- Nickel-Catalyzed C-F/N-H Annulation of 2-(2-Fluoroaryl) N-Heteroaromatic Compounds with Alkynes: Activation of C-F Bonds
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The reaction of 2-(2-fluoroaryl) N-heteroaromatic compounds, such as benzimidazole and indole derivatives, with internal alkynes in the presence of a catalytic amount of a nickel complex results in C-F/N-H annulation with alkynes. The reaction shows a high functional group compatibility. The presence of a strong base, such as KOBu- tor LiOBu t, is required for the reaction to proceed.
- Kawakami, Haruka,Nohira, Itsuki,Chatani, Naoto
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- Rhodium(III)-Catalyzed Oxidative Annulation of Amidines with Alkynes via Sequential C?H Bond Activation
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In this paper, a rhodium-catalyzed sequential two-fold ortho-C?H functionalization of N-phenylbenzimidamide with internal alkyne is reported. The double C?H activations proved viable in a one-pot fashion with the assistance of C=N and C?N bonds, providing a series of benzimidazoisoquinolines with high levels of positional selectivity control. The operationally simple transformation showed high functional group compatibility and featured the cleavage of C?H bonds located on different a moiety of the N-phenylbenzimidamide substrates. Detailed mechanistic studies provided strong support for C?H bond cleavage on the N-phenyl ring to be preferential compared with C?H bond cleavage on C-phenyl ring. As a multifunctional catalytic platform, the rhodium catalyst conducted two independent and compatible catalytic cycles in one pot.
- Meng, Yan-Yu,Zhu, Wen-Jing,Song, Yuan-Yuan,Bu, Gang-Gang,Zhang, Li-Juan,Xu, Fen
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supporting information
p. 1290 - 1294
(2021/02/01)
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- Azaruthena(II)-bicyclo[3.2.0]heptadiene: Key Intermediate for Ruthenaelectro(II/III/I)-catalyzed Alkyne Annulations
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A ruthenium-catalyzed electrochemical dehydrogenative annulation reaction of imidazoles with alkynes has been established, enabling the preparation of various bridgehead N-fused [5,6]-bicyclic heteroarenes through regioselective electrochemical C?H/N?H annulation without chemical metal oxidants. Novel azaruthenabicyclo[3.2.0]heptadienes were fully characterized and identified as key intermediates. Mechanistic studies are suggestive of an oxidatively induced reductive elimination pathway within a ruthenium(II/III) regime.
- Ackermann, Lutz,Finger, Lars H.,Kuniyil, Rositha,Messinis, Antonis M.,Scheremetjew, Alexej,Steinbock, Ralf,Yang, Long
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supporting information
p. 11130 - 11135
(2020/05/18)
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- Nickel-catalyzed oxidative C-H/N-H annulation of N-heteroaromatic compounds with alkynes
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The reaction of N-heteroaromatic compounds, such as 2-aryl-pyrrole, benzimidazole, imidazole, indole, and pyrazole derivatives, with alkynes in the presence of a catalytic amount of a nickel complex results in C-H/N-H oxidative annulation. The reaction shows a high functional group compatibility. While both Ni(0) and Ni(ii) complexes show a high catalytic activity, Ni(0) is proposed as a key catalytic species in the main catalytic cycle. In the case of the Ni(ii) system, the presence of a catalytic amount of a strong base, such as KOBut, is required for the reaction to proceed. In sharp contrast, a base is not required in the case of the Ni(0) system. The proposed mechanism is supported by DFT studies.
- Obata, Atsushi,Sasagawa, Akane,Yamazaki, Ken,Ano, Yusuke,Chatani, Naoto
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p. 3242 - 3248
(2019/03/21)
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- Nickel-Catalyzed Annulation of o-Haloarylamidines with Aryl Acetylenes: Synthesis of Isoquinolone and 1-Aminoisoquinoline Derivatives
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An efficient method for the synthesis of substituted 1(2H)-isoquinolone derivatives via nickel-catalyzed annulation of substituted 2-halobenzamidines with aryl alkynes in the presence of water is described. Benzo[4,5]imidazo[2,1-a]isoquinolines were formed as the dominated products when dry dimethyl sulfoxide was used as the solvent. Furthermore, when benzyl substituted amidines were used as the substrates, debenzylation reaction occured to provide various 1-aminoisoquinoline products. (Figure presented.).
- Xie, Hao,Xing, Qiaoyan,Shan, Zhifei,Xiao, Fuhong,Deng, Guo-Jun
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supporting information
p. 1896 - 1901
(2019/03/07)
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- (Benz)Imidazole-Directed Cobalt(III)-Catalyzed C–H Activation of Arenes: A Facile Strategy to Access Polyheteroarenes by Oxidative Annulation
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A facile cobalt(III) catalyzed C–H activation of arenes with substituted (benz)imidazoles as directing groups (DG) is reported. The strategy was utilized for the synthesis of polyheteroarenes when appropriate substrates were treated with diarylacetylenes as the coupling partner. The desired compounds were synthesized in moderate to excellent yield. A putative reaction mechanism is proposed. The final compounds revealed photoluminescence properties.
- Dutta, Pratip Kumar,Sen, Subhabrata
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p. 5512 - 5519
(2018/10/24)
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- N-Doped Cationic PAHs by Rh(III)-Catalyzed Double C-H Activation and Annulation of 2-Arylbenzimidazoles with Alkynes
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A novel class of N-doped cationic PAHs (polycyclic aromatic hydrocarbons) bearing the benzo[c,d]fluoranthene scaffold has been synthesized by the Rh(III)-catalyzed double-oxidative annulation of 2-arylbenzimidazoles with alkynes. The overall process involves a double C-N bond formation through a double C-H/N-H functionalization.The solid-state structures and electronic properties of the new N-doped PAHs were analyzed. These cationic azapolycycles were readily reduced in the presence of LiAlH4 or by the addition of PhLi to give interesting phenyl and diphenylmethanediamine derivatives.
- Villar, José M.,Suárez, Jaime,Varela, Jesús A.,Saá, Carlos
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supporting information
p. 1702 - 1705
(2017/04/11)
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- Metal complexes
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The present invention relates to metal complexes and to electronic devices, in particular organic electroluminescent devices, comprising these metal complexes.
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Page/Page column 113; 114
(2016/10/10)
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- Ruthenium catalyzed oxidative annulation with alkynes via cascade C-H/N-H bond functionalizations
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Ruthenium(II) complexes catalyzed tandem C-H/N-H bonds functionalizations of 2-phenyl imidazole and its derivatives with alkynes were realized. This transformations allowed for rapid synthesis of isoquinoline derivatives under open-flask condition. Publis
- Wang, Rui,Falck
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supporting information
p. 33 - 36
(2014/04/03)
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- Ruthenium-catalyzed benzimidazoisoquinoline synthesis via oxidative coupling of 2-arylbenzimidazoles with alkynes
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Synthesis of a fused bis-heterocyclic framework, benzimidazoisoquinoline, has been achieved using Ru-catalyzed reaction of alkynes with 2-aryl benzimidazoles in the presence of Cu salts. The method provides an easy access for the generation of a library of benzimidazoisoquinoline derivatives.
- Kavitha, Nerella,Sukumar, Genji,Kumar, Vemula Praveen,Mainkar, Prathama S.,Chandrasekhar, Srivari
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p. 4198 - 4201
(2013/07/26)
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- CuI/I2-promoted electrophilic tandem cyclization of 2-ethynylbenzaldehydes with ortho -benzenediamines: Synthesis of iodoisoquinoline-fused benzimidazoles
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An efficient tandem route to the synthesis of iodoisoquinoline-fused benzimidazole derivatives including an iodocyclization strategy has been developed. In the presence of CuI, a variety of 2-ethynylbenzaldehydes underwent the tandem reaction with benzenediamines and iodine to afford the corresponding iodoisoquinoline-fused benzimidazoles in moderate to good yields.
- Ouyang, Huang-Che,Tang, Ri-Yuan,Zhong, Ping,Zhang, Xing-Guo,Li, Jin-Heng
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p. 223 - 228
(2011/03/18)
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- Fluorescent naphthyl- and anthrylazoles from the catalytic coupling of phenylazoles with internal alkynes through the cleavage of multiple C-H bonds
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(Chemical Equation Presented) Bright light rings: The direct coupling of phenylazoles with an internal alkyne proceeds efficiently in the presence of a rhodium catalyst and a copper oxidant to selectively give either the 1-naphthyl- or 1-anthrylazole derivatives through the cleavage of multiple C-H bonds (see scheme; 1-naphthylazole derivative not shown). Some of the products exhibit intense fluorescence in the solid state.
- Umeda, Nobuyoshi,Tsurugi, Hayato,Satoh, Tetsuya,Miura, Masahiro
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supporting information; experimental part
p. 4019 - 4022
(2009/02/08)
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