- Iridium(III) complexes with phenyl-tetrazoles as cyclometalating ligands
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Ir(III) cationic complexes with cyclometalating tetrazolate ligands were prepared for the first time, following a two-step strategy based on (i) a silver-assisted cyclometalation reaction of a tetrazole derivative with IrCl3 affording a bis-cyclometalated solvato-complex P ([Ir(ptrz)2(CH3CN)2]+, Hptrz = 2-methyl-5-phenyl-2H-tetrazole); (ii) a substitution reaction with five neutral ancillary ligands to get [Ir(ptrz)2L]+, with L = 2,2′-bypiridine (1), 4,4′-di-tert-butyl-2,2′-bipyridine (2), 1,10-phenanthroline (3), and 2-(1-phenyl-1H-1,2,3-triazol-4-yl)pyridine (4), and [Ir(ptrz)2L2]+, with L = tert-butyl isocyanide (5). X-ray crystal structures of P, 2, and 3 were solved. Electrochemical and photophysical studies, along with density functional theory calculations, allowed a comprehensive rationalization of the electronic properties of 1-5. In acetonitrile at 298 K, complexes equipped with bipyridine or phenanthroline ancillary ligands (1-3) exhibit intense and structureless emission bands centered at around 540 nm, with metal-to-ligand and ligand-to-ligand charge transfer (MLCT/LLCT) character; their photoluminescence quantum yields (PLQYs) are in the range of 55-70%. By contrast, the luminescence band of 5 is weak, structured, and blue-shifted and is attributed to a ligand-centered (LC) triplet state of the tetrazolate cyclometalated ligand. The PLQY of 4 is extremely low (a nonemissive triplet metal-centered ( 3MC) state. In rigid matrix at 77 K, all of the complexes exhibit intense luminescence. Ligands 1-3 are also strong emitters in solid matrices at room temperature (1% poly(methyl methacrylate) matrix and neat films), with PLQYs in the range of 27-70%. Good quality films of 2 could be obtained to make light-emitting electrochemical cells that emit bright green light and exhibit a maximum luminance of 310 cd m-2. Tetrazolate cyclometalated ligands push the emission of Ir(III) complexes to the blue, when compared to pyrazolate or triazolate analogues. More generally, among the cationic Ir(III) complexes without fluorine substituents on the cyclometalated ligands, 1-3 exhibit the highest-energy MLCT/LLCT emission bands ever reported.
- Monti, Filippo,Baschieri, Andrea,Gualandi, Isacco,Serrano-Perez, Juan J.,Junquera-Hernandez, Jose M.,Tonelli, Domenica,Mazzanti, Andrea,Muzzioli, Sara,Stagni, Stefano,Roldan-Carmona, Cristina,Pertegas, Antonio,Bolink, Henk J.,Orti, Enrique,Sambri, Letizia,Armaroli, Nicola
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- Alkylation of 5-Substituted 1 H-Tetrazoles via the Diazotization of Aliphatic Amines
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A new alkylation reaction of monosubstituted tetrazoles via the diazotization of aliphatic amines is reported. This method enables preferential formation of 2,5-disubstituted tetrazoles. A one-pot 1,3-dipolar cycloaddition/diazotization sequence starting from widely available nitriles is also described. Azide residues are quenched in the second step with the nitrite reagent, thus limiting the intrinsic risk associated with trimethylsilyl azide. The reaction conditions were compatible with several functional groups, including thiocyanates, which afford preferentially disubstituted 2-alkyl-5-(substituted-thio)tetrazoles.
- Lebel, Hélène,Reynard, Guillaume
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p. 12452 - 12459
(2021/09/07)
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- Bu4NI-Catalyzed, Radical-Induced Regioselective N-Alkylations and Arylations of Tetrazoles Using Organic Peroxides/Peresters
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Bu4NI-catalyzed regioselective N2-methylation, N2-Alkylation, and N2-Arylation of tetrazoles have been achieved using tert-butyl hydroperoxide (TBHP) as the methyl source, alkyl diacyl peroxides as the primary alkyl source, alkyl peresters as the secondary and tertiary alkyl sources, and aryl diacyl peroxides as the arylating source. These reactions proceed without pre-functionalization of tetrazole and in the absence of any metal catalysts. Here, peroxides serve the dual role of oxidants as well as alkylating or arylating agents. Based on DFT calculations, it was found that spin density, transition-state barriers (kinetic control), and thermodynamic stability of the products (thermodynamic control) play essential roles in the observed regioselectivity during N-Alkylation. This radical-mediated process is amenable to a broad range of substrates and provides products in moderate to good yields.
- Ghosh, Subhendu,Mir, Bilal Ahmad,Patel, Bhisma K.,Rajamanickam, Suresh,Sah, Chitranjan,Sethi, Garima,Venkataramani, Sugumar,Yadav, Vinita
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p. 2118 - 2141
(2020/03/13)
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- Ruthenium-Catalyzed meta-Selective C?H Nitration of Biologically Important Aryltetrazoles
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The first example of tetrazole-directed meta-selective C?H nitration is described. This transformation provided a straightforward approach for the synthesis of biologically important m-nitroaryltetrazoles in moderate to excellent yields with good functional group compatibility. In addition, new metallo-β-lactamase inhibitors were obtained by further transformation of the synthesized m-nitroaryltetrazoles. (Figure presented.).
- Chen, Jian,Huang, Tianle,Gong, Xinrui,Yu, Zhu-Jun,Shi, Yuesen,Yan, Yu-Hang,Zheng, Yang,Liu, Xuexin,Li, Guo-Bo,Wu, Yong
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p. 2984 - 2989
(2020/06/08)
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- Discovery of mercaptopropanamide-substituted aryl tetrazoles as new broad-spectrum metallo-β-lactamase inhibitors
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β-Lactam antibiotic resistance mediated by metallo-β-lactamases (MBL) has threatened global public health. There are currently no available inhibitors of MBLs for clinical use. We previously reported the ruthenium-catalyzed meta-selective C-H nitration synthesis method, leading to some meta-mercaptopropanamide substituted aryl tetrazoles as new potent MBL inhibitors. Here, we described the structure-activity relationship of meta- and ortho-mercaptopropanamide substituted aryl tetrazoles with clinically relevant MBLs. The resulting most potent compound 13a showed IC50 values of 0.044 μM, 0.396 μM and 0.71 μM against VIM-2, NDM-1 and IMP-1 MBL, respectively. Crystallographic analysis revealed that 13a chelated to active site zinc ions via the thiol group and interacted with the catalytically important residues Asn233 and Tyr67, providing further structural information for the development of thiol based MBL inhibitors. This journal is
- Yan, Yu-Hang,Chen, Jian,Zhan, Zhen,Yu, Zhu-Jun,Li, Gen,Guo, Li,Li, Guo-Bo,Wu, Yong,Zheng, Yongxiang
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p. 31377 - 31384
(2020/09/21)
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- ACLY INHIBITORS AND USES THEREOF
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The present invention provides compounds useful as inhibitors of ATP citrate lyase (ACLY), compositions thereof, and methods of using the same.
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Paragraph 00409
(2020/06/01)
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- Preparation of 5-Aryl-2-Alkyltetrazoles with Aromatic Aldehydes, Alkylhydrazine, Di-tert-butyl Azodicarboxylate, and [Bis(trifluoroacetoxy)iodo]benzene
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A variety of 5-aryl-2-methyltetrazoles and 5-aryl-2-benzyltetrazoles were directly prepared in good to moderate yields by the reaction of aromatic aldehydes with methylhydrazine and benzylhydrazine, followed by treatment with di-tert-butyl azodicarboxylate and [bis(trifluoroacetoxy)iodo]benzene in a mixture of dichloromethane and 2,2,2-trifluoroethanol at room temperature. The present method is a novel one-pot preparation of 5-aryl-2-methyltetrazoles and 5-aryl-2-benzyltetrazoles through a [2N + 2N] combination under transition metal-free and mild conditions.
- Imai, Taro,Harigae, Ryo,Moriyama, Katsuhiko,Togo, Hideo
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p. 3975 - 3980
(2016/05/24)
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- Alkylation of 5-substituted NH-tetrazoles by alcohols in the superacid CF3SO3H
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Reactions of 5-substituted NH-tetrazoles with alcohols in the superacid CF3SO3H have been studied. Both the structure of the tetrazole and the nature of alcohol were found to dramatically influence the selectivity of the reaction and yields of products. Tetrazoles bearing phenyl, electron-donating aryl, or benzyl groups at the 5-position, have been alkylated using various alcohols (including MeOH and EtOH) in CF3SO3H upon heating at 60 °C for 0.3-12 h to afford 2-alkyl-2H-tetrazoles in 30-98% yields.
- Lisakova, Anna D.,Ryabukhin, Dmitry S.,Trifonov, Rostislav E.,Ostrovskii, Vladimir A.,Vasilyev, Aleksander V.
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supporting information
p. 7020 - 7023
(2015/11/27)
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- An Environmentally Friendly Method for N-Methylation of 5-Substituted 1H-Tetrazoles with a Green Methylating Reagent: Dimethyl Carbonate
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An environmentally friendly method was established for the N-methylation of the 5-substituted 1H-tetrazoles with a green reagent: DMC. DABCO was the optimal catalyst, and hazardous chemicals were avoided in this protocol. A plausible catalytic mechanism is proposed, which consists of a DABCO-activated process and a thermally induced rearrangement of tetrazole carbamates.
- Xie, Aming,Zhang, Qiang,Liu, Yangyang,Feng, Liandong,Hu, Xinyu,Dong, Wei
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p. 1483 - 1487
(2015/10/06)
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- Rhodium-catalyzed olefination of aryl tetrazoles via direct C-H bond activation
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Rh(III)-catalyzed direct olefination reaction via aromatic C-H bond activation is described using tetrazole as the directing group. This reaction provides a straightforward way for the synthesis of ortho-alkenyl aryl tetrazoles. Various functional groups tolerate the reaction conditions and afford the corresponding products in moderate to excellent yields.
- Wang, Liang,Wu, Wenting,Chen, Qun,He, Mingyang
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p. 7923 - 7926
(2015/01/09)
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- The reaction of 2-((trimethylsilyl)methyl)-2htetrazoles with aldehydes and ketones in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene
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2-((Trimethylsilyl)methyl)-2H-tetrazoles were treated with aldehydes and ketones in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) to give 2-(2-hydroxyethyl)-2H-tetrazoles. This simple procedure offers a valuable strategy for the preparation of 2-(hydroxyethyl)-2H-tetrazoles.
- Umemoto, Hideaki,Onaka, Takuya,Miki, Yasuyoshi,Nakamura, Akira,Maegawa, Tomohiro
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p. 2545 - 2553
(2015/01/09)
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- Continuous flow generation and reactions of anhydrous diazomethane using a teflon AF-2400 tube-in-tube reactor
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A continuous process for generation, separation, and reactions of anhydrous diazomethane in a tube-in-tube reactor was developed. The inner tube of the reactor is made of hydrophobic, gas-permeable Teflon AF-2400. The diazomethane is formed in the inner tube and then diffuses through the permeable membrane into the outer chamber and subsequently reacts in the solution carried within. This technique allows safe and scalable reactions with dry diazomethane to be performed on a laboratory scale.
- Mastronardi, Federica,Gutmann, Bernhard,Oliver Kappe
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supporting information
p. 5590 - 5593
(2013/11/19)
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- Tetrazoles: LIV. Alkylation of 5-aryltetrazoles under microwave activation
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The application of microwave activation (MWA) to alkylation of 5-aryltetrazoles with dimethyl sulfate in organic solvents did not considerably affect the selectivity of the process compared to nonactivated procedure. A significant enhancement of the selec
- Efimova,Artamonova,Koldobskii
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experimental part
p. 725 - 727
(2009/10/11)
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- TETRAZOLES. XVI. ALKYLATION OF TETRAZOLES UNDER THE CONDITIONS OF PHASE-TRANSFER CATALYSIS
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The alkylation of tetrazole and 5-substituted tetrazoles with dimethyl sulfate and methyl iodide in the two-phase methylene chloride-water system in the presence of tetrabutylammonium bromide was investigated.The alkylation of tetrazoles with methyl iodide takes place in the organic phase, while that with dimethyl sulfate takes place both in the organic and in the aqueous phases.The ratio of the isomeric tetrazoles formed during the alkylation of 5-aryltetrazoles by methyl iodide correlate with the substituent constants ?.The use of phase-transfer catalysis during the alkylation of tetrazoles does not lead to a change in the selectivity of the reaction.
- Osipova, T. F.,Ostrovskii, V. A.,Koldobskii, G. I.,Erusalimskii, G. B.
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p. 357 - 362
(2007/10/02)
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- TETRAZOLES. XII. EFFECT OF SPECIFIC SOLVATION ON THE RATE AND SELECTIVITY OF ALKYLATION OF 5-PHENYLTETRAZOLE SALTS BY DIMETHYLSULFATE
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The kinetics of the alkylation of 5-phenyltetrazole potassium salt by dimethysulfate in a mixed acetonitrile-water solvent containing up to 7.6 wt.percent of water were investigated.As the water content of the solvent increases, the alkylation rate decreases and the proportion of 2-methyl-5-phenyl tetrazole in the reaction products increases.During the alkylation of 5-phenyltetrazole lithium, potassium, and cesium salts in aqueous acetonitrile the ratio of the isomeric reaction products does not depend on the nature of the cation which forms the salt.
- Agarkova, L.N.,Ostrovskii, V.A.,Koldobskii, G.I.,Erusalimskii, G.B.
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p. 903 - 906
(2007/10/02)
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- TETRAZOLES. VIII. KINETICS AND RATIO OF THE REACTION PRODUCTS IN THE ALKYLATION OF THE SALTS OF SUBSTITUTED 5-PHENYLTETRAZOLES BY DIMETHYL SULFATE IN ACETONITRILE
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The kinetics and the ratio of the reaction products were investigated for the alkylation of potassium salts of a series of substituted 5-phenyltetrazoles by dimethyl sulfate in acetonitrile.It was shown that with the salt at a concentration of less than 10-3M the corresponding tetrazolate ion enters into reaction with dimethyl sulfate.Electron-withdrawing substituents in the benzene ring reduce the rate of the alkylation reaction and help to increase the proportion of the N2 isomer in the reaction products.The rate constants for the reaction of substituted 5-phenyltetrazoles with dimethyl sulfate and the ratios of the isomeric tetrazoles formed during alkylation correlate with the ? constants of the substituents.
- Ostrovskii, V. A.,Shirobokov, I. Yu.,Koldobskii, G. I.
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p. 131 - 135
(2007/10/02)
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- TETRAZOLES. VI. EFFECT OF THE NATURE OF THE CATION ON THE KINETICS AND RATIO OF THE REACTION PRODUCTS IN THE ALKYLATION OF 9-PHENYLTETRAZOLE SALTS BY DIMETHYL SULFATE IN ACETONITRILE
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It was shown that the sodium, potassium, cesium, and tetrametylammonium salts of 5-phenyltetrazole in acetonitrile are fully dissociated at concentrations of less than 1E-3.During alkylation of the above-mentioned salts with dimethyl sulfate in acetonitrile the reactive particle is 5-phenyltetrazole anion.It was found that ratio of the alkylation products depends on the nature of the cation.The obtained data agree well with a two-stage mechanism for the alkylation of 5-substituted tetrazoles.
- Shirobokov, I. Yu.,Ostrovskii, V. A.,Koldobskii, G. I.
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p. 691 - 695
(2007/10/02)
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