- Highly Efficient and Catalyst-Free Synthesis of Benzimidazoles in Aqueous Media
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Abstract: A convenient and highly efficient, catalysts-free synthesis of benzimidazoles in an aqueous medium has been developed. The conditions of the synthesis were optimized, and its scope was successfully extended to various substrates with good to excellent yields. The experimental procedure is simple, and the products can be isolated by filtration followed by recrystallization from water.
- Huang, W.-H.,Jin, Y.-J.,Ma, L.-F.,Wu, Y.,Zhou, L.-H.
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p. 825 - 830
(2021/06/12)
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- Impact of 3-deazapurine nucleobases on RNA properties
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Deazapurine nucleosides such as 3-deazaadenosine (c3A) are crucial for atomic mutagenesis studies of functional RNAs. They were the key for our current mechanistic understanding of ribosomal peptide bond formation and of phosphodiester cleavage in recentl
- Bereiter, Raphael,Himmelsto?, Maximilian,Renard, Eva,Mairhofer, Elisabeth,Egger, Michaela,Breuker, Kathrin,Kreutz, Christoph,Ennifar, Eric,Micura, Ronald
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p. 4281 - 4293
(2021/06/01)
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- In Situ Formation of Frustrated Lewis Pairs in a Water-Tolerant Metal-Organic Framework for the Transformation of CO2
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Frustrated Lewis pairs (FLPs) consist of sterically hindered Lewis acids and Lewis bases, which provide high catalytic activity towards non-metal-mediated activation of “inert” small molecules, including CO2 among others. One critical issue of homogeneous FLPs, however, is their instability upon recycling, leading to catalytic deactivation. Herein, we provide a solution to this issue by incorporating a bulky Lewis acid-functionalized ligand into a water-tolerant metal-organic framework (MOF), named SION-105, and employing Lewis basic diamine substrates for the in situ formation of FLPs within the MOF. Using CO2 as a C1-feedstock, this combination allows for the efficient transformation of a variety of diamine substrates into benzimidazoles. SION-105 can be easily recycled by washing with MeOH and reused multiple times without losing its identity and catalytic activity, highlighting the advantage of the MOF approach in FLP chemistry.
- Shyshkanov, Serhii,Nguyen, Tu N.,Ebrahim, Fatmah Mish,Stylianou, Kyriakos C.,Dyson, Paul J.
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supporting information
p. 5371 - 5375
(2019/03/17)
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- Cobalt-catalyzed synthesis of N-containing heterocycles: Via cyclization of ortho -substituted anilines with CO2/H2
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The CO2-involved synthesis of chemicals is of great significance from the green and sustainable chemistry viewpoint. Herein, we report a non-noble metal catalytic system composed of CoF2, CsF and P(CH2CH2PPh2)3 (denoted as PP3) for the synthesis of N-containing heterocycles from ortho-substituted anilines and CO2/H2. Mechanism investigation indicates that [Co(PP3)H(CO2)]+ is a catalytically active intermediate under working conditions; and CsF plays important roles in activating ortho-substituted anilines via hydrogen bond interactions, thus promoting the formation of the final products. This catalytic system is highly efficient, and allows a wide scope of ortho-substituted anilines, together with excellent functional group tolerance, affording various N-containing heterocycles in good to excellent yields.
- Ke, Zhengang,Yu, Bo,Wang, Huan,Xiang, Junfeng,Han, Juanjuan,Wu, Yunyan,Liu, Zhenghui,Yang, Peng,Liu, Zhimin
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p. 1695 - 1701
(2019/04/10)
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- Synthesis of 1H-1,3-benzimidazoles, benzothiazoles and 3H-imidazo[4,5-c]pyridine using DMF in the presence of HMDS as a reagent under the transition-metal-free condition
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An operationally simple method for synthesis of benzimidazole and 3H-imidazo[4,5-c]pyridine from o-phenylenediamine or pyridine-3, 4-diamine and N,N-dimethylformamide (DMF) in the presence of hexamethyldisilazane (HMDS) as a reagent is described. To evaluate the scope of application of this reagent, it was also used to prepare benzothiazole, 1H-perimidine, and benzoxazole, which was successful for benzothiazole and 1H-perimidine but benzoxazole was not formed. This reaction complies with the principles of green chemistry as it does not use toxic solvents, transition metals, or strong acids. The products are obtained in moderate to excellent yields.
- Mostafavi, Hamid,Islami, Mohammad Reza,Ghonchepour, Ehsan,Tikdari, Ahmad Momeni
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p. 2973 - 2978
(2018/10/02)
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- Family-wide analysis of aminoacyl-sulfamoyl-3-deazaadenosine analogues as inhibitors of aminoacyl-tRNA synthetases
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Aminoacyl-tRNA synthetases (aaRSs) are enzymes that precisely attach an amino acid to its cognate tRNA. This process, which is essential for protein translation, is considered a viable target for the development of novel antimicrobial agents, provided species selective inhibitors can be identified. Aminoacyl-sulfamoyl adenosines (aaSAs) are potent orthologue specific aaRS inhibitors that demonstrate nanomolar affinities in vitro but have limited uptake. Following up on our previous work on substitution of the base moiety, we evaluated the effect of the N3-position of the adenine by synthesizing the corresponding 3-deazaadenosine analogues (aaS3DAs). A typical organism has 20 different aaRS, which can be split into two distinct structural classes. We therefore coupled six different amino acids, equally targeting the two enzyme classes, via the sulfamate bridge to 3-deazaadenosine. Upon evaluation of the inhibitory potency of the obtained analogues, a clear class bias was noticed, with loss of activity for the aaS3DA analogues targeting class II enzymes when compared to the equivalent aaSA. Evaluation of the available crystallographic structures point to the presence of a conserved water molecule which could have importance for base recognition within class II enzymes, a property that can be explored in future drug design efforts.
- Zhang, Baole,De Graef, Steff,Nautiyal, Manesh,Pang, Luping,Gadakh, Bharat,Froeyen, Matheus,Van Mellaert, Lieve,Strelkov, Sergei V.,Weeks, Stephen D.,Van Aerschot, Arthur
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p. 384 - 396
(2018/02/27)
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- Synthesis of benzimidazoles from o-phenylenediamines and DMF derivatives in the presence of PhSiH3
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A simple approach to preparation of benzimidazoles from o-phenylenediamines and DMF derivatives, only employing PhSiH3 as promoter without any other additives, was reported. This route provided moderate to high yields with a broad substrate scope. A plausible mechanism for the reaction is proposed based on the spectroscopic characterization (e.g., HRMS and 1H NMR) of the reaction mixture.
- Zhu, Jianhua,Zhang, Zhenbei,Miao, Chengxia,Liu, Wei,Sun, Wei
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p. 3458 - 3462
(2017/05/31)
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- CO2 as a C1 Source: B(C6F5)3-Catalyzed Cyclization of o-Phenylene-diamines To Construct Benzimidazoles in the Presence of Hydrosilane
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The catalytic construction of benzimidazoles using CO2 as a carbon source represents a facile and sustainable approach to obtaining these valuable compounds. Herein, we describe the B(C6F5)3-catalyzed synthesis of benzimidazoles via cyclization of o-phenylenediamines with CO2 and PhSiH3. This metal-free catalytic route achieves the desired products in high yield under convenient reaction conditions and is applicable to a broad substrate scope. A plausible mechanism for the reaction involving a frustrated Lewis pair pathway is proposed based on spectroscopic characterization (e.g., 13C NMR) of the reaction intermediates.
- Zhang, Zhenbei,Sun, Qiangsheng,Xia, Chungu,Sun, Wei
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supporting information
p. 6316 - 6319
(2016/12/23)
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- Atmospheric CO2 promoted synthesis of N-containing heterocycles over B(C6F5)3 catalyst
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B(C6F5)3 combined with atmospheric CO2 was found to be highly effective for the cyclization of ortho-substituted aniline derivatives with N,N-dimethylformamide (DMF), and a series of N-containing heterocycles including benzothiazoles, benzimidazoles, quinazolinone and benzoxazole were obtained in good to excellent yields.
- Gao, Xiang,Yu, Bo,Mei, Qingqing,Yang, Zhenzhen,Zhao, Yanfei,Zhang, Hongye,Hao, Leiduan,Liu, Zhimin
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p. 8282 - 8287
(2016/10/11)
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- Method For Preparing Nitrogen Compounds
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The present invention relates to a method for preparing nitrogen compounds using carbon dioxide, and to the use of the method in the production of vitamins, pharmaceutical products, adhesives, acrylic fibres, synthetic leathers, pesticides, herbicides, antifungal agents and fertilisers. The invention also relates to a method for producing vitamins, pharmaceutical products, adhesives, acrylic fibres, synthetic leathers, pesticides, herbicides, antifungal agents and fertilisers, which includes a step of preparing nitrogen compounds using the method of the invention. The invention further relates to a method for preparing labelled nitrogen compounds using carbon dioxide and to the uses thereof.
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Paragraph 0192; 0193
(2015/06/03)
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- Ultrasound promoted expeditious, catalyst-free and solvent-free approach for the synthesis of N,N′-diarylsubstituted formamidines at room temperature
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An effortless and efficient protocol was developed for the synthesis of N,N′-diarylsubstituted formamidines under environment-friendly conditions. Ultrasonic energy was employed to obtain the desired products in excellent yields with high purity under solvent-free and catalyst-free conditions. Products were purified by the crystallization technique to avoid excess utilization of organic solvents.
- Dar, Bashir Ahmad,Ahmad, Syed Naseer,Wagay, Mohammad Arif,Hussain, Altaf,Ahmad, Nisar,Bhat, Khursheed Ahmad,Khuroo, Mohammad Akbar,Sharma, Meena,Singh, Baldev
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p. 4880 - 4884
(2013/09/02)
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- Synthesis and Anti-herpetic Activity of Phosphoramidate ProTides
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Among the many prodrug approaches aimed at delivering nucleoside monophosphates into cells, the phosphoramidate ProTide approach is one that has shown success, which has made it possible for some of the phosphoramidates to enter into clinical trials. Herein, we report the synthesis and antiviral activity of a series of phosphoramidate ProTides designed to bypass the thymidine kinase (TK) dependence of the parent nucleoside analogues. Phosphoramidate derivatives of (E)-5-(2-bromovinyl)-2′-deoxyuridine (BVDU) that contain L-alanine or pivaloyloxymethyl iminodiacetate (IDA-POM) exhibit anti-HSV-1 and anti-VZV activity in cell cultures, but they largely lost antiviral potency against TK-deficient virus strains. Among deazapurine nucleosides and their phosphoramidate derivatives, the 7-deazaadenine containing nucleosides and their phosphoramidate triester derivatives showed weak antiviral activity against VZV. Apparently, intracellular nucleotide delivery with these phosphoramidates is partly successful. However, none of the compound prodrugs showed superior activity to their parent drugs. Copyright
- Maiti, Munmun,Persoons, Leentje,Andrei, Graciela,Snoeck, Robert,Balzarini, Jan,Herdewijn, Piet
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supporting information
p. 985 - 993
(2013/07/27)
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- A simple and convenient two-step, one-pot synthesis of hetero-imidazoles from nitroaminoaryls catalyzed by Ytterbium triflate
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A mild two-step one-pot procedure for the conversion of ortho-nitroamino aromatic heterocycles into corresponding benzo and heteroaromatic fused imidazoles is described. The procedure utilizes iron powder, acetic acid, triethylorthoformate, and a catalytic amount of Ytterbium triflate at 75 C for the nitro group reduction and cyclization reaction. The optimum stoichiometry of each component is highlighted and the broad utility is demonstrated with high compatibility to numerous functional groups.
- Wang, Fen,Tran-Dubé, Michelle,Scales, Stephanie,Johnson, Sarah,McAlpine, Indrawan,Ninkovic, Sacha
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p. 4054 - 4057
(2013/07/25)
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- Structural and vibrational properties of imidazo[4,5-c]pyridine, a structural unit in natural products
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The molecular structures and vibrational properties of 1H-imidazo[4,5-c] pyridine in its monomeric and dimeric forms are analyzed and related to the experimental results derived from the XRD, IR, and Raman studies. The theoretical data are discussed on the basis of DFT quantum chemical calculations using the B3LYP correlation functional and 6-311G(2d,2p) basis set. This compound crystallizes in the non-centrosymmetric orthorhombic space group Fdd2. The asymmetric unit contains one molecule of 1H-imidazo[4,5-c]pyridine and disordered molecules of solvents. The molecules are organized in hydrogen-bonded chains propagating along the [1 0 -3] direction. The stability of the dimeric form arising from charge delocalization and the existence of an N-H···N intermolecular hydrogen bond has been analyzed using the natural bond orbital approach. The normal modes, which are unique for the imidazopyridine skeleton, have been identified. The spectra of other compounds containing the imidazopyridine unit have been analyzed.
- Dyminska, Lucyna,Weiglinski, Zbigniew,Gaigor, Anna,Hanuza, Jerzy
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p. 1637 - 1646
(2013/10/22)
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- Lewis acid catalyst free synthesis of benzimidazoles and formamidines in 1,1,1,3,3,3-hexafluoro-2-propanol
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A simple, inexpensive, environmentally friendly and efficient route for the synthesis of benzimidazole and formamidine derivatives by the reaction of O-phenylenediamines or amines with orthoesters using hexafluoroisopropanol as a solvent/catalyst is described.
- Khaksar, Samad,Heydari, Akbar,Tajbakhsh, Mahmood,Vahdat, Seyed Mohammad
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experimental part
p. 1377 - 1381
(2011/02/22)
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- Structure-guided design of substituted aza-benzimidazoles as potent hypoxia inducible factor-1α prolyl hydroxylase-2 inhibitors
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We report the structure-based design and synthesis of a novel series of aza-benzimidazoles as PHD2 inhibitors. These efforts resulted in compound 22, which displayed highly potent inhibition of PHD2 function in vitro.
- Frohn, Mike,Viswanadhan, Vellarkad,Pickrell, Alexander J.,Golden, Jennifer E.,Muller, Kristine M.,Buerli, Roland W.,Biddlecome, Gloria,Yoder, Sean C.,Rogers, Norma,Dao, Jennifer H.,Hungate, Randall,Allen, Jennifer R.
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scheme or table
p. 5023 - 5026
(2009/05/26)
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- Facile synthesis of isoquinolines, β-carbolines, and 3-deazapurines
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Isoquinoline, β-carbolines, and 3-deazapurines were prepared in 52-81% yields via oxidative decarboxylation of cyclic α-amino acids using ammonium persulfate as an oxidant in the presence of catalytic silver. Copyright Taylor & Francis Group, LLC.
- Huang, Wenhua,Li, Jingyi,Ou, Lihua
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p. 2137 - 2143
(2008/02/07)
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- 3-nifro-3-deaza-2′-deoxyadenosine as a versatile photocleavable 2′-deoxyadenosine mimic
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A new photocleavable 2′-deoxyadenosine mimic, 3-nitro-3-deaza-2′-deoxyadenosine (NidA), was prepared and introduced into DNA fragments via its 6-O-trimethylphenyl precursor phophoramidite. Photocleavage of the resulting oligonucleotide is highly efficient
- Crey-Desbiolles, Caroline,Lhomme, Jean,Dumy, Pascal,Kotera, Mitsuharu
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p. 9532 - 9533
(2007/10/03)
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- Methyltrioxorhenium (MeReO3) catalyzed selective oxidation of purine and related compounds into their N-oxides
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A convenient method for the selective N-oxidation of purine, 6-methylpurine, 1H-imidazo[4,5-c]pyridine, 1H-imidazo[4,5-b]pyridine, 6-chloropurine, 6-bromopurine, and 7-azaindole by H2O2 catalyzed by methyltrioxorhenium is reported.
- Jiao,Yu
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- Piperazinyl derivatives of purines and isosteres thereof as hypoglycemic agents
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There are disclosed certain 6-piperazinopurines and heteroaromatic derivatives thereof which have oral hypoglycemic acitivity and with such ability to lower blood sugar are useful in the treatment of type II diabetes and/or obesity with associated insulin
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- Imidazopyridine derivatives and pharmaceutical compositions
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This invention relates to novel imidazopyridine derivatives useful in the treatment of diseases or disorders mediated by platelet-activating factor. This invention further relates to pharmaceutical compositions of such imidazopyridine derivatives.
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- 6-beta(substituted)-(S)-hydroxymethylpenicillanic acids and derivatives thereof
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Antibacterial penicillins of the formula STR1 or a pharmaceutically acceptable salt thereof wherein R1 is a heterocyclic group and R is hydrogen, the residue of certian carboxy protecting groups or the residue of an ester group readily hydrolyzable in vivo having activity against resistant organisms.
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- N,N-DIMETHYLCHLOROFORMIMINIUM CHLORIDE IN THE SYNTHESIS OF HETEROCYCLIC COMPOUNDS. THE SYNTHESIS OF N-HETEROARYLFORMAMIDINE HYDROCHLORIDES, OXAZOLO/5,4-D/PYRIMIDINES, FUSED IMIDAZOLES AND OTHER SYSTEMS
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N,N-Dimethylchloroformiminium chloride (DCFC) was used for preparation of N-heteroarylformamidine hydrochlorides (2), fused oxazoles (4), imidazoles (6,8) and thiazoles (10).DCFC is advantageous in those cases in which the undesired further methylation of NH, OH, and SH groups could occur by using N,N-dimethylformamide dimethyl acetal (DMFDMA).
- Stanovnik, Branko,Bajt, OLiver,Balcic, Branko,Koren, Bozidar,Prhavc, Marija,et al.
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p. 1545 - 1554
(2007/10/02)
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