- Lewis acid mediated, mild C-H aminoalkylation of azolesviathree component coupling
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This manuscript reports the development of a mild, highly functional group tolerant and metal-free C-H aminoalkylation of azolesviaa three-component coupling approach. This method enables the C-H functionalization of diverse azole substrates, such as oxazoles, benzoxazoles, thiazoles, benzothiazoles, imidazoles, and benzimidazoles. DFT calculations identify a key deprotonation equilibrium in the mechanism of the reaction. Using DFT as a predictive tool, the C-H aminoalkylation of initially unreactive substrates (imidazoles/benzimidazoles) can be enabled through anin situprotecting/activating group strategy. The DFT-supported mechanistic pathway proposes key interactions between the azole substrate and the Lewis acid/base pair TBSOTf/EtNiPr2that lead to azole activation by deprotonation, followed by C-C bond formation between a carbene intermediate and an iminium electrophile. Two diverse approaches are demonstrated to explore the amine substrate scope: (i) a DFT-guided predictive analysis of amine components that relates reactivity to distortion of the iminium intermediates in the computed transition state structures; and (ii) a parallel medicinal chemistry workflow enabling synthesis and isolation of several diversified products at the same time. Overall, the presented work enables a metal-free approach to azole C-H functionalizationviaLewis acid mediated azole C-H deprotonation, demonstrating the potential of a readily available, Si-based Lewis acid to mediate new C-C bond formations.
- Emmert, Marion H.,He, Cyndi Qixin,Shah, Akshay A.,Felten, Stephanie
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- Phenyliodine diacetate-mediated intramolecular C(sp2)-H amidation for 1,2-disubstituted benzimidazole synthesis under metal-free conditions
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A transition metal-free, hypervalent iodine(III) reagent [phenyliodine diacetate (PIDA)]-mediated C(sp2)-H amidation in trifluoroethanol (TFE) has been developed. The intramolecular coupling methodology presented here provides a direct access t
- Maiti, Saikat,Mal, Prasenjit
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- Electrochemical Oxidative Amination of Sodium Sulfinates: Synthesis of Sulfonamides Mediated by NH4I as a Redox Catalyst
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An efficient protocol for the synthesis of sulfonamides via the electrochemical oxidative amination of sodium sulfinates has been developed. The chemistry proceeds in a simple undivided cell employing a substoichiometric amount of NH4I that serves both as a redox catalyst and a supporting electrolyte; in this manner additional conducting salt is not required. A wide range of substrates, including aliphatic or aromatic secondary and primary amines, as well as aqueous ammonia, proved to be compatible with the protocol. Scale-up was possible, thereby demonstrating the practicality of the approach. The electrolytic process avoids the utilization of external oxidants or corrosive molecular iodine and therefore represents an environmentally benign means by which to achieve the transformation.
- Jiang, Yang-Ye,Wang, Qing-Qing,Liang, Sen,Hu, Li-Ming,Little, R. Daniel,Zeng, Cheng-Chu
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- A facile and versatile electro-reductive system for hydrodefunctionalization under ambient conditions
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A general electrochemical system for reductive hydrodefunctionalization is described, employing the inexpensive and easily available triethylamine (Et3N) as a sacrificial reductant. This protocol is characterized by facile operation, sustainable conditions, and exceptionally wide substrate scope covering the cleavage of C-halogen, N-S, N-C, O-S, O-C, C-C and C-N bonds. Notably, the selectivity and capability of reduction can be conveniently switched by simple incorporation or removal of an alcohol as a co-solvent.
- Huang, Binbin,Guo, Lin,Xia, Wujiong
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supporting information
p. 2095 - 2103
(2021/03/26)
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- Electron Transfer Photoredox Catalysis: Development of a Photoactivated Reductive Desulfonylation of an Aza-Heteroaromatic Ring
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Herein, we report a protocol for desulfonylation of aza-heteroaromatic rings via photoinduced electron transfer and hydrogen atom transfer. This general protocol has a wide substrate range and moderate to good yields. The utility of the method was demonstrated by the chemoselective desulfonylation of a molecule containing both an aliphatic and an aromatic sulfonamide. (Figure presented.).
- Qiang-Liu,Liu, Yu-Xiu,Song, Hong-Jian,Wang, Qing-Min
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supporting information
p. 3110 - 3115
(2020/07/04)
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- Cu-catalyzed dehydrogenative olefinsulfonation of Alkyl arenes
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A copper-catalyzed reaction protocol for the dehydrogenation of ethylbenzenes into styrene derivatives has been developed. This reaction procedure proceeded well under mild reaction conditions, providing a practical and efficient strategy for the rapid assembly of biologically and pharmaceutically significant molecules, such as vinyl sulfone. Simple alkyl arenes were functionalized via consecutive β-elimination in the presence of N-sulfonylbenzo[d]imidazole with broad substrate scope and good functional group tolerance.
- Li, Fangfang,Zhang, Guang'an,Liu, Yingguo,Zhu, Bingke,Leng, Yuting,Wu, Junliang
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supporting information
p. 8791 - 8795
(2020/11/30)
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- Facile access to: N-formyl imide as an N-formylating agent for the direct synthesis of N-formamides, benzimidazoles and quinazolinones
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N-Formamide synthesis using N-formyl imide with primary and secondary amines with catalytic amounts of p-toluenesulfonic acid monohydrate (TsOH·H2O) is described. This reaction is performed in water without the use of surfactants. Moreover, N-formyl imide is efficiently synthesized using acylamidines with TsOH·H2O in water. In addition, N-formyl imide was successfully used as a carbonyl source in the synthesis of benzimidazole and quinazolinone derivatives. Notable features of N-formylation of amines by using N-formyl imide include operational simplicity, oxidant- A nd metal-free conditions, structurally diverse products, and easy applicability to gram-scale operation.
- Huang, Hsin-Yi,Liang, Chien-Fu,Lin, Xiu-Yi,Yen, Shih-Yao
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supporting information
p. 5726 - 5733
(2020/08/21)
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- Design, synthesis and molecular docking studies of novel N-arylsulfonyl-benzimidazoles with anti Trypanosoma cruzi activity
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Currently, only two drugs (i.e. benznidazole (BZN) and nifurtimox (NFX)) have been approved for the treatment of Trypanosoma cruzi (Tc) infection, the etiological agent causing Chagas disease. Since both drugs exhibit severe side effects, patients frequently abandon therapy, resulting in an inefficient pharmacotherapeutic treatment. In this context, there is an urgent need to develop new, safer and optimised anti-Tc agents. In this report, we present the synthesis and biological activity of 11 novel and 3 already reported N-arylsulfonyl-benzimidazole derivatives (NBSBZD,1–14) currently in development as potential anti-Tc compounds. These compounds were designed as part of a library of synthetic arylsulfonyl heterocycle derivatives constructed from privileged structures exhibiting drug-like properties. Based on bioactivity assays against Tc, (in both the extracellular and intracellular forms), we observed that 10 compounds exhibited bioactivity against the epimastigote form, while six of them exhibited activity against the amastigote counterpart. Also, the compounds showed less cytotoxicity compared to the reference drug BZN as measured in Vero cell culture. In order to elucidate the potential mechanism of action, metabolite excretion profiles studies were performed, and complemented with molecular modeling studies performed over known Tc druggable targets. Consistency was observed between experimental and theoretical findings, with metabolic profiles showing that compounds 1, 2, 9, 12 and 14 interfered with the normal glycolysis cycle of Tc, while molecular modeling studies were able to establish a solid structure-activity relationship towards the inhibition of 6-phospho-1-fructokinase, a key enzyme involved in the parasite glycolytic cascade. Overall, the present study constitutes a multidisciplinary contribution to the development of new anti-Chagas compounds.
- Miana, Gisele E.,Ribone, Sergio R.,Vera, Domingo M.A.,Sánchez-Moreno, Manuel,Mazzieri, María R.,Quevedo, Mario A.
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- Molecular modeling, synthesis, antibacterial and cytotoxicity evaluation of sulfonamide derivatives of benzimidazole, indazole, benzothiazole and thiazole
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A new series of heterocyclic molecules bearing sulfonamide linkage has been synthesized and screened for antibacterial activity. During antibacterial screening using broath dilution method, molecules were found to be highly active (MIC value 50–3.1 μg/mL)
- Naaz, Farha,Srivastava, Ritika,Singh, Anuradha,Singh, Nidhi,Verma, Rajesh,Singh, Vishal K.,Singh, Ramendra K.
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p. 3414 - 3428
(2018/05/23)
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- Synthesis, characterization, antitumor, antibacterial and urease inhibitory activity of a small series of N-tosyl benzimidazoles
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Benzimidazole derivatives exhibited a broad range of biological activities, e.g., antimicrobial, antiviral, anthelmintic, anti-inflammatory, anticancer and as an anti-ulcer/proton pump inhibitor. Keeping in view the large number of reported drugs containing benzimidazole moiety on one hand and sulfonamide on the other hand, a small series of N-tosyl benzimidazoles (4a-e) have been synthesized. The present work describes the synthesis, characterization and bio-evaluation of five new N-tosyl benzimidazoles with the objective to develop new compounds with improved anticancer, antibacterial and urease inhibitory activities. The substituted 1,2-phenylenediamines in the first step were condensed with aliphatic carboxylic acids to synthesize the substituted benzimidazoles. In the second step the tosyl chloride was reacted with substituted benzimidazoles in basic conditions to afford the title N-tosyl benzimidazoles (4a-e). The screening for their antitumor activities was performed against Agrobacterium tumefaciens by following the potato disc tumor assay. The compound (4e) exhibited excellent antitumor activity with IC50 values 474.45μgml-1 compared to other synthesized compounds. Antibacterial activity results revealed that compounds 4d and 4e having methyl and ethyl substitution respectively at the imidazole ring showed excellent zone inhibition against both gram positive and gram negative strains. The urease inhibitory activity results showed that derivative 4e exhibited highest potential to inhibit the urease enzyme compared to all other derivatives. Based upon our investigation it is proposed that compound (4e) may serve as lead structure to design more potent biological active compounds having multitargets inhibition activities.
- Rashid, Naghmana,Kiran, Almas,Ashraf, Zaman,Bhatti, Moazzam Hussain,Mirza, Bushra,Ismail, Hammad,Rafiq, Muhammad,Jasinski, Jerry P.
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p. 366 - 374
(2018/06/06)
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- Selective C-H trifluoromethylation of benzimidazoles through photoredox catalysis
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The protocol presented here is a new strategy for visible light induced C-H trifluoromethylation at C4 of benzimidazoles using Togni's reagent in the presence of fac-Ir(ppy)3. Its advantages are its operational simplicity, mild reaction conditions, low catalyst loading and wide substrate scope in which electron-withdrawing, electron-donating groups and different protecting groups are tolerated.
- Gao, Guo-Lin,Yang, Chao,Xia, Wujiong
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p. 1041 - 1044
(2017/02/05)
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- Synthesis of sulfonamides from azoles and sodium sulfinates at ambient temperature
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NBS or NIS mediated direct S[sbnd]N bond formation between azoles and sodium sulfinates is described. The reaction shows good substrate scope and tolerates a wide range of functionalities in both azoles and sodium sulfinate substrates. Pyrazoles are also suitable for this method, various 4-halopyrazoles derivatives were obtained by using N-halosuccinimide (NXS) as the halogen source.
- Fu, Lili,Bao, Xiaodong,Li, Shanshan,Wang, Lingtian,Liu, Zhiguo,Chen, Wanzhi,Xia, Qinqin,Liang, Guang
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p. 2504 - 2511
(2017/04/03)
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- Preparation method of N-substituted sulfonamide derivative
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The invention discloses a preparation method of N-substituted sulfonamide derivative. The preparation method includes the following steps: taking NBS or NIS as an oxidizing agent; reacting an azole compound and sodium arylsulfinate in an organic solvent;
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Paragraph 0076; 0077; 0078; 0079; 0080; 0081
(2016/10/08)
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- Sulfonamide formation from sodium sulfinates and amines or ammonia under metal-free conditions at ambient temperature
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A novel, practical and highly efficient method for the construction of a variety of sulfonamides mediated by I2 was demonstrated. The reaction proceeds readily at room temperature using a variety of sodium sulfinates and amines or ammonia in water in a metal-, base-, ligand-, or additive-free protocol. Primary, secondary and tertiary sulfonamides were obtained in good to excellent yields with a broad range of functional group tolerability. This journal is
- Yang, Kai,Ke, Miaolin,Lin, Yuanguang,Song, Qiuling
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supporting information
p. 1395 - 1399
(2015/03/18)
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- Development of a concise, asymmetric synthesis of a smoothened receptor (smo) inhibitor: Enzymatic transamination of a 4-piperidinone with dynamic kinetic resolution
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A concise, asymmetric synthesis of a smoothened receptor inhibitor (1) is described. The synthesis features an enzymatic transamination with concurrent dynamic kinetic resolution (DKR) of a 4-piperidone (4) to establish the two stereogenic centers required in a single step. This efficient reaction affords the desired anti amine (3) in >10:1 dr and >99% ee. The title compound is prepared in only five steps with 40% overall yield.
- Peng, Zhihui,Wong, John W.,Hansen, Eric C.,Puchlopek-Dermenci, Angela L. A.,Clarke, Hugh J.
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supporting information
p. 860 - 863
(2014/03/21)
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- Benzazoles 5*. synthesis and arylsulfonylation of 1-hydroxymethylbenzimidazole
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1-Hydroxymethylbenzimidazole was synthesized by the reaction of benzimidazole with formaldehyde. Arylsulfonylation of the former in the presence of triethylamine occurred anomalously with deformylation to give 1-arylsulfonylbenzimidazoles in place of the
- Abdireimov,Mukhamedov,Aiymbetov,Shakhidoyatov
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p. 458 - 461
(2012/10/29)
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- Identification of inhibitors of NOD1-induced nuclear factor-κB activation
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NOD1 (nucleotide-binding oligomerization domain 1) protein is a member of the NLR (NACHT and leucine rich repeat domain containing proteins) protein family, which plays a key role in innate immunity as a sensor of specific microbial components derived from bacterial peptidoglycans and induction of inflammatory responses. Mutations in NOD proteins have been associated with various inflammatory diseases that affect NF-κB (nuclear factor κB) activity, a major signaling pathway involved in apoptosis, inflammation, and immune response. A luciferase-based reporter gene assay was utilized in a high-throughput screening program conducted under the NIH-sponsored Molecular Libraries Probe Production Center Network program to identify the active scaffolds. Herein, we report the chemical synthesis, structure-activity relationship studies, downstream counterscreens, secondary assay data, and pharmacological profiling of the 2-aminobenzimidazole lead (compound 1c, ML130) as a potent and selective inhibitor of NOD1-induced NF-κB activation.
- Khan, Pasha M.,Correa, Ricardo G.,Divlianska, Daniela B.,Peddibhotla, Satyamaheshwar,Sessions, E. Hampton,Magnuson, Gavin,Brown, Brock,Suyama, Eigo,Yuan, Hongbin,Mangravita-Novo, Arianna,Vicchiarelli, Michael,Su, Ying,Vasile, Stefan,Smith, Layton H.,Diaz, Paul W.,Reed, John C.,Roth, Gregory P.
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supporting information; experimental part
p. 780 - 785
(2011/12/02)
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- Benzazoles. 3*. Synthesis and arylsulfonylation of 2-substituted benzimidazoles
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2-Alkylbenzimidazoles have been obtained from o-nitroaniline and aliphatic carboxylic acids by reductive cyclization. Interaction of the former with arenesulfonyl chlorides led to the synthesis of 2-alkyl-1- arylsulfonylbenzimidazoles, the yield of which depended on the structure of the substituent in position 2.
- Abdireimov,Mukhamedov,Aiymbetov,Shakhidoyatov
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experimental part
p. 941 - 946
(2011/09/20)
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- Polyethyleneglycol Catalysed N-Sulphonylation and N-Benzoylation of Substituted Benzimidazoles
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Benzenesulphonyl chloride and p-toluenesulphonyl chloride react with benzimidazole and 2-phenylbenzimidazole in benzene and 50percent aqueous sodium hydroxide in the presence of polyethyleneglycol 400 or triethylbenzylammonium chloride to afford the corresponding N-sulphonyl derivatives.However, 2-methylbenzimidazole affords both N-sulphonylated and C-sulphonylated products.N-Benzoylation is also effected under similar conditions using benzoyl chloride.
- Kumar, P. Raja
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p. 1273 - 1274
(2007/10/02)
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