds in two distinct pathways through a common N-Cl imine intermediate: (a) N-O bond formation to form benzisoxazole under anhydrous conditions and (b) NaOCl mediated Beckmann-type rearrangement to form benzoxazole, respectively. The reaction path also depends on the electronic nature of the aromatic ring, with the electron-rich aromatic rings favoring the rearrangement and the electron-deficient rings favoring the N-O bond formation. A Beckmann-type rearrangement mechanism via net [1,2]-aryl migration for the formation of 2-substituted benzoxazole is proposed.
