- Regioselective nitration of a biphenyl derivative to derive a fluorescent chloride sensor
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Methyl 2′-aminobiphenyl-4-carboxylate, an optical chloride sensor has been synthesized via Suzuki-Miyaura cross-coupling followed by regioselective nitration. In general biphenyl systems are prone to undergo poly nitration whenever they are subjected to nitration via different nitrating agents. But in this present work, a highly selective nitration in the 2′ position of methyl biphenyl-4-carboxylate was achieved using 70% HNO3 and acetic anhydride to derive 3. Upon reduction, 3 produces 4 which shows bright blue emission in different organic solvents. In presence of chloride ion the blue emission of the sensor changes to enhanced bright green emission. The chloride sensing has also been explored using other spectroscopic techniques such as 1H NMR, UV–vis spectroscopy, and theoretical study.
- Das, Tanmay,Mohar, Mrittika,Bag, Arijit
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- α-Bromoacrylic Acids as C1 Insertion Units for Palladium-Catalyzed Decarboxylative Synthesis of Diverse Dibenzofulvenes
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Herein α-bromoacrylic acids have been employed as C1 insertion units to achieve the palladium-catalyzed [4 + 1] annulation of 2-iodobiphenyls, which provides an efficient platform for the construction of diverse dibenzofulvenes. This protocol enables the formation of double C(aryl)-C(vinyl) bonds via a C(vinyl)-Br bond cleavage and decarboxylation. It is particularly noteworthy that the method features a broad substrate scope, and various interesting frameworks, such as bridged ring, fused (hetero)aromatic ring, and divinylbenzene, can be successfully incorporated into the products.
- Zhang, Minghao,Deng, Wenbo,Sun, Mingjie,Zhou, Liwei,Deng, Guobo,Liang, Yun,Yang, Yuan
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supporting information
p. 5744 - 5749
(2021/08/18)
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- Atmosphere-Controlled Palladium-Catalyzed Divergent Decarboxylative Cyclization of 2-Iodobiphenyls and α-Oxocarboxylic Acids
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A novel palladium-catalyzed divergent decarboxylative cyclization of 2-iodobiphenyls and α-oxocarboxylic acids utilizing the atmosphere as a controlled switch is reported. Under the protection of a nitrogen atmosphere, tribenzotropones are synthesized by a [4 + 3] decarboxylative cyclization. Employing a palladium/O2 system enables a [4 + 2] decarboxylative cyclization to assemble triphenylenes. Notably, preliminary mechanistic studies indicate that the formation of triphenylenes involves a double decarboxylation.
- Zhou, Liwei,Sun, Mingjie,Zhou, Fengru,Deng, Guobo,Yang, Yuan,Liang, Yun
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supporting information
p. 7150 - 7155
(2021/09/18)
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- Palladium-Catalyzed C-H Amination/[2 + 3] or [2 + 4] Cyclization via C(sp3or sp2)-H Activation
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This report describes a palladium-catalyzed Catellani reaction consisting of amination/[2 + 3] or [2 + 4] cyclization via a carboxylate ligand-exchange strategy. This method effectively activates ortho-substituents that avoid a second C-H palladation. The scope of substrates was broad, o-methyl-substituted iodoarenes were applied to the reaction smoothly, and o-phenyl-substituted iodoarenes can also be obtained by this method. In terms of mechanism, density functional theory calculations proved the sequence of the key five-membered aryl-norbornene-palladacycle intermediate formation and C(sp3 or sp2)-H activation.
- An, Yang,Ding, Ya-Nan,Gou, Xue-Ya,Li, Qiao,Li, Yuke,Liang, Yong-Min,Zhang, Xiao-Yan,Zhang, Zhe
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supporting information
p. 7961 - 7965
(2021/10/25)
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- Photocatalytic xanthate-based radical addition/cyclization reaction sequence toward 2-biphenyl isocyanides: Synthesis of 6-alkylated phenanthridines
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A photocatalytic xanthate-based radical addition/cyclization reaction cascade toward 2-biphenylisocyanides is described as a practical and modular approach to 6-alkylated phenanthridines. The use of xanthates as radical precursors allowed the synthesis of diversely 6-substituted phenanthridines. Electrophilic radicals derived from nitriles, aromatic and aliphatic ketones, malonates, and amide derivatives, as well as radicals derived from phthalimidomethyl and benzylic derivatives were successfully introduced. The reaction proceeds under mild conditions without a stoichiometric amount of oxidant. Thirty novel phenanthridine scaffolds were synthesized with yields ranging from 24 to 76%.
- López-Mendoza, Pedro,Miranda, Luis D.
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supporting information
p. 3487 - 3491
(2020/05/25)
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- Design, synthesis, and evaluation of N-phenyl-4-(2-phenylsulfonamido)-benzamides as microtubule-targeting agents in drug-resistant cancer cells, displaying HDAC inhibitory response
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Microtubule-targeting agents (MTA) have enjoyed significant clinical success for decades. However, several mechanisms may cause inactivation of such drugs, leading to acquired resistance in patients treated with them. Therefore, drugs containing a stilbene-like skeleton and possessing dual inhibitory activity may provide a new and differentiated treatment for patients to overcome challenging acquired resistance. A new compound (16c) displays promising anticancer activity with GI50 of 22 ± 2 and 12 ± 0.1 nM in vincristine-resistant nasopharyngeal (KB-Vin) cancer cells and etoposide-resistant nasopharyngeal (KB-7D) cancer cells and is better than vincristine, etoposide, ABT-751, and MS-275. A mechanistic study revealed that 16c interferes with the cell cycle distribution and induces cell cycle arrest at the G2/M phase and severe mitotic spindle defects followed by apoptosis. In addition, it produces much more significant cytotoxicity than vincristine and etoposide in the corresponding resistant cells, indicating that it may be a promising candidate to overcome drug resistance in cancer cells. Compound 16c also displays inhibitory activity against HDAC 1 and HDAC 2 with IC50 values of 1.07 μM, and 1.47 μM, respectively. These findings may lead to a new type of structural motif for future development of drugs that could overcome acquired resistance to MTAs.
- Chen, Chun-Han,Chuang, Hsun-Yueh,Hung, To-Yu,Lai, Mei-Jung,Liao, Yu-Hsuan,Lin, Mei-Hsiang,Liou, Jing-Ping,Liu, Yi-Min,Wu, Wei-Cheng
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- Palladium/Norbornene Chemistry: Synthesis of Norbornene-Containing Arylsilanes Involving Double C-Si Bond Formation
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A novel palladium-catalyzed three-component cascade reaction of aryl halides with norbornene and hexamethyldisilane has been described, which allows the simultaneous construction of two C-Si bonds and one C-C bond. The method achieves ortho C-H functionalization of aryl halides through the formation of the five-membered palladacycle, leading to norbornene-containing arylsilanes.
- Xu, Yankun,Liu, Xiaodong,Chen, Wenqi,Deng, Guobo,Liang, Yun,Yang, Yuan
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p. 13930 - 13939
(2018/11/30)
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- Visible Light-Induced Radical Cyclization of Tertiary Bromides with Isonitriles to Construct Trifluoromethylated Quaternary Carbon Center
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The reaction of trifluoromethylated tertiary bromides with isonitriles induced by visible light is reported. Defluorination was avoided in a radical process. This method provides an efficient approach to compounds containing a trifluoromethylated quaternary carbon center, most of which show excellent potential to be agrochemicals. In addition, the bromides were prepared from perfluoroisobutylene, which is a waste from industry, after several steps. This reaction shows a feasible transfer of harmful waste into useful compounds.
- Wang, Wengui,Guo, Yong,Sun, Ke,Wang, Shoufeng,Zhang, Shuxiang,Liu, Chao,Chen, Qing-Yun
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p. 14588 - 14599
(2018/12/11)
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- Visible-light-promoted intramolecular C-H amination in aqueous solution: Synthesis of carbazoles
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An effective and operationally simple protocol is reported for the synthesis of versatile carbazoles. With water as a co-solvent, visible-light rather than various metals is used to facilitate the conversion of readily available 2-azidobiphenyls under mild conditions. Various functionalized bioactive natural alkaloids, such as glycoborine, clausine C, clausine L, clausine H and clauszoline K, were synthesized efficiently with nitrogen as a sole byproduct. The reaction could be performed in water, acidic or alkaline buffer solutions, showing its potential for applications in biochemistry.
- Yang, Lizheng,Zhang, Yipin,Zou, Xiaodong,Lu, Hongjian,Li, Guigen
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supporting information
p. 1362 - 1366
(2018/03/26)
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- Photochemical intramolecular amination for the synthesis of heterocycles
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Polycyclic heterocycles can be formed in good to excellent yields via photochemical conversion of the corresponding substituted aryl azides under irradiation with purple LEDs in a continuous flow reactor. The experimental set-up is tolerant to UV-sensitive functional groups while affording diverse carbazoles, as well as an indole and pyrrole framework, in short reaction times. The photochemical method is presumed to progress through a mechanism differing from the other methods of azide activation involving transition metal catalysis.
- Parisien-Collette, Shawn,Cruché, Corentin,Abel-Snape, Xavier,Collins, Shawn K.
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supporting information
p. 4798 - 4803
(2017/10/23)
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- Radical (Phenylsulfonyl)difluoromethylation of Isocyanides with PhSO2CF2H under Transition-Metal-Free Conditions
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An atom-economical method for radical (phenylsulfonyl)difluoromethylation of isocyanides with PhSO2CF2H under transition-metal-free conditions has been developed. A PhSO2CF2 radical is generated through the oxidation of PhSO2CF2- after the deprotonation of PhSO2CF2H in one pot. The reaction exhibits excellent functional-group tolerance and the resulting products can be further modified with the removal of a PhSO2 group to give other CF2-containing compounds.
- Xiao, Pan,Rong, Jian,Ni, Chuanfa,Guo, Junkai,Li, Xinjin,Chen, Dingben,Hu, Jinbo
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supporting information
p. 5912 - 5915
(2016/11/29)
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- Synthesis of Fluorenes Starting from 2-Iodobiphenyls and CH2Br2 through Palladium-Catalyzed Dual C-C Bond Formation
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A facile and efficient approach is developed for the synthesis of fluorene and its derivatives starting from 2-iodobiphenyls and CH2Br2. A range of fluorene derivatives can be synthesized under relatively mild conditions. The reaction proceeds via a tandem palladium-catalyzed dual C-C bond formation sequence through the key dibenzopalladacyclopentadiene intermediates, which are obtained from 2-iodobiphenyls through palladium-catalyzed C-H activation.
- Shi, Guangfa,Chen, Dushen,Jiang, Hang,Zhang, Yu,Zhang, Yanghui
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supporting information
p. 2958 - 2961
(2016/07/06)
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- Synthesis of Triphenylenes Starting from 2-Iodobiphenyls and Iodobenzenes via Palladium-Catalyzed Dual C-H Activation and Double C-C Bond Formation
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A novel and facile approach for the synthesis of triphenylenes has been developed via palladium-catalyzed coupling of 2-iodobiphenyls and iodobenzenes. The reaction involves dual palladium-catalyzed C-H activations and double palladium-catalyzed C-C bond formations. A range of unsymmetrically functionalized triphenylenes can be synthesized with the reaction. The approach features readily available starting materials, high atom- and step-economy, and access to various unsymmetrically functionalized triphenylenes.
- Zhang, Yanghui,Pan, Shulei,Jiang, Hang,Zhang, Yu,Chen, Dushen
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supporting information
p. 5192 - 5195
(2016/11/02)
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- Palladium-Catalyzed Intramolecular C–H Amination in Water
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Palladium(II) catalysis was found to be effective for intramolecular C–H amination in water. With 2-azidobiphenyls as substrates, the reaction efficiently provided various carbazoles with N2as the sole byproduct. The reaction showed high functional-group tolerance and could be used in the synthesis of several natural carbazole alkaloids. The catalytic process was promoted by water, and the reaction was inefficient in the organic solvents that were investigated.
- Yang, Lizheng,Li, Hao,Zhang, Haifei,Lu, Hongjian
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supporting information
p. 5611 - 5615
(2016/12/14)
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- N-Sulfonyl-aminobiaryls as Antitubulin Agents and Inhibitors of Signal Transducers and Activators of Transcription 3 (STAT3) Signaling
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A series of N-sulfonyl-aminobiaryl derivatives have been examined as novel antitubulin agents. Compound 21 [N-(4′-cyano-3′-fluoro-biphenyl-2-yl)-4-methoxy-benzenesulfonamide] exhibits remarkable antiproliferative activity against four cancer cell lines (pancreatic AsPC-1, lung A549, liver Hep3B, and prostate PC-3) with a mean GI50 value of 57.5 nM. Additional assays reveal that 21 inhibits not only tubulin polymerization but also the phosphorylation of STAT3 inhibition with an IC50 value of 0.2 μM. Four additional compounds (8, 10, 19, and 35) are also able to inhibit this phosphorylation. This study describes novel N-sulfonyl-aminobiaryl (biaryl-benzenesulfonamides) as potent anticancer agents targeting both STAT3 and tubulin. (Chemical Equation Presented).
- Lai, Mei-Jung,Lee, Hsueh-Yun,Chuang, Hsun-Yueh,Chang, Li-Hsun,Tsai, An-Chi,Chen, Mei-Chuan,Huang, Han-Lin,Wu, Yi-Wen,Teng, Che-Ming,Pan, Shiow-Lin,Liu, Yi-Min,Mehndiratta, Samir,Liou, Jing-Ping
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p. 6549 - 6558
(2015/09/07)
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- Direct synthesis of N -H carbazoles via iridium(III)-catalyzed intramolecular C-H amination
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The iridium-catalyzed dehydrogenative cyclization of 2-aminobiphenyls proceeds smoothly in the presence of a copper cocatalyst under air as a terminal oxidant through intramolecular direct C-H amination to produce N-H carbazoles. A similar iridium/copper system can also catalyze the unprecedented dimerization reaction of 2-aminobiphenyl involving 2-fold C-H/N-H couplings.
- Suzuki, Chiharu,Hirano, Koji,Satoh, Tetsuya,Miura, Masahiro
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supporting information
p. 1597 - 1600
(2015/03/30)
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- Synthesis of carbazoles by copper-catalyzed intramolecular C-H/N-H coupling
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A Cu-catalyzed intramolecular C-H amination for the synthesis of carbazoles has been developed. The key to success is the installation of the picolinamide-based directing group, which is spontaneously removed after the coupling event. The Cu catalysis proceeded smoothly under Pd- and I(III)-free conditions, and its mild oxidation aptitude enables the rapid and concise construction of heteroatom-incorporated carbazole core π-systems.
- Takamatsu, Kazutaka,Hirano, Koji,Satoh, Tetsuya,Miura, Masahiro
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supporting information
p. 2892 - 2895
(2014/06/23)
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- PhI(OAc)2-mediated synthesis of 6-(trifluoromethyl) phenanthridines by oxidative cyclization of 2-isocyanobiphenyls with CF 3SiMe3 under metal-free conditions
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A mild and efficient method for the synthesis of 6-(trifluoromethyl) phenanthridines through oxidative cyclization of 2-isocyanobiphenyls with CF3SiMe3 under metal-free conditions was developed. The reaction allows the direct formation of C-CF3 bonds and rapid access to phenanthridine ring systems in one catalytic cycle.
- Wang, Qile,Dong, Xichang,Xiao, Tiebo,Zhou, Lei
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supporting information
p. 4846 - 4849
(2013/10/08)
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- ORNITHINE DERIVATIVES AS PROSTAGLANDIN E2 AGONISTS OR ANTAGONISTS
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Ornithine derivatives of the formula (I): wherein X is -CO- or -(CH2) k- (wherein k is 1, 2 or 3); Y is Z-(CH2) n-, and the like; {wherein Z is R1-CO-NR4-, and the like, (wherein R1 is aryl, and the like; and R4 is hydrogen, or lower alkyl); and n is 1, 2, 3, 4, 5 or 6}; R2 is aryl-(lower alkyl), and the like; R3 is -Q-R7, [wherein Q is -CO- or -SO2-, R7 is heterocyclyl], and the like; and R5 and R6 are independently hydrogen or lower alkyl; or a pharmaceutically acceptable salt thereof, which are useful as medicament.
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(2010/02/12)
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