- New aspects of the aromatic photosubstitution with iodopyridines
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Reactive entities in the photoreaction of 2-, 3- and 4-iodopyridines with substituted benzenes were investigated; 3- and 4-pyridylation could be explained in terms of radical reaction, while the 2-pyridyl cation was an important intermediate in the 2-pyridylation. The importance of the unshared electron pair of the nitrogen adjacent to the radical carbon for the conversion of the 2-pyridyl radical initially produced into the cation is discussed on the basis of molecular orbital (MO) calculations.
- Ohkura,Terashima,Kanaoka,Seki
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Read Online
- Cp*Rh(iii)/boron hybrid catalysis for directed C-H addition to β-substituted α,β-unsaturated carboxylic acids
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The C-H bond addition reaction of 2-phenylpyridine derivatives with α,β-unsaturated carboxylic acids catalyzed by Cp*Rh(iii)/BH3·SMe2is reported. Activation of C-H bonds with the rhodium catalyst and activation of α,β-unsaturated carboxylic acids with the boron catalyst cooperatively work, and a BINOL-urea hybrid ligand significantly improved the reactivity. With the optimized hybrid catalytic system, various β-disubstituted carboxylic acids were obtained under mild reaction conditions.
- Hirata, Yuki,Kojima, Masahiro,Matsunaga, Shigeki,Tanaka, Ryo,Yoshino, Tatsuhiko
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supporting information
p. 76 - 79
(2021/12/29)
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- Access to Branched Allylarenes via Rhodium(III)-Catalyzed C-H Allylation of (Hetero)arenes with 2-Methylidenetrimethylene Carbonate
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A rhodium(III)-catalyzed C-H allylation of (hetero)arenes by using 2-methylidenetrimethylene carbonate as an efficient allylic source has been developed for the first time. Five different directing groups including oxime, N-nitroso, purine, pyridine, and pyrimidine were compatible, delivering various branched allylarenes bearing an allylic hydroxyl group in moderate to excellent yields.
- Zhang, Shang-Shi,Zheng, Yi-Chuan,Zhang, Zi-Wu,Chen, Shao-Yong,Xie, Hui,Shu, Bing,Song, Jia-Lin,Liu, Yan-Zhi,Zeng, Yao-Fu,Zhang, Luyong
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supporting information
p. 5719 - 5723
(2021/08/16)
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- Chromium-Catalyzed Reductive Cleavage of Unactivated Aromatic and Benzylic C-O Bonds
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Reductive cleavage of aromatic and benzylic C-O bonds by chromium catalysis is reported. This deoxygenative reaction was promoted by low-cost CrCl 2precatalyst combined with poly(methyl hydrogen siloxane) as the mild reducing agent, providing a strategy in forming reduced motifs by cleavage of unactivated C-O bonds. A range of functional groups such as bromide, chloride, fluoride, hydroxyl, amino, and alkoxycarbonyl can be retained in the reduction.
- Yuan, Shuqing,Ling, Liang,Tang, Jinghua,Luo, Meiming,Zeng, Xiaoming
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p. 3343 - 3350
(2021/07/02)
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- Multicomponent Aromatic and Benzylic Mannich Reactions through C?H Bond Activation
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Multicomponent Mannich reactions through C?H bond activation are described. These transformations allowed for the straightforward generation of densely substituted benzylic and homo-benzylic amines in good yields. The reaction involves a reaction between two transient species: an organometallic species, generated by transition-metal-catalyzed sp2 or sp3 C?H bond activation and an in situ generated imine. The use of an acetal as an aldehyde surrogate was found essential for the reaction to proceed. The process could be successfully applied to RhIII-catalyzed sp2 C?H bond functionalization and extended to CuII-catalyzed sp3 C?H bond functionalization.
- Xavier, Tania,Rayapin, Corinne,Le Gall, Erwan,Presset, Marc
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supporting information
p. 13824 - 13828
(2019/11/03)
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- BLUE AND NARROW BAND GREEN AND RED EMITTING METAL COMPLEXES
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The present invention includes tetradentate platinum (II) complexes for narrow band green and red phosphorescent emitters. The present invention also includes blue emitting metal complexes with six-membered chelate rings based on fused carbazole. The pres
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Paragraph 0082; 0084
(2019/09/20)
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- SPIRO-CONTAINING PLATINUM (II) EMITTERS WITH TUNABLE EMISSION ENERGIES AND SYNTHESES THEREOF
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An asymmetric tetradentate metal complex of a N^C^C^N comprising tetradentate ligand has a metal connected to binding sites which are connected to each other via three or four covalent bonds that can be either single or double bonds with bridging linkers reside between C^C and C^N moieties. These linkers result in three-dimension metal complexes with distorted square planar geometries. The four donor atoms coordinate to a metal center. Upon metal binding a 5-6-6 membered metallocycle is formed upon chelation including a first nitrogen donor bond, a first metal-carbon bond, a second metal-carbon bond, and a second nitrogen donor bond. The light emission from these metal complexes can be tuned by the ligand structure over the entire visible spectrum.
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Page/Page column 18
(2019/08/12)
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- Ruthenium-Catalyzed ortho- And meta-H/D Exchange of Arenes
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Ruthenium-catalyzed aromatic H/D exchange in [D4]acetic acid has been developed. By using N-heteroarenes as directing groups, both ortho and meta positions are selectively deuterated with high levels of D incorporation. Moreover, this strategy provides an alternative way to achieve meta-C-H activation.
- Zhao, Liang-Liang,Liu, Wei,Zhang, Zengyu,Zhao, Hongyan,Wang, Qi,Yan, Xiaoyu
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supporting information
p. 10023 - 10027
(2019/12/24)
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- Photoarylation of Pyridines Using Aryldiazonium Salts and Visible Light: An EDA Approach
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A metal-free methodology for the photoarylation of pyridines, in water, is described giving 2 and 4-arylated-pyridines in yields up to 96percent. The scope of the aryldiazonium salts is presented showing important results depending on the nature and position of the substituent group in the diazonium salt, that is, electron-donating or electron-withdrawing in the ortho, meta, or para positions. Further heteroaromatics were also successfully photoarylated. Mechanistic studies and comparison between our methodology and similar metal-catalyzed procedures are presented, suggesting the occurrence of a visible-light EDA complex which generates the aryl radical with no need for an additional photocatalyst.
- Bartolomeu, Aloisio De A.,Brocksom, Timothy J.,De Oliveira, Kleber T.,No?l, Timothy,Silva, Rodrigo C.
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- Dibenzofuran and dibenzothiophene based palladium(ii)/NHC catalysts-synthesis and applications in C-C bond formation
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In the quest for a new ligand system for Pd(ii)/NHCs, we developed new dibenzofuran and dibenzothiophene based palladium N-heterocyclic carbene catalysts D1-D6 in good yields. All the catalysts were characterized by multinuclear NMR spectroscopy and HRMS. The X-ray crystal structure of the representative dibenzothiophene based Pd(ii)/NHC D4 was determined. Among the precatalysts, D1 was shown to be highly effective in the Suzuki-Miyaura cross-coupling reaction of heterocyclic bromides with boronic acids. Besides, D1 affords diverse arylated benzoxazoles via direct C-H bond functionalization with substituted bromo derivatives.
- Karthik, Shanmugam,Gandhi, Thirumanavelan
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supporting information
p. 15811 - 15819
(2018/10/04)
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- NCP ligand, [...] complex, synthesis method, intermediate and application
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The invention discloses an NCP ligand, iridium complex, synthetic method, intermediate and application thereof. The invention provides an NCP ligand and an NCP ligand iridium complex, wherein R1, R2, R3, R4, R5, R6 and R7 separately represent hydrogen atom or C1-C30 alkyl, R' and R'' independently represent C1-C30 alkyl. The invention provides the application of the NCP ligand iridium complex to the catalysis of alkane dehydrogenation reaction, olefin isomerization reaction, alcohol dehydrogenation reaction, ester alpha alkylation reaction, and amide alpha alkylation reaction. The NCP ligand provided by the invention contains dialkyl substituted phosphine, which has strong electron donating ability and can form a NCP ligand iridium complex by complexing with iridium. The NCP ligand iridium complex uses pyridine to replace a conventional alkyl phosphate electron donor, and has the advantages of good stability, high selectivity on alkane dehydrogenation reaction, mild reaction conditions, good catalytic effect, and industrial production prospect.
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Paragraph 0043; 0156-0158
(2018/07/30)
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- Spin-Center Shift-Enabled Direct Enantioselective α-Benzylation of Aldehydes with Alcohols
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Nature routinely engages alcohols as leaving groups, as DNA biosynthesis relies on the removal of water from ribonucleoside diphosphates by a radical-mediated "spin-center shift" (SCS) mechanism. Alcohols, however, remain underused as alkylating agents in synthetic chemistry due to their low reactivity in two-electron pathways. We report herein an enantioselective α-benzylation of aldehydes using alcohols as alkylating agents based on the mechanistic principle of spin-center shift. This strategy harnesses the dual activation modes of photoredox and organocatalysis, engaging the alcohol by SCS and capturing the resulting benzylic radical with a catalytically generated enamine. Mechanistic studies provide evidence for SCS as a key elementary step, identify the origins of competing reactions, and enable improvements in chemoselectivity by rational photocatalyst design.
- Nacsa, Eric D.,MacMillan, David W. C.
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supporting information
p. 3322 - 3330
(2018/03/13)
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- Direct Alkenylation of Allylbenzenes via Chelation-Assisted C-C Bond Cleavage
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A novel method for direct transformation of allyl groups in allylbenzene derivatives to alkenyl groups via rhodium-catalyzed C-C bond cleavage is reported. The alkenylation with styrenes of allylbenzenes containing pyridyl and pyrazolyl groups as a directing group proceeded efficiently to give alkenylation products. We also developed a new protocol for transformation of an ortho-prenylated phenol to an aniline derivative.
- Onodera, Shunsuke,Ishikawa, Soya,Kochi, Takuya,Kakiuchi, Fumitoshi
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supporting information
p. 9788 - 9792
(2018/05/31)
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- Multi-tooth type dinuclear cyclic metal complex containing 2-phenylpyridine and derivative of 2-phenylpyridine
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The invention relates to a multi-tooth type dinuclear cyclic metal complex containing 2-phenylpyridine and a derivative of 2-phenylpyridine. The multi-tooth type dinuclear cyclic metal complex is suitable for using as light emitting materials or main mate
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Paragraph 0154
(2017/12/27)
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- Palladium-catalyzed C-H alkylation of 2-phenylpyridines with alkyl iodides
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Palladium-catalyzed C-H alkylation reaction of 2-phenylpyridines with alkyl iodides has been successfully developed. The palladacycles obtained from 2-phenylpyridines should act as the key intermediates in the alkylation reaction.
- Wang, Xiaoling,Ji, Xiaoming,Shao, Changdong,Zhang, Yu,Zhang, Yanghui
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supporting information
p. 5616 - 5624
(2017/07/12)
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- Copper-mediated C-H cyanation of (hetero)arenes with ethyl (ethoxymethylene)cyanoacetate as a cyanating agent
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A copper-mediated direct C-H cyanation of (hetero)arenes with ethyl (ethoxymethylene)cyanoacetate as a safe cyanating agent has been successfully developed by using molecular oxygen as the oxidant. The reaction tolerates a variety of functional groups and provides a facile and efficient method for the synthesis of a wide range of (hetero)aryl nitriles.
- Qi, Chaorong,Hu, Xiaohan,Jiang, Huanfeng
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p. 7994 - 7997
(2017/07/22)
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- Palladium-catalyzed decarboxylative, decarbonylative and dehydrogenative C(sp2)-H acylation at room temperature
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Over the past few decades, an impressive array of C-H activation methodology has been developed for organic synthesis. However, due to the inherent inertness of the C-H bonds (e.g. ~110 kcal mol-1 for the cleavage of C(aryl)-H bonds) harsh reaction conditions have been realized to overcome high energetic transition states resulting in a limited substrate scope and functional group tolerance. Therefore, the development of mild C-H functionalization protocols is in high demand to exploit the full potential of the C-H activation strategy in the synthesis of a complex molecular framework. Although, electron-rich substrates undergo electrophilic metalation under relatively mild conditions, electron-deficient substrates proceed through a rate-limiting C-H insertion under forcing conditions at high temperature. In addition, a stoichiometric amount of toxic silver salt is frequently used in palladium catalysis to facilitate the C-H activation process which is not acceptable from the environmental and industrial standpoint. We report herein, a Pd(ii)-catalyzed decarboxylative C-H acylation of 2-arylpyridines with α-ketocarboxylic acids under mild conditions. The present protocol does not require stoichiometric silver(i) salts as additives and proceeds smoothly at ambient temperature. A novel decarbonylative C-H acylation reaction has also been accomplished using aryl glyoxals as acyl surrogates. Finally, a practical C-H acylation via a dehydrogenative pathway has been demonstrated using commercially available benzaldehydes and aqueous hydroperoxides. We also disclose that acetonitrile solvent is optimal for the acylation reaction at room temperature and has a prominent role in the reaction outcome. Control experiments suggest that the acylation reaction via decarboxylative, decarbonylative and dehydrogenative proceeds through a radical pathway. Thus we disclose a practical protocol for the sp2 C-H acylation reaction.
- Hossian, Asik,Manna, Manash Kumar,Manna, Kartic,Jana, Ranjan
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supporting information
p. 6592 - 6603
(2017/08/16)
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- Pyridine sulfinates as general nucleophilic coupling partners in palladium-catalyzed cross-coupling reactions with aryl halides
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Pyridine rings are ubiquitous in drug molecules; however, the pre-eminent reaction used to form carbon-carbon bonds in the pharmaceutical industry, the Suzuki-Miyaura cross-coupling reaction, often fails when applied to these structures. This phenomenon is most pronounced in 2-substituted pyridines, and results from the difficulty in preparing, the poor stability of, and low efficiency in reactions of pyridine-2-boronates. We demonstrate that by replacing these boronates with pyridine-2-sulfinates, a cross-coupling process of unrivalled scope and utility is realized. The corresponding 3-And 4-substituted pyridine variants are also efficient coupling partners. In addition, we apply these sulfinates in a library format to the preparation of medicinally relevant derivatives of the drugs varenicline (Chantix) and mepyramine (Anthisan).
- Markovic, Tim,Rocke, Benjamin N.,Blakemore, David C.,Mascitti, Vincent,Willis, Michael C.
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p. 4437 - 4442
(2017/07/11)
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- Metal complex, preparation method thereof and application of metal complex in organic electroluminescence devices
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The invention discloses metal complex and application thereof in organic electroluminescence devices. The general formula of the metal complex is as shown in the specification, wherein A is selected from substituted or non-substituted C6-C60 aryl groups,
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Paragraph 0072; 0073; 0074
(2017/10/07)
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- Synthesis of 2-phenyl pyridine derivatives from aryl ketones and 1,3-diaminopropane using palladium acetate as a catalyst
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A simple and efficient method for the synthesis of 2-phenyl pyridine via cyclization of aryl ketone with 1,3-diaminopropane using palladium acetate is established. This method is mild, operationally simple, involves short reaction time and involves easy workup procedure to afford the corresponding 2-phenyl pyridines in moderate to good yield.
- Ghodse, Shrikant M.,Telvekar, Vikas N.
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supporting information
p. 524 - 526
(2017/01/17)
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- Blue light mediated C-H arylation of heteroarenes using TiO2 as an immobilized photocatalyst in a continuous-flow microreactor
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Titanium dioxide was applied as an immobilized photocatalyst in a microstructured falling film reactor for the continuous-flow C-H arylation of heteroarenes with aryldiazonium salts as the starting material. Detailed investigations of the catalyst and a successful long-term run proved its excellent usability for this process. Very good yields up to 99% were achieved with broad substrate scope and were compared with batch synthesis. The transfer to the continuous-flow mode revealed an impressive boost in reactor performance solely resulting from the improved irradiation and contact of the catalyst, substrate and light.
- Fabry, David C.,Ho, Yee Ann,Zapf, Ralf,Tremel, Wolfgang,Panth?fer, Martin,Rueping, Magnus,Rehm, Thomas H.
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supporting information
p. 1911 - 1918
(2017/06/09)
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- Palladium catalyzed ortho-C-H-acylation of 2-arylpyridines using phenylacetylenes and styrene epoxide
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A palladium-catalyzed ortho-C-H-acylation of 2-arylpyridine using phenylacetylenes and styrene epoxide as the acylated reagents was developed. With the employment of tert-butyl hydroperoxide (TBHP) as the oxidant and a phosphorous ligand, the protocol generates corresponding aryl ketones in moderated to good yields with high regioselectivity and good functional group compatibility.
- Zhang, Qian,Wang, Yang,Yang, Tingting,Li, Li,Li, Dong
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supporting information
p. 90 - 94
(2015/12/23)
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- Chelation-Assisted Copper-Mediated Direct Acetylamination of 2-Arylpyridine C-H Bonds with Cyanate Salts
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In this study, the coupling of 2-phenylpyridine derivatives and potassium cyanate through C-H bond functionalization in the presence of a copper salt is developed for the first time. By this protocol, various heteroarylated acetanilide derivatives are synthesized in good yields. 2-Phenylpyridines containing electron-donating and -withdrawing groups appear to be well-tolerated by this transformation.
- Kianmehr, Ebrahim,Amiri Lomedasht, Yousef,Faghih, Nasser,Khan, Khalid Mohammed
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p. 6087 - 6092
(2016/07/23)
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- Highly luminescent palladium(II) complexes with sub-millisecond blue to green phosphorescent excited states. Photocatalysis and highly efficient PSF-OLEDs
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Palladium(ii) complexes supported by tetradentate [N^C^C^N] and [O^N^C^N] ligand systems display sky blue to red phosphorescence with emission quantum yields and emission lifetimes up to 0.64 and 272 μs, respectively. Femtosecond time-resolved fluorescenc
- Chow, Pui-Keong,Cheng, Gang,Tong, Glenna So Ming,Ma, Chensheng,Kwok, Wai-Ming,Ang, Wai-Hung,Chung, Clive Yik-Sham,Yang, Chen,Wang, Feng,Che, Chi-Ming
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p. 6083 - 6098
(2016/09/03)
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- Visible light-induced aerobic C-N bond activation: A photocatalytic strategy for the preparation of 2-arylpyridines and 2-arylquinolines
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An efficient method for accessing arylpyridines and arylquinolines via visible light-induced aerobic C-N bond activation is described. The applicability of different kinds of simple ketones, easily available amines, and the use of air as the sole oxidant make this transformation very attractive.
- Hu, Bei,Li, Yuyuan,Dong, Wuheng,Xie, Xiaomin,Wan, Jun,Zhang, Zhaoguo
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p. 48315 - 48318
(2016/06/09)
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- Cationic platinum(II) complexes bearing aryl-BIAN ligands: Synthesis and structural and optoelectronic characterization
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Five cationic platinum(II) complexes bearing a 2-(3′-substituted aryl)pyridine cyclometalating ligand (C^N) and a neutral Ar-BIAN ligand have been synthesized: [Pt(ppy)(PhBIAN)]PF6 (1), [Pt(3Fppy)(PhBIAN)]PF6 (2), [Pt(3MeOppy)(PhBIAN)]PF6 (3), [Pt(3MeOppy)(4-FPhBIAN)]PF6 (4), [Pt(ppy)(4-MeOPhBIAN)]PF6 (5). All complexes have been characterized by NMR spectroscopy and mass spectrometry. Complexes 2 and 3 have been characterized by X-ray crystallography. Structure-property relationships were established from UV-visible spectroscopy and cyclic voltammetry studies. Interestingly, we found that when both the C^N and the Aryl-BIAN ligands contained electron-donating MeO groups the absorption spectrum for the platinum complex extended out to 650 nm. The electrochemical studies of these complexes established that they are electronically compatible dye molecules for dye-sensitized solar cells.
- Obrien, Cameron,Wong, Michael Yin,Cordes, David B.,Slawin, Alexandra M. Z.,Zysman-Colman, Eli
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- Cobalt-catalyzed C-H cyanation of (Hetero)arenes and 6-Arylpurines with N -cyanosuccinimide as a new cyanating agent
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A cobalt-catalyzed C-H cyanation reaction of arenes has been developed using N-cyanosuccinimide as a new electrophilic cyanating agent. The reaction proceeds with high selectivity to afford monocyanated products with excellent functional group tolerance. Substrate scope was found to be broad enough to include a wide range of heterocycles including 6-arylpurines.
- Pawar, Amit B.,Chang, Sukbok
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supporting information
p. 660 - 663
(2015/03/04)
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- 2-catalyzed directed N -Boc amidation of arenes "on water"
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Rhodium(III) catalysis "on water" is effective for directed C-H amidation of arenes. The catalytic process is promoted by OH groups present on the hydrophobic water surface and is inefficient in all (most) common organic solvents investigated so far. In the presence of easily prepared tert-butyl 2,4-dinitrophenoxycarbamate, a new and stable nitrene source, the "on water" reaction can efficiently provide the desired N-Boc-aminated products with good functional group tolerance.
- Ali, Md Ashif,Yao, Xiayin,Sun, Hao,Lu, Hongjian
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supporting information
p. 1513 - 1516
(2015/03/30)
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- Cobalt(III)-Catalyzed Directed C-H Coupling with Diazo Compounds: Straightforward Access towards Extended π-Systems
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The first highly efficient and scalable cobalt-catalyzed directed C-H functionalization with carbene precursors is presented. This methodology provides a modular route towards a new class of conjugated polycyclic hydrocarbons with tunable emission wavelengths both in solution and in the solid state.
- Zhao, Dongbing,Kim, Ju Hyun,Stegemann, Linda,Strassert, Cristian A.,Glorius, Frank
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supporting information
p. 4508 - 4511
(2015/04/14)
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- RhIII-Catalyzed C-H Activation with Pyridotriazoles: Direct Access to Fluorophores for Metal-Ion Detection
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The first C-H bond activation with pyridotriazoles as coupling partners is presented using a RhIII catalyst. The pyridotriazoles can be used as new carbene precursors in C-H activation for direct access to novel fluorescent scaffolds. These tunable fluorophores can be applied for the detection of metal ions.
- Kim, Ju Hyun,Gensch, Tobias,Zhao, Dongbing,Stegemann, Linda,Strassert, Cristian A.,Glorius, Frank
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supporting information
p. 10975 - 10979
(2015/09/15)
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- Palladium catalyzed ortho-C-H-benzoxylation of 2-arylpyridines using iodobenzene dibenzoates
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A palladium-catalyzed ortho-C-H-benzoxylation of 2-arylpyridines using iodobenzene dibenzoates has been developed. The reaction employed the stable and easily accessible hypervalent iodine reagents as both benzoxylate source and oxidant which made the protocol simple and facile. It showed high regioselectivity and good functional group tolerance, and gave the mono-benzoxylation products in moderate to excellent yields.
- Zhang, Qian,Wang, Ying,Yang, Tingting,Li, Li,Li, Dong
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supporting information
p. 6136 - 6141
(2015/10/28)
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- Cobalt(III)-Catalyzed Functionalization of Unstrained Carbon-Carbon Bonds through β-Carbon Cleavage of Alcohols
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We demonstrate that a simple Co(III)-complex can efficiently catalyze the cleavage of unstrained C-C bonds via the β-carbon elimination of secondary and tertiary alcohols bearing a directing group. The cobalt-aryl intermediate generated under the reaction conditions can be trapped by different electrophiles to generate a new carbon-carbon bond. Some essential features of this new Co-based mechanistic manifold were revealed by preliminary mechanistic studies.
- Ozkal, Erhan,Cacherat, Bastien,Morandi, Bill
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p. 6458 - 6462
(2015/11/23)
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- Cross-coupling study of iodo/chloropyridines and 2-chloroquinoline with atom-economic triarylbismuth reagents under Pd-catalysis
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This study describes the palladium-catalyzed couplings of iodopyridines, chloropyridines, and chloroquinoline with atom-economic BiAr3 reagents in sub-stoichiometric loadings. Mono-arylations of iodo and chloropyridines produced arylpyridines i
- Rao, Maddali L.N.,Dhanorkar, Ritesh J.
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p. 338 - 349
(2015/03/04)
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- Aerobic C-N bond activation: A simple strategy to construct pyridines and quinolines
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Inspired by the autoxidation processes, a dioxygen induced C-N bond activation of primary alkyl amines was demonstrated toward the synthesis of pyridines and quinolines. The transition-metal free conditions with O2 as the sole oxidant make this transformation very attractive. Notably, the substrate applicability of different kinds of ketones is greatly broadened for this transformation.
- Wu, Kun,Huang, Zhiliang,Liu, Chao,Zhang, Heng,Lei, Aiwen
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supporting information
p. 2286 - 2289
(2015/02/05)
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- Direct arylation of pyridines without the use of a transition metal catalyst
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A method for achieving the direct arylation of pyridines with phenylhydrazine hydrochloride was developed in this study. This new reaction proceeds readily at room temperature without the use of any transition metal catalysts. This method allows rapid access to various arylated heterocycles that are more difficult to access through traditional methods.
- Li, Yahui,Liu, Wei,Kuang, Chunxiang
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supporting information
p. 7124 - 7127
(2014/07/07)
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- Iridium complexes of new NCP pincer ligands: Catalytic alkane dehydrogenation and alkene isomerization
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Iridium complexes of novel NCP pincer ligands containing pyridine and phosphinite arms have been synthesized. One Ir complex shows good catalytic activity for alkane dehydrogenation, and all complexes are highly active for olefin isomerization. A combination of the Ir complex and a (PNN)Fe pincer complex catalyzes the formation of linear alkylboronates selectively from internal olefins via sequential olefin isomerization-hydroboration. This journal is the Partner Organisations 2014.
- Jia, Xiangqing,Zhang, Lei,Qin, Chuan,Leng, Xuebing,Huang, Zheng
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supporting information
p. 11056 - 11059
(2014/09/30)
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- Multicomponent [5 + 2] cycloaddition reaction for the synthesis of 1,4-diazepines: Isolation and reactivity of azomethine ylides
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Air-stable azomethine ylides with an unusual pattern of charge distribution were efficiently prepared via the rhodium-catalyzed reaction between pyridines and 1-sulfonyl-1,2,3-triazoles. This reaction allowed for the first example of the catalytic multicomponent [5 + 2] cycloaddition reactions, thus resulting in the formation of biologically active 1,4-diazepine compounds.
- Lee, Dong Jin,Han, Hong Sik,Shin, Jinhwan,Yoo, Eun Jeong
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supporting information
p. 11606 - 11609
(2014/10/15)
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- Palladium-catalyzed trifluoromethylthiolation of aryl C-H bonds
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A method for monotrifluoromethylthiolation of arenes via palladium-catalyzed directed C-H bond activation was described. The reaction was compatible with a variety of functional groups. Initial mechanistic studies disclosed that the turnover limiting step of the catalytic cycle did not involve C-H activation.
- Xu, Chunfa,Shen, Qilong
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supporting information
p. 2046 - 2049
(2014/05/06)
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- Cu-catalyzed direct amidation of aromatic C-H bonds: An access to arylamines
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A Cu-catalyzed aromatic C-H amidation with phthalimide under oxygen as a terminal oxidant without using additional additives has been achieved. This reaction has the broad substrate scope and shows moderate to good yields in most cases. This method is complementary to the previously reported metal-catalyzed C-H amination systems.
- Xu, Hui,Qiao, Xixue,Yang, Shiping,Shen, Zengming
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p. 4414 - 4422
(2014/06/09)
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- Asymmetric Hydrogenation of Pyridinium Salts with an Iridium Phosphole Catalyst
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Iridium-catalyzed asymmetric hydrogenation of N-alkyl-2-alkylpyridinium salts provided 2-aryl-substituted piperidines with high levels of enantioselectivity. Simple benzyl and other alkyl groups successfully activated the challenging pyridine substrates toward hydrogenation. The use of the unusual chiral-phosphole-based MP2-SEGPHOS was the key to the success of this approach which provides a versatile and practical procedure for the synthesis of chiral piperidines. Ring to ring: Simple N-benzyl and N-alkyl groups successfully activated pyridine substrates toward hydrogenation. The use of the unusual chiral phosphole-based ligand L was the key to the success of this approach, which provides a versatile and practical procedure for the synthesis of chiral piperidines. cod=1,5-cyclooctadiene.
- Chang, Mingxin,Huang, Yuhua,Liu, Shaodong,Chen, Yonggang,Krska, Shane W.,Davies, Ian W.,Zhang, Xumu
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supporting information
p. 12761 - 12764
(2016/02/18)
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- Copper-catalyzed aerobic synthesis of 2-arylpyridines from acetophenones and 1,3-diaminopropane
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A copper-catalyzed reaction providing direct access to 2-arylpyridines from acetophenones and 1,3-diaminopropane is described. A range of electronically diverse acetophenones undergo this transformation, affording 2-arylpyridines in good yields. (Chemical Equation Presented).
- Xi, Long-Yi,Zhang, Ruo-Yi,Liang, Shuai,Chen, Shan-Yong,Yu, Xiao-Qi
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supporting information
p. 5269 - 5271
(2015/01/09)
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- Triarylbismuthanes as threefold aryl-transfer reagents in regioselective cross-coupling reactions with bromopyridines and quinolines
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Cross-coupling studies using bromopyridines and bromoquinolines with triarylbismuths as threefold coupling reagents in substoichiometric amounts under Pd-catalysed conditions are disclosed. The reactivity was high with both mono- and dibromopyridyl substrates, and mono- and bis-couplings were carried out regioselectively. A library of monoaryl and diaryl pyridines was formed in high yields. A one-pot strategy provided a simple and straightforward synthesis of both symmetrical and unsymmetrical diarylpyridines. Arylations of 2-bromo- and 3-bromoquinolines were achieved with triarylbismuth reagents. This study demonstrates that triarylbismuths may be used as threefold arylating reagents for the synthesis of aryl pyridines and quinolines through couplings with bromopyridines and bromoquinolines under Pd-catalysed conditions. Copyright
- Rao, Maddali L.N.,Dhanorkar, Ritesh J.
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supporting information
p. 5214 - 5228
(2014/10/15)
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- Synthesis of heteroaryl compounds through cross-coupling reaction of aryl bromides or benzyl halides with thienyl and pyridyl aluminum reagents
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An efficient method for synthesis of useful biaryl building blocks containing 2-thienyl, 3-thienyl, 2-pyridyl, and 3-pyridyl moieties was provided through cross-coupling reactions of aryl bromides or benzyl halides with heteroaryl aluminum reagents in the presence of Pd(OAc)2 and (o-tolyl)3P. The coupling reaction also worked efficiently with heteroaryl bromides affording series of heterobiaryl compounds. The reaction of phenylbromide with in situ prepared 3-pyridyl aluminum was demonstrated to afford the product 8a in high yield. Additionally, the catalytic system was also suited well for the coupling reaction of benzyl halides with pyridyl aluminum reagents to afford series of pyridyl-arylmethane.
- Chen, Xu,Zhou, Lingmin,Li, Yimei,Xie, Tao,Zhou, Shuangliu
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p. 230 - 239
(2014/01/17)
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- Arylation of 2-substituted pyridines via Pd-catalyzed decarboxylative cross-coupling reactions of 2-picolinic acid
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The novel palladium-catalyzed decarboxylative cross-coupling reactions of 2-picolinic acid with aryl and heteroaryl bromides including benzenes, naphthalenes, pyridines and quinolines for C-C bond formation have been successfully achieved. This journal is
- Li, Xinjian,Zou, Dapeng,Leng, Faqiang,Sun, Chunxia,Li, Jingya,Wu, Yangjie,Wu, Yusheng
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supporting information
p. 312 - 314
(2013/02/22)
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- Copper-catalyzed aromatic C-H bond halogenation with lithium halides under aerobic conditions
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A concise and practical Cu-catalyzed protocol for the preparation of chloro- and bromoarenes via C-H bond activation has been developed. The advantages of this strategy are the employment of cheap Cu(NO3) 2·3H2O, LiX and O2, and its compatibility with both electron-donating and electron-withdrawing substituents on aryl rings.
- Mo, Song,Zhu, Yamin,Shen, Zengming
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supporting information
p. 2756 - 2760
(2013/05/08)
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- Synthetic control over photoinduced electron transfer in phosphorescence zinc sensors
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Despite the promising photofunctionalities, phosphorescent probes have been examined only to a limited extent, and the molecular features that provide convenient handles for controlling the phosphorescence response have yet to be identified. We synthesized a series of phosphorescence zinc sensors based on a cyclometalated heteroleptic Ir(III) complex. The sensor construct includes two anionic cyclometalating ligands and a neutral diimine ligand that tethers a di(2-picolyl)amine (DPA) zinc receptor. A series of cyclometalating ligands with a range of electron densities and band gap energies were used to create phosphorescence sensors. The sensor series was characterized by variable-temperature steady-state and transient photoluminescence spectroscopy studies, electrochemical measurements, and quantum chemical calculations based on time-dependent density functional theory. The studies demonstrated that the suppression of nonradiative photoinduced electron transfer (PeT) from DPA to the photoexcited IrIV species provided the underlying mechanism that governed the phosphorescent response to zinc ions. Importantly, the Coulombic barrier, which was located on either the cyclometalating ligand or the diimine ligand, negligibly influenced the PeT process. Phosphorescence modulation by PeT strictly obeyed the Rehm-Weller principle, and the process occurred in the Marcus-normal region. These findings provide important guidelines for improving sensing performance; an efficient phosphorescence sensor should include a cyclometalating ligand with a wide band gap energy and a deep oxidation potential. Finally, the actions of the sensor were demonstrated by visualizing the intracellular zinc ion distribution in HeLa cells using a confocal laser scanning microscope and a photoluminescence lifetime imaging microscope.
- Woo, Hana,Cho, Somin,Han, Yejee,Chae, Weon-Sik,Ahn, Dae-Ro,You, Youngmin,Nam, Wonwoo
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p. 4771 - 4787
(2013/06/04)
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- Pd(II)-catalyzed phosphorylation of aryl C-H bonds
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A Pd(II)-catalyzed C-H phosphorylation reaction has been developed using heterocycle-directed ortho-palladation. Both H-phosphonates and diaryl phosphine oxides are suitable coupling partners for this reaction.
- Feng, Chen-Guo,Ye, Mengchun,Xiao, Kai-Jiong,Li, Suhua,Yu, Jin-Quan
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supporting information
p. 9322 - 9325
(2013/07/19)
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- Pyridine-directed palladium-catalyzed phosphonation of C(sp2)-H bonds
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Follow the guide: The palladium-catalyzed phosphonation of a C(sp 2)-H bond occurs through the use of a pyridyl group as the directing group. α-Hydroxyalkylphosphonate is used as the phosphonating reagent (see scheme). Copyright
- Li, Changkun,Yano, Takaaki,Ishida, Naoki,Murakami, Masahiro
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supporting information
p. 9801 - 9804
(2013/09/23)
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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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- NOVEL TETRADENTATE PLATINUM COMPLEXES
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Novel phosphorescent tetradentate platinum (II) compounds comprising a twisted aryl group are provided. Also provided are novel phosphorescent tetradentate platinum (II) compounds comprising an imidazo[1,2-f]phenanthridine moiety. The compounds may be used in organic light emitting devices to provide improved device efficiency, line shape and lifetime.
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Page/Page column 131-132
(2012/09/11)
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- Rhodium-catalyzed intermolecular amidation of arenes with sulfonyl azides via chelation-assisted C-H bond activation
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We report the direct amidation of arene C-H bonds using sulfonyl azides as the amino source to release N2 as the single byproduct. The reaction is catalyzed by a cationic rhodium complex under external oxidant-free conditions in the atmospheric environment. A broad range of chelate group-containing arenes are selectively amidated with excellent functional group tolerance, thus opening a new avenue to practical intermolecular C-N bond formation.
- Kim, Ji Young,Park, Sae Hume,Ryu, Jaeyune,Cho, Seung Hwan,Kim, Seok Hwan,Chang, Sukbok
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supporting information; experimental part
p. 9110 - 9113
(2012/07/14)
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