- DMF-Assisted Radical Cyclization of o-Isocyanodiaryl Ethers via 1,5-Aryl Migration: Construction of 2-Arylbenzoxazoles
-
A novel DMF-assisted radical cyclization of o-isocyanodiaryl ethers via 1,5-aryl migration has been developed for the synthesis of a series of 2-arylbenzoxazoles by the FeCl3/TBHP/Et3N catalytic system in DMF. However, N,N-dimethylbenzo[d]thiazole-2-carboxamide and N,N-dimethylbenzo[d]selenazole-2-carboxamide were obtained from the corresponding substrate 2-isocyanophenyl p-methoxyphenyl thioether and 2-isocyanodiphenyl selenoether under the same conditions. A possible mechanism may involve aryl 1,5-migration and DMF-assisted radical cyclization of o-isocyanodiaryl ethers.
- Cai, Jingyu,Ding, Qiuping,Peng, Yiyuan,Song, Zhibin,Tan, Yuxing,Ye, Xiaoling,Yuan, Sitian
-
p. 1485 - 1492
(2022/01/20)
-
- ORGANIC COMPOUNDS AND ORGANIC LIGHT EMITTING DISPLAY DEVICE USING THE SAME
-
The present disclosure relates to an organic compound and an organic light emitting display device using the same wherein the organic compound is represented by Chemical Formula 1 and a display device using the organic compound. The organic compound represented by Chemical Formula 1 has excellent electron transport properties and durability and is used for an electron transport layer of an organic light emitting element, thereby lowering a driving voltage and improving the luminous efficiency and lifetime. (In the above Chemical Formula 1, at least two of X1, X2 and X3 are N, Y1 and Y2 are each independently a substituted or unsubstituted phenylene group or a single bond, at least one of Ar1 and Ar2 is selected from a substituted or unsubstituted triazine group, a functional group represented by Chemical Formula 2 and a functional group represented by Chemical Formula 3.)
- -
-
-
- A TEMPO-Functionalized Ordered Mesoporous Polymer as a Highly Active and Reusable Organocatalyst
-
The properties of high stability, periodic porosity, and tunable nature of ordered mesoporous polymers make these materials ideal catalytic nanoreactors. However, their application in organocatalysis has been rarely explored. We report herein for the first time the incorporation of a versatile organocatalyst, 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), into the pores of an FDU-type mesoporous polymer via a pore surface engineering strategy. The resulting FDU-15-TEMPO possesses a highly ordered mesoporous organic framework and enhanced stability, and shows excellent catalytic activity in the selective oxidation of alcohols and aerobic oxidative synthesis of 2-substituted benzoxazoles, benzimidazoles and benzothiazoles. Moreover, the catalyst can be easily recovered and reused for up to 7 consecutive cycles.
- Guo, Ying,Wang, Wei David,Li, Shengyu,Zhu, Yin,Wang, Xiaoyu,Liu, Xiao,Zhang, Yuan
-
supporting information
p. 3689 - 3694
(2021/09/29)
-
- Heterogeneous palladium (II)-complexed dendronized polymer: A rare palladium catalyst for the one-pot synthesis of 2-arylbenzoxazoles
-
The palladium complex of dendronized amine polymer (EG–Gn–Pd, n = 0, 1 and 2) having ethylene glycol-initiated polyepichlorohydrin as core was synthesized on a Merrifield resin support and was well characterized. Generally, palladium catalysts are known for carbon–carbon coupling reactions. Here, a developed catalyst was found to be good for benzoxazole synthesis. Higher generation dendronized polymer (EG–G2–Pd) was found to be better catalyst over lower generation dendronized polymers. Moreover, dendronized polymers were found to be a better catalyst over dendrigraft polymers. The catalyst reusability was checked and good yield was obtained for five cycles.
- George, Smitha,Sreekumar, Krishnapillai
-
-
- In-vitro Anti-cancer assay and apoptotic cell pathway of newly synthesized benzoxazole-N-heterocyclic hybrids as potent tyrosine kinase inhibitors
-
A series of benzoxazole-N-heterocyclic hybrids have been synthesized by a one-pot strategy. Molecular docking study revealed that such compounds have the ability to inhibit enzyme protein tyrosine kinase. The findings of this work have been the successful synthesis of benzoxazole scaffolds, featuring hybrids of benzoxazole with quinoline and quinoxaline respectively. The molecular docking studies have showed these compounds to be inhibitors of tyrosine kinase enzyme which triggers growth of cancer cells. The cytotoxicity study of compounds 4a-f showed better potency against breast cancer cell lines MCF-7 and MDA-MB-231 in contrast to oral and lung cancer cell lines KB and A549. The tyrosine kinase activity was measured using Universal Tyrosine Kinase Assay kit using horseradish peroxide (HRP)-conjugated anti-phosphotyrosine kinase solution as a substrate. The compounds 4c exhibited maximum inhibition in the activity of enzyme tyrosine kinase with IC50 value 0.10 ± 0.16 μM, than other compounds which were studied and thus proved to be inhibitors of enzyme tyrosine kinase. The selective index of all four compounds was found out to be greater than two, indicating the non-toxic behaviour, i.e. good anti-cancer activity. Further, fluorescence microscopic study helped to characterize the mode of cell death, which was found to be late apoptosis as indicated by the orange fluorescence. The SAR analysis has also been carried out.
- Desai, Sulaksha,Desai, Vidya,Shingade, Sunil
-
supporting information
(2019/11/13)
-
- Iodine Promoted One-Pot Synthesis of 2-Aryl Benzoxazoles from Amidoximes via Oxidative Cyclization and Ring Contraction
-
A molecular I2-promoted one-pot synthesis of 2-aryl benzoxazoles has been developed by using amidoximes rather than the limited 2-aminophenols or 2-haloamides as substrates. The amidoxime substrates provided unique and efficient strategies for converting readily available aniline and benzaldehyde precursors into valuable chemicals. This transformation proceeded smoothly under transition-metal-free conditions through a sequential oxidative cyclization and ring contraction, and provided a potential route for introducing certain groups at any site of the scaffold.
- Zhang, Yong,Ji, Min
-
supporting information
p. 7506 - 7510
(2019/11/28)
-
- Tribenzazole amine derivatives and organic electroluminescent device including the same
-
The present invention provides a tribenzazole amine derivative which contributes to substantial life improvement of an organic electroluminescent device by effectively absorbing a high energy external light source of an UV area and minimizing the damage of organic materials in the organic electroluminescent device. The organic electroluminescent device according to the present invention includes: a first electrode; a second electrode; an organic material layer disposed between the first electrode and the second electrode; and a capping layer disposed on the second electrode. The capping layer includes a tribenzazole amine derivative represented by chemical formula 1. In chemical formula 1, R^1, R^2 and R^3 are the same as or different from each other and are respectively and independently hydrogen and an alkyl group having 1 to 10 carbon atoms. l, n, and m are integers of 0 to 4.COPYRIGHT KIPO 2020
- -
-
-
- Synthesis of Benz-Fused Azoles via C-Heteroatom Coupling Reactions Catalyzed by Cu(I) in the Presence of Glycosyltriazole Ligands
-
Glycosyl triazoles are conveniently accessible and contain multiple metal-binding units that may assist in metal-mediated catalysis. Azide derivatives of d-glucose have been converted to their respective aryltriazoles and screened as ligands for the synthesis of 2-substituted benz-fused azoles and benzimidazoquinazolinones by Cu-catalyzed intramolecular Ullmann type C-heteroatom coupling. Good to excellent yields for a variety of benz-fused heterocyles were obtained for this readily accessible catalytic system.
- Mishra, Nidhi,Singh, Anoop S.,Agrahari, Anand K.,Singh, Sumit K.,Singh, Mala,Tiwari, Vinod K.
-
supporting information
p. 389 - 399
(2019/05/06)
-
- Transition-Metal-Free Alkylation/Arylation of Benzoxazole via Tf2O-Activated-Amide
-
A transition-metal-free approach to the alkylation/arylation of benzoxazole was developed by employing Tf2O-activated-amide as the alkylating/arylating reagent. The mild reaction conditions, and particularly insensitivity to air and water, further enhance the synthetic potential in pharmaceutical synthesis. (Figure presented.).
- Niu, Zhi-Jie,Li, Lian-Hua,Liu, Xue-Yuan,Liang, Yong-Min
-
p. 5217 - 5222
(2019/11/13)
-
- Continuous flow/waste-minimized synthesis of benzoxazoles catalysed by heterogeneous manganese systems
-
Herein, we present our results on the development of a waste minimized protocol for the synthesis of 2-arylbenzoxazoles in continuous flow. Manganese-based heterogeneous catalysts were used in combination with cyclopentylmethyl ether as an environmentally friendly and safe reaction medium. The use of oxygen promotes the oxidative process ensuring at the same time a complete regeneration of the catalyst adopting a flow configuration which does not include the use of an additional mechanical pump. These features allowed for a faster synthesis compared to batch procedures with minimal metal leaching.
- Ferlin, Francesco,Van Der Hulst, Mitchell K.,Santoro, Stefano,Lanari, Daniela,Vaccaro, Luigi
-
supporting information
p. 5298 - 5305
(2019/10/11)
-
- Method for synthesizing benzoxazole through microwave radiation of benzamide compound in water phase
-
The invention discloses a method for synthesizing benzoxazole through microwave radiation of a benzamide compound in a water phase. The benzamide compound is added into the water phase under the microwave condition to be subjected to a cyclization reaction for generating the benzoxazole under the alkali condition, and the method for preparing the benzoxazole is environmentally friendly, easy and convenient to operate, safe, low in cost and efficient. Compared with the prior art, the method can be applied to a large number of functional groups, the yield is high, the number of by-products is small, and the method is easy to operate, safe, low in cost and environmentally friendly. (Please see the specifications for the formula).
- -
-
Paragraph 0058
(2019/03/08)
-
- Method used for rapid preparation of benzo-heterocycle compound with physical grinding under solvent-free room temperature conditions
-
The invention discloses a method used for rapid preparation of benzo-heterocycle compound with physical grinding under solvent-free room temperature conditions. According to the method, glacial aceticacid is taken as a catalyst; at solvent-free room temperature conditions, physical grinding is adopted, reaction of 2-substituted arylamines (2-mercapto arylamine, 2-aminophenol, and o-phenylenediamine) and aromatic aldehydes is carried out using physical grinding. The method is friendly to the environment, is simple in operation, is safe, is low in cost, and is high in efficiency. Compared withthe prior art, the advantages are that: the method is suitable for a large amount of functional groups, yield is high, less by-product is generated, operation is simple, the method is safe, cost is low, and the method is friendly to the environment.
- -
-
Paragraph 0062; 0089
(2019/01/21)
-
- Oxidative NHC Catalysis for the Generation of Imidoyl Azoliums: Synthesis of Benzoxazoles
-
N-Heterocyclic carbene (NHC)-catalyzed intramolecular cyclization of aldimines generated from 2-amino phenols and aromatic aldehydes leading to the synthesis of 2-arylbenzoxazoles under mild conditions is presented. The reaction proceeds via the generation of the aza-Breslow intermediates from imines and NHC, which under oxidative conditions form the key imidoyl azoliums and a subsequent intramolecular cyclization furnishes the product. The reaction tolerates a broad range of functional groups, and the products are formed in generally good yields.
- Patra, Atanu,James, Anjima,Das, Tamal Kanti,Biju, Akkattu T.
-
p. 14820 - 14826
(2019/01/03)
-
- Deep eutectic solvent-catalyzed arylation of benzoxazoles with aromatic aldehydes
-
A novel and efficient methodology for the arylation of benzoxazoles with aromatic aldehydes catalyzed by deep eutectic solvent has been developed. The reaction smoothly proceeded with a wide range of substrates to give the desired products in high yields within short reaction time. Deep eutectic solvents are easily recovered and reused without significant loss of catalytic activity.
- Tran, Phuong Hoang,Thi Hang, Anh-Hung
-
p. 11127 - 11133
(2018/03/26)
-
- Synthesis and characterization of amino glucose-functionalized silica-coated NiFe2O4 nanoparticles: A heterogeneous, new and magnetically separable catalyst for the solvent-free synthesis of 2,4,5–trisubstituted imidazoles, benzo[d]imidazoles, benzo[d] oxazoles and azo-linked benzo[d]oxazoles
-
Amino glucose-functionalized silica-coated NiFe2O4 nanoparticles (NiFe2O4@SiO2@amino glucose) were chemically synthesized and characterized by transmission electron microscope (TEM), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), energy dispersive X-ray analysis (EDX), vibrating sample magnetometer (VSM), Zetasizer and Fourier transform infrared spectroscopy (FT-IR) instruments. NiFe2O4@SiO2@amino glucose supply an environmentally friendly procedure for the synthesis of 2,4,5-trisubstituted imidazoles through one-pot multicomponent condensation of benzil or benzoin, ammonium acetate with aryl aldehydes and for the synthesis of benzoxazoles using condensation reaction of 2-aminophenol with aryl aldehydes under solvent free condition. In the other study, this synthesized magnetically reusable catalyst was introduced as a new avenue for the synthesis of benzo[d]imidazoles using the reaction between aryl aldehydes and 1,2-diaminobenzene. These compounds were obtained in high yields and short reaction times. The catalyst could be easily recovered and reused for five cycles with almost consistent activity. Synthesized compounds were characterized by their physical constant, comparison with authentic samples, FT-IR, 1H NMR, 13C NMR spectroscopy and elemental analysis.
- Fekri, Leila Zare,Nikpassand, Mohammad,Shariati, Shahab,Aghazadeh, Behnaz,Zarkeshvari, Reza,Norouz pour, Nahid
-
-
- Phosphonium acidic ionic liquid: An efficient and recyclable homogeneous catalyst for the synthesis of 2-Arylbenzoxazoles, 2-Arylbenzimidazoles, and 2-Arylbenzothiazoles
-
A highly efficient and green strategy for the synthesis of 2-Arylbenzoxazoles, 2-Arylbenzimidazoles, and 2-Arylbenzothiazoles catalyzed by phosphonium acidic ionic liquid has been developed via the condensation of o-Aminophenol, o-phenylenediamines, and o-Aminothiophenol, respectively, with aldehydes. The reaction has a good yield, the broad substrate scope, and mild condition. Triphenyl(butyl-3-sulphonyl)phosphonium toluenesulfonate catalyst was easily obtained from cheap and available starting materials through a one-pot synthesis. Its structure was identified by 1H NMR, 13C NMR, 31P NMR, and FT-IR techniques. Other properties including thermal stability and acidity were determined by TGA and Hammett acidity function method. Interestingly, the catalyst can maintain its constantly outstanding performance till the fourth recovery.
- Nguyen, Quang The,Thi Hang, Anh-Hung,Ho Nguyen, Thuy-Linh,Nguyen Chau, Duy-Khiem,Tran, Phuong Hoang
-
p. 11834 - 11842
(2018/04/05)
-
- S8-Mediated Cyclization of 2-Aminophenols/thiophenols with Arylmethyl Chloride: Approach to Benzoxazoles and Benzothiazoles
-
A metal-free approach to benzazoles from arylmethyl chlorides and 2-mercaptan/2-hydroxyanilines using elemental sulfur as a traceless oxidizing agent has been developed. The reactions proceeded in good to excellent yields, exhibiting good functional groups tolerance and gram-scale ability. A key mechanistic investigation indicated that the key intermediate trisulfide 6, which was characterized by NMR, HRMS and crystal X-ray crystallography, was separated in the reaction prior to the formation of the product.
- Gan, Haifeng,Miao, Dazhuang,Pan, Qiang,Hu, Renhe,Li, Xiaotong,Han, Shiqing
-
supporting information
p. 1770 - 1774
(2016/07/07)
-
- A mild, efficient and reusable solid phosphotungestic acid catalyst mediated synthesis of benzoxazole derivatives: A grinding approach
-
Background: The development of efficient methodologies for the preparation of benzoxazole and its derivatives has gained a lot of importance in current research. There are many methods are reported for the synthesis of benzoxazoles includes condensation of 2-aminophenol with carboxylic acid. Traditional methods also have several side reactions, non renewable oxidative reagents and solvents which negatively affect the environmentally and eco-friendly nature of the reaction. We have developed PTA catalyzed synthesis of 2-arylbenzoxazole from 2-aminophenols with different aromatic aldehydes using a grinding strategy in excellent yield. Methods: The synthesis of benzoxazoles in high yields by using silica supported Rangappa S. Keri PTA/PTA as solid acid catalyst at room temperature using grinding method. Results: Aromatic aldehydes which have electron donating or electron withdrawing groups were also investigated and as expected it gives good to excellent yield of products, it can be seen that electron donating and electron withdrawing groups does not show any difference on their action yields. Conclusion: We have developed PTA catalyzed synthesis of 2-arylbenzoxazole from 2-aminophenols with different aromatic aldehydes using a grinding strategy in excellent yield. The use of this reusable catalyst under solvent-free conditions has made this protocol practical, environmentally friendly and economically attractive. The simple work-up procedure, the short reaction times the mild reaction conditions, the high yields of products and the non-toxicity of the catalyst are other advantages of the present method. This protocol approaches combines the advantages of both focused library synthesis and diversity oriented synthesis because of the simplification of reaction protocol that we have been developed.
- Patil, Mahadeo R.,Yelamaggad, Aditya,Keri, Rangappa S.
-
p. 474 - 481
(2016/11/19)
-
- Palladium catalyzed Csp2-H activation for direct aryl hydroxylation: The unprecedented role of 1,4-dioxane as a source of hydroxyl radicals
-
A novel strategy for direct aryl hydroxylation via Pd-catalysed Csp2-H activation through an unprecedented hydroxyl radical transfer from 1,4-dioxane, used as a solvent, is reported with bio relevant and sterically hindered heterocycles and various acyclic functionalities as versatile directing groups.
- Seth, Kapileswar,Nautiyal, Manesh,Purohit, Priyank,Parikh, Naisargee,Chakraborti, Asit K.
-
p. 191 - 194
(2015/01/09)
-
- Synthesis of 2-arylbenzoxazoles through oxidation of C-H bonds adjacent to oxygen atoms
-
A practical and simple synthesis of benzoxazoles from easily available substrates was developed. The protocol is triggered by an iron-catalyzed tandem oxidative process from simple ether derivatives. A practical and simple synthesis of benzoxazoles from easily available substrates is developed. The protocol is triggered by an iron-catalyzed tandem oxidative process from simple ether derivatives. Copyright
- Gu, Lijun,Wang, Wei,Xiong, Yong,Huang, Xiangzhong,Li, Ganpeng
-
p. 319 - 322
(2014/01/23)
-
- Synthesis of 2-Arylbenzoxazoles through Oxidation of C-H Bonds Adjacent to Oxygen Atoms
-
A practical and simple synthesis of benzoxazoles from easily available substrates was developed. The protocol is triggered by an iron-catalyzed tandem oxidative process from simple ether derivatives.
- Gu, Lijun,Wang, Wei,Xiong, Yong,Huang, Xiangzhong,Li, Ganpeng
-
p. 319 - 322
(2015/10/05)
-
- Tri-lacunary polyoxometalates of Na8H[PW9O 34] as heterogeneous Lewis base catalysts for Knoevenagel condensation, cyanosilylation and the synthesis of benzoxazole derivatives
-
We reported for the first time the development of tri-lacunary polyoxometalates (POMs) of Na8H[A-PW9O34] ·7H2O and Na8H[B-PW9O 34]·19H2O (Na-A-PW9 and Na-B-PW 9) as highly selective and efficient heterogeneous Lewis base catalysts for Knoevenagel condensation, cyanosilylation of various aldehydes and ketones and the synthesis of benzoxazole derivatives at 25 C under mild conditions. Since both Na-A-PW9 and Na-B-PW9 display no characteristic porosity, it is proposed that the catalytic reactions proceed not only on the surface and interface, but also in the bulk phase. The catalysts can be easily recovered and reused for at least six times without obvious decrease of catalytic activities and the structures of the catalysts remain unchanged after recycling. The easy preparation, high efficiency, reusability of the heterogeneous catalysts of Na-A-PW9 and Na-B-PW9 exhibit great potential for further application.
- Zhao, Shen,Chen, Yang,Song, Yu-Fei
-
p. 140 - 146
(2014/03/21)
-
- Mesoporous poly(melamine-formaldehyde): A green and recyclable heterogeneous organocatalyst for the synthesis of benzoxazoles and benzothiazoles using dioxygen as oxidant
-
A simple, highly efficient, and sustainable strategy for the synthesis of benzoxazole and benzothiazole derivatives was developed by using inexpensive, green, readily available, and recyclable mesoporous poly(melamine-formaldehyde) as a green, heterogeneous organocatalyst. The corresponding substituted benzoxazoles and benzothiazoles were obtained in good to excellent yields by aerobic oxidation of o-substituted aminobenzenes with various aldehydes under dioxygen atmosphere. The catalyst can be completely recovered through simple filtration to be reused more than six times without significant loss of catalytic activity.
- Yang, Daoshan,Liu, Peng,Zhang, Ning,Wei, Wei,Yue, Mingbo,You, Jinmao,Wang, Hua
-
p. 3434 - 3439
(2015/04/16)
-
- A novel strategy for the construction of substituted benzoxazoles via a tandem oxidative process
-
A practical and simple synthesis of benzoxazoles from easily available substrates was developed. The protocol is triggered by an iron-catalyzed tandem oxidative process from simple toluene derivatives and 2-aminophenols. This method represents a straightforward approach to access substituted benzoxazoles. This journal is The Royal Society of Chemistry 2013.
- Gu, Lijun,Jin, Cheng,Guo, Junming,Zhang, Lizhu,Wang, Wei
-
supporting information
p. 10968 - 10970
(2013/11/19)
-
- Nano ceria catalyzed synthesis of substituted benzimidazole, benzothiazole, and benzoxazole in aqueous media
-
A series of substituted benzimidazoles, benzothiazoles, and benzoxazoles was synthesized by combining 1,2-phenylenediamine, 2-aminothiophenol, or 2-aminophenol with aryl, heteroaryl, aliphatic, α,β-unsaturated aldehydes in the presence of nano ceria (CeO2) as an efficient heterogeneous catalyst.
- Shelkar, Radheshyam,Sarode, Sachin,Nagarkar, Jayashree
-
supporting information
p. 6986 - 6990
(2013/12/04)
-
- COMPOUNDS FOR POROUS FILMS IN LIGHT-EMITTING DEVICES
-
Compounds useful in porous films for light extraction and/or light scattering in electronic devices, such as light-emitting devices, are described herein. These compounds may be represented by Formula 1, as described herein. [in-line-formulae]Rg5-Rg3-Rg1-Rg2-Rg4??(Formula 1)[/in-line-formulae]
- -
-
Page/Page column 22
(2012/09/11)
-
- TRIS(ARYLBENZOXAZOLE)BENZENE AND TRIS(ARYLBENZTHIAZOLE)BENZENE AND DERIVATIVES THEREOF AS ORGANIC ELECTRON-TRANSPORT MATERIALS
-
A compound represented by a Formula 1: wherein Ph1, Ar1, Ar2, Ar3 Bz1, Bz2, and Bz3 are described herein. Light-emitting devices containing the compound of Formula are also described herein.
- -
-
Page/Page column 7; 9
(2011/08/22)
-
- Copper-mediated synthesis of substituted 2-aryl-N-benzylbenzimidazoles and 2-arylbenzoxazoles via C-H functionalization/C-N/C-O bond formation
-
An efficient method for the transformation of N-benzyl bisarylhydrazones and bisaryloxime ethers to functionalized 2-aryl-N-benzylbenzimidazoles and 2-arylbenzoxazoles is described. The protocol involves a copper(II)-mediated cascade C-H functionalization/C-N/C-O bond formation under neutral conditions. Substrates having either electron-donating or -withdrawing substituents undergo the cyclization to afford the target heterocycles at moderate temperature.
- Guru, Murali Mohan,Ali, Md Ashif,Punniyamurthy, Tharmalingam
-
p. 5295 - 5308
(2011/08/05)
-
- Copper(II)-catalyzed conversion of bisaryloxime ethers to 2-arylbenzoxazoles via C-H functionalization/C-N/C-O bonds formation
-
A copper(II)-catalyzed conversion of bisaryloxime ethers to 2-arylbenzoxazoles has been developed. The reaction involves a cascade C-H functionalization and C-N/C-O bond formation under oxygen atmosphere.(Figure Presented)
- Guru, Murali Mohan,Ali, Md Ashif,Punniyamurthy, Tharmalingam
-
supporting information; experimental part
p. 1194 - 1197
(2011/04/26)
-
- An efficient synthesis of 2-substituted benzoxazoles via RuCl 3·3H2O catalyzed tandem reactions in ionic liquid
-
An efficient synthesis of 2-substituted benzoxazoles through RuCl 3·3H2O catalyzed, air oxidized tandem reactions of 2-aminophenols and aldehydes in [bmim]BF4 was developed. This synthetic strategy has such advantages as mild reaction conditions, cost-free oxidant, readily available starting materials, and recyclable catalyst and solvent. As an application, it was successfully used in the synthesis of the unreported 5-(benzoxazol-2-yl)-2′-deoxyuridines with potential biological activities. A novel and efficient synthesis of 2-substituted benzoxazoles through RuCl3 catalyzed, air oxidized tandem reactions of 2-aminophenols and aldehydes in [bmim]BF4 was developed.
- Fan, Xuesen,He, Yan,Wang, Yangyang,Zhang, Xinying,Wang, Jianji
-
experimental part
p. 773 - 777
(2011/11/12)
-
- Chlorination and ortho-acetoxylation of 2-arylbenzoxazoles
-
Efficient and facile catalytic protocols for chlorination and ligand-directed ortho-acetoxylation of 2-arylbenzoxazoles have been developed. The chlorination is not a ligand-directed ortho-functionalization, but an electrophilic substitution process in the benzo ring of the benzoxazole moiety. Meanwhile, the acetoxylation exhibited high regioselectivity for the substrates containing a meta-substituent and occurred at the less sterically hindered ortho-C-H bond of the directing group. The Royal Society of Chemistry 2011.
- Leng, Yuting,Yang, Fan,Zhu, Weiguo,Wu, Yangjie,Li, Xiang
-
supporting information; experimental part
p. 5288 - 5296
(2011/08/05)
-
- Cobalt-catalyzed intramolecular C-N and C-O cross-coupling reactions: Synthesis of benzimidazoles and benzoxazoles
-
Cobalt(ii)-complex catalyzes efficiently the intramolecular C-N and C-O cross-couplings of Z-N′-(2-halophenyl)-N-phenylamidines and N-(2-bromophenyl)benzamides to afford the corresponding substituted benzimidazoles and benzoxazoles in the presence of K2CO3 at moderate temperature. The protocol is general, air stable and affords the products selectively in moderate to high yield.
- Saha, Prasenjit,Ali, Md Ashif,Ghosh, Pokhraj,Punniyamurthy, Tharmalingam
-
experimental part
p. 5692 - 5699
(2011/02/18)
-
- Synthesis of benzoxazoles by an efficient ullmann-type intramolecular CO bond-forming coupling cyclization with a BINAM-copper(II) catalyst
-
A wide range of 2-substituted benzoxazoles were synthesized from the corresponding N-(2-iodophenyl)benzamides through intramolecular CO bond formation via Ullmann-type coupling cyclization in the presence of a catalytic amount of an easily available BINAM-copper(II) complex under very mild reaction conditions (82C). Less reactive bromo and chloro analogues of the N-(2-halophenyl)benzamides were also successfully cyclized to produce benzoxazoles, without increasing the catalyst loading. Georg Thieme Verlag Stuttgart · New York.
- Naidu, Ajay B.,Sekar, Govindasamy
-
experimental part
p. 579 - 586
(2010/04/05)
-
- Ligand-free copper-catalyzed synthesis of substituted benzimidazoles, 2-aminobenzimidazoles, 2-aminobenzothiazoles, and benzoxazoles
-
(Chemical Equation Presented) The synthesis of substituted benzimidazoles, 2-aminobenzimidazoles, 2-aminobenzothiazoles, and benzoxazoles is described via intramolecular cyclization of o-bromoaryl derivatives using copper(II) oxide nanoparticles in DMSO under air. The procedure is experimentally simple, general, efficient, and free from addition of external chelating ligands. It is a heterogeneous process and the copper(II) oxide nanoparticles can be recovered and recycled without loss of activity. 2009 American Chemical Society.
- Saha, Prasenjit,Ramana, Tamminana,Purkait, Nibadita,Ali, Md. Ashif,Paul, Rajesh,Punniyamurthy, Tharmalingam
-
supporting information; experimental part
p. 8719 - 8725
(2010/02/28)
-
- Direct ortho-arylation of 2-arylbenzoxazoles via C-H activation
-
A new and highly regioselective arylation of 2-arylbenzoxazoles based on C-H activation has been developed. The results represent the first examples of palladium-catalyzed direct ortho-arylation of 2-arylbenzoxazoles and also provide a facile route for the synthesis of complicated structures containing arylated benzoxazoles moieties.
- Yang, Fan,Wu, Yangjie,Zhu, Zhiwu,Zhang, Junli,Li, Yanan
-
p. 6782 - 6787
(2008/12/20)
-
- Biochemical and structural evaluation of highly selective 2-arylbenzoxazole-based transthyretin amyloidogenesis inhibitors
-
To develop potent transthyretin (TTR) amyloidogenesis inhibitors that also display high binding selectivity in blood, it proves useful to systematically optimize each of the three substructural elements that comprise a typical inhibitor: the two aryl rings and the linker joining them. In the first study, described herein, structural modifications to one aryl ring were evaluated by screening a library of 2-arylbenzoxazoles bearing thyroid hormone-like aryl substituents on the 2-aryl ring. Several potent and highly selective amyloidogenesis inhibitors were identified that exhibit minimal thyroid hormone nuclear receptor and COX-1 binding. High resolution crystal structures (1.3-1.5 ?) of three inhibitors (2f, 4f, and 4d) in complex with TTR were obtained to characterize their binding orientation. Collectively, the results demonstrate that thyroid hormone-like substitution patterns on one aryl ring lead to potent and highly selective TTR amyloidogenesis inhibitors that lack undesirable thyroid hormone receptor or COX-1 binding.
- Johnson, Steven M.,Connelly, Stephen,Wilson, Ian A.,Kelly, Jeffery W.
-
p. 260 - 270
(2008/09/18)
-