- Visible light initiated oxidative coupling of alcohols ando-phenylenediamines to synthesize benzimidazoles over MIL-101(Fe) promoted by plasmonic Au
-
The use of visible light to initiate one-pot synergistic/cascade reactions is a green and energy saving strategy. In this manuscript, we report that MIL-101(Fe) can act as a multifunctional catalyst to realize the oxidative condensation betweeno-phenylenediamines and alcohols to synthesize benzimidazoles under visible light. The deposition of plasmonic Au nanoparticles (Au NPs) on MIL-101(Fe) led to significantly improved activity. Both controlled experiments and electron spin resonance (ESR) results revealed that the production of benzimidazoles fromo-phenylenediamines and alcohols involves three sequential steps,i.e., the oxidative dehydrogenation of alcohols to produce aldehydes, the condensation betweeno-phenylenediamines and the aldehydes to produce Schiff bases and their oxidation to form benzimidazoles,viaa superoxide radical (O2˙?)-mediated pathway. The promoting effect of plasmonic Au NPs in this reaction can be ascribed to the effective transfer of the surface plasmon resonance (SPR)-excited hot electrons to the lowest unoccupied molecular orbital (LUMO) of MIL-101(Fe), which led to the generation of more active O2˙?radicals. This study not only provides a green and sustainable way for the synthesis of benzimidazoles, but also highlights the great potential of using rationally designed plasmonic metal NP/MOF nanocomposites as multifunctional catalysts for light initiated one-pot tandem/cascade reactions.
- Hao, Mingming,Li, Zhaohui,Qin, Yuhuan,Xu, Chao
-
p. 4161 - 4169
(2021/06/17)
-
- Rhodium catalyzed 2-alkyl-benzimidazoles synthesis from benzene-1,2-diamines and tertiary alkylamines as alkylating agents
-
Substituted 2-alkyl-benzimidazoles were synthesized from benzene-1,2-diamine and tertiary amines as alkylating agent under polystyrene supported rhodium (Rh@PS) nanoparticles (NPs) catalyzed conditions. The heterogeneous rhodium catalyst was applied first time for the synthesis of 2-alkyl-benzimidazoles. The reaction followed through oxidation of alkylamines, transamination, and oxidative cyclisation with benzene-1,2-diamines for the corresponding products synthesis with good yields. The process is applicable for vast substrate scope, several functional groups are tolerable, and the Rh@PS catalyst is recyclable up to four cycles without significant loss in catalytic activity.
- Yamini,Sharma, Saurabh,Das, Pralay
-
-
- Sustainable photocatalytic synthesis of benzimidazoles
-
Among the 17 Sustainable Development Goals presented by the United Nations in 2015, great attention is devoted to the production of goods and chemicals by use of renewable raw materials, by recycling of products and by extensive use of renewable energy sources. In this context, photocatalysis attracted great attention for the possibility to exploit Solar light to promote the desired chemical reactions. Besides its use in degradation of pollutants and in the production of fuels, some efforts have been devoted in the development of photocatalytic processes for the synthesis of fine chemicals with high added-value. In this work, we investigated the sustainable photocatalytic synthesis of benzimidazole derivatives through a one-pot, tandem process starting from a nitro compound and ethanol. By a photocatalytic approach, ethanol is dehydrogenated producing the hydrogen required for reduction of nitro groups and the aldehyde required for cyclization and production of the benzimidazole unit. Co-doping of TiO2 with B and N is beneficial to increase the photocatalytic activity in H2 production from ethanol. The effect of various metal co-catalysts (Pt, Pd Ag, Cu) have been evaluated on H2 production rate and on selectivity in the synthesis of substituted benzimidazoles: Pt showed the highest selectivity in the desired products while Pd demonstrated a great activity for hydrodehalogenation, with potential interest for degradation of persistent pollutants.
- Montini, Tiziano,Gombac, Valentina,Delgado, Juan J.,Venezia, Anna Maria,Adami, Gianpiero,Fornasiero, Paolo
-
-
- Benzimidazoles and benzothiazoles from styrenes and N-vinylimidazole via palladium catalysed oxidative C[dbnd]C and C[sbnd]N bond cleavage
-
Herein we report a first, palladium catalyzed, one-pot methodology for the synthesis of pharmacologically important benzimidazoles and benzothiazoles from readily available terminal aromatic olefins. The process involves sequential C[dbnd]C/C[sbnd]N bond cleavage followed by C[sbnd]N/C[sbnd]S bond formation.
- Shaikh, Altab,Ravi, Owk,Pushpa Ragini,Sadhana, Nimma,Reddy Bathula, Surendar
-
supporting information
(2019/12/26)
-
- Supported Rhodium (Rh@PS) Catalyzed Benzimidazoles Synthesis Using Ethanol/Methanol as C2H3/CH Source
-
An effective and stable polystyrene supported rhodium (Rh@PS) nano-catalyst has been synthesized by following reduction-deposition approach and applied for the selective benzimidazoles synthesis from 1,2-phenylenediamines and ethanol/methanol as C2H3/CH source. The ethanol/methanol in the presence of trace amounts of aerobic oxygen under Rh@PS catalysed condition, first participated in oxidation of alcohol followed by consecutive condensation, cyclization and hydrogen elimination reactions with 1,2-phenylenediamine gave the desired products in good yields. The Rh@PS catalyst in a single system performed both oxidation and reduction reactions in a selective/specific manner and applied for large substrate scope. Easy recovery, handling, stability, recyclability of the catalyst and less chance of metal contamination with the products are the added advantages of the process. (Figure presented.).
- Sharma, Saurabh,Sharma, Ajay,Yamini,Das, Pralay
-
supporting information
p. 67 - 72
(2018/12/05)
-
- Oxalic/malonic acids as carbon building blocks for benzazole, quinazoline and quinazolinone synthesis
-
An oxidant, base and metal free methodology has been developed for the synthesis of various 2-substituted and non-substituted benzazoles, quinazolines and quinazolinones using oxalic/malonic acids as an in situ carbon source. This methodology is applicable for a wide range of substituted o-phenylenediamine, o-aminothiophenol, o-aminophenol and o-aminobenzamide containing various functional groups and provides good to excellent yields of the corresponding product. Furthermore an easy workup procedure, high yield and easy isolation of products are key features of this methodology. The developed protocol is also applicable for the gram scale synthesis of benzimidazoles.
- Sharma, Saurabh,Bhattacherjee, Dhananjay,Das, Pralay
-
supporting information
p. 1337 - 1342
(2018/03/06)
-
- Derisking the Cu-Mediated 18F-Fluorination of Heterocyclic Positron Emission Tomography Radioligands
-
Molecules labeled with fluorine-18 (18F) are used in positron emission tomography to visualize, characterize and measure biological processes in the body. Despite recent advances in the incorporation of 18F onto arenes, the development of general and efficient approaches to label radioligands necessary for drug discovery programs remains a significant task. This full account describes a derisking approach toward the radiosynthesis of heterocyclic positron emission tomography (PET) radioligands using the copper-mediated 18F-fluorination of aryl boron reagents with 18F-fluoride as a model reaction. This approach is based on a study examining how the presence of heterocycles commonly used in drug development affects the efficiency of 18F-fluorination for a representative aryl boron reagent, and on the labeling of more than 50 (hetero)aryl boronic esters. This set of data allows for the application of this derisking strategy to the successful radiosynthesis of seven structurally complex pharmaceutically relevant heterocycle-containing molecules.
- Taylor, Nicholas J.,Emer, Enrico,Preshlock, Sean,Schedler, Michael,Tredwell, Matthew,Verhoog, Stefan,Mercier, Joel,Genicot, Christophe,Gouverneur, Véronique
-
supporting information
p. 8267 - 8276
(2017/06/27)
-
- Gadolinium (III) chloride catalyzed facile synthesis of 2-substituted benzimidazoles under solvent-free conditions
-
A series of 2-substituted benzimidazoles have been prepared from o-diamines and 1,3-dicarbonyl compounds using Gadolinium chloride as a catalyst under solvent free condition in good yields. Gadolinium chloride has been demonstrated as a mild and efficient catalyst.
- Sathaiah,Venkat Lingaiah,Chandra Shekhar,Ravi Kumar,Raju,Shanthan Rao
-
p. 953 - 957
(2015/08/19)
-
- Synthesis of Mavatrep: A Potent Antagonist of Transient Receptor Potential Vanilloid-1
-
The process development of Mavatrep (1), a potent transient receptor potential vanilloid-1 (TRPV1) antagonist, is described. The two key synthetic transformations are the synthesis of (E)-6-bromo-2-(4-(trifluoromethyl)styryl)1H-benzo[d]imidazole (4) and the Suzuki coupling of 4 with 3,3-dimethyl-3H-benzo[c][1,2]oxaborol-1-ol (5). Compound 1a was prepared in four chemical steps in 63% overall yield.
- Wells, Kenneth M.,Mehrman, Steven J.,Abdel-Magid, Ahmed F.,Ferraro, Caterina,Scott, Lorraine,Zhong, Hua Marlon,Teleha, Christopher A.,Ballentine, Scott,Li, Xun,Russell, Ronald K.,Spink, Jan M.,Diamond, Craig,Youells, Scott,Zhang, Yongzheng,Tsay, Fuh-Rong,Cesco-Cancia, Sergio,Manzo, Stephen M.,Beauchamp, Derek A.
-
p. 1774 - 1783
(2015/12/01)
-
- Novel fatty acid binding protein 4 (FABP4) inhibitors: Virtual screening, synthesis and crystal structure determination
-
Fatty acid binding protein 4 (FABP4) is a potential drug target for diabetes and atherosclerosis. For discovering new chemical entities as FABP4 inhibitors, structure-based virtual screening (VS) was performed, bioassay demonstrated that 16 of 251 tested compounds are FABP4 inhibitors, among which compound m1 are more active than endogenous ligand linoleic acid (LA). Based on the structure of m1, new derivatives were designed and prepared, leading to the discovery of two more potent inhibitors, compounds 9 and 10. To further explore the binding mechanisms of these new inhibitors, we determined the X-ray structures of the complexes of FABP4-9 and FABP4-10, which revealed similar binding conformations of the two compounds. Residue Ser53 and Arg126 formed direct hydrogen bonding with the ligands. We also found that 10 could significantly reduce the levels of lipolysis on mouse 3T3-L1 adipocytes. Taken together, in silico, in vitro and crystallographic data provide useful hints for future development of novel inhibitors against FABP4.
- Cai, Haiyan,Liu, Qiufeng,Gao, Dingding,Wang, Ting,Chen, Tiantian,Yan, Guirui,Chen, Kaixian,Xu, Yechun,Wang, Heyao,Li, Yingxia,Zhu, Weiliang
-
p. 241 - 250
(2014/12/12)
-
- Weinreb amide as an efficient reagent in the one pot synthesis of benzimidazoles and benzothiazoles
-
One pot synthesis of 2-substituted benzimidazoles/benzothiazoles through condensation is followed by cyclization of Weinreb amide with o-diaminoarene or o-aminothiophenol is reported. In the presence of boron trifluoride etherate in 1,4-dioxane solvent, a high yield (75-94%) was achieved within 60 min. Weinreb amide shows high selectivity in the reaction, even in presence of other active functional groups such as carboxyl, halogen, cyano, and methoxy.
- Bommegowda, Yadaganahalli K.,Lingaraju, Gejjalagere S.,Thamas, Saji,Vinay Kumar, Koravangala S.,Pradeepa Kumara, Challanayakanahally S.,Rangappa, Kanchugarakoppal S.,Sadashiva, Marilinganadoddi P.
-
supporting information
p. 2693 - 2695
(2013/06/05)
-
- A PdII complex bearing a benzimidazole-derived ligand with potentially "mesoionic and remote" character and its catalytic activity
-
The oxidative addition of palladium(0) to the C2-protected 5-bromo-2-methylbenzimidazolium tetrafluoroborate 3 affords the complex trans-[PdBr(bimy)(PPh3)2]BF4 (4), which is the first complex of an unprecedented benzimidaz
- Huynh, Han Vinh,Ong, Hong Lee,Bernhammer, Jan C.,Frison, Gilles
-
p. 4654 - 4661
(2013/09/23)
-
- Indium-mediated one-pot benzimidazole synthesis from 2-nitroanilines or 1,2-dinitroarenes with orthoesters
-
One-pot reduction-triggered heterocyclizations from 2-nitroanilines or 1,2-dinitroarenes to benzimidazoles were investigated in this study. In the presence of indium/AcOH in ethyl acetate at reflux, reaction of 2-nitroanilines or 1,2-dinitroarenes with R-C(OMe)3 (R=Me, Ph) produced excellent yields of the corresponding benzimidazoles within 30 min to 6 h depending on the substituents of the starting materials. Indium-mediated heterocyclization of 2-nitroanilines to benzimidazole was faster and had better yields than 1,2-dinitroarenes to benzimidazole under similar reaction conditions.
- Kim, Jaeho,Kim, Jihye,Lee, Hyunseung,Lee, Byung Min,Kim, Byeong Hyo
-
experimental part
p. 8027 - 8033
(2011/11/06)
-
- PYRROLO-PYRIDINE KINASE MODULATORS
-
The present invention provides novel pyrrolo-pyridine kinase modulators and methods of using the novel pyrrolo-pyridine kinase modulators to treat diseases mediated by kinase activity.
- -
-
Page/Page column 89
(2008/12/04)
-
- Copper-catalyzed synthesis of benzimidazoles via cascade reactions of o-haloacetanilide derivatives with amidine hydrochlorides
-
(Chemical Equation Presented) We have developed an efficient method for the synthesis of benzimidazoles via cascade reactions of o-haloacetoanilide derivatives with amidine hydrochlorides. The protocol uses 10 mol % CuBr as the catalyst, CS2CO
- Yang, Daoshan,Fu, Hua,Hu, Liming,Jiang, Yuyang,Zhao, Yufen
-
p. 7841 - 7844
(2008/12/22)
-
- MORPHOLINO PYRIMIDINE DERIVATIVES AND THEIR USE IN THERAPY
-
A compound of formula (I) or a salt, ester or prodrug thereof, processes for their preparation, pharmaceutical compositions containing them and their use in therapy, for example in the treatment of proliferative disease such as cancer and particularly in disease mediated by an mTOR kinase and/or one or more PI3K enzyme.
- -
-
Page/Page column 132-133
(2008/06/13)
-
- Pyrrolo-pyridine kinase modulators
-
The present invention provides novel pyrrolo-pyridine kinase modulators and methods of using the novel pyrrolo-pyridine kinase modulators to treat diseases mediated by kinase activity.
- -
-
Page/Page column 73
(2010/02/15)
-
- Reductive cyclization with baker's yeast of 4-alkyl-2-nitro-acetanilides to 6-alkylbenzimidazoles and 1-hydroxy-2-methyl-6-alkylbenzimidazoles
-
Reduction of 4-substituted 2-nitroacetanilides by baker's yeast in acid media effected cyclization, resulting in the formation of n-substituted 2-methylbenzimidazoles and 6-substituted 1-hydroxy-2-methylbenzimidazole via the chemo- and regioselective reduction of the 2-nitro aromatic group to amine or hydroxylamine.
- Navarro-Ocana,Olguin,Luna,Jimenez-Estrada,Barzana
-
p. 2754 - 2756
(2007/10/03)
-
- Study of unsaturated azoles. 16 Synthesis and reactions of 2-styrylbenzimidazoles
-
Fusion of 1-methyl-2-styrylbenzimidazole with KOH leads to separation of the phenylvinyl or the N-methyl group to give 1-methylbenzimidazol-2-one or 2-styrylbenzimidazole in the ratio 1:1. Decomposition of the perbromides of benzimidazoles by heating in water gives 5(6)-bromobenzimidazoles and, in the presence of KI, to 5(6)-iodobenzimidazoles. Methods are presented for the synthesis of 5(6)-bromo- and 5(6)-iodo-2-styryl- and also 2-α-bromo- and 2-α-iodostyrylbenzimidazoles. 1998 Plenum Publishing Corporation.
- Popov
-
p. 949 - 953
(2007/10/03)
-
- A SUPERIOR SYNTHETIC METHOD FOR THE BROMINATION OF INDOLES AND BENZIMIDAZOLES.
-
Brominated indoles and benzimidazoles are formed in very high yields and with substantial regioselectivity by use of a reagent system consisting of N-bromosuccinimide (NBS) and silica gel in dichloromethane.
- Mistry, Anil G.,Smith, Keith,Bye, Martin R.
-
p. 1051 - 1054
(2007/10/02)
-