833-50-1Relevant academic research and scientific papers
Mechanistic study of chemoselectivity in ni-catalyzed coupling reactions between azoles and aryl carboxylates
Lu, Qianqian,Yu, Haizhu,Fu, Yao
, p. 8252 - 8260 (2014)
Itami et al. recently reported the C-O electrophile-controlled chemoselectivity of Ni-catalyzed coupling reactions between azoles and esters: the decarbonylative C-H coupling product was generated with the aryl ester substrates, while C-H/C-O coupling pro
A multistep flow process for the synthesis of highly functionalized benzoxazoles
Sedelmeier, Joerg,Lima, Fabio,Litzler, Alain,Martin, Benjamin,Venturoni, Francesco
, p. 5546 - 5549 (2013)
An efficient and scalable transformation of 3-halo-N-acyl anilines to the corresponding benzoxazoles within a continuous flow reactor is reported. This transformation proceeds via base-mediated deprotonation, ortho-lithiation, and intramolecular cyclization to provide unstable lithiated benzoxazole moieties. The subsequent in-line electrophilic quench results in the formation of substituted benzoxazoles in high yield and quality. Continuous flow technology allowed for accurate temperature control and immediate in-line quench while minimizing the hold-up time for the unstable lithiated intermediates thereby minimizing associated byproduct formation.
Synthesis of 4-Alkenyl Benzoxazoles via Pd-catalyzed ortho C?H Functionalization of 2-Amidophenols
Panda, Niranjan,Sahoo, Kanchanbala
, p. 617 - 627 (2019)
A one-pot direct transformation to remotely C?H alkene functionalized 2-aryl benzoxazoles from the reaction of amidophenol and electronically deficient olefin was reported. Control experiments confirm that the Pd-catalyzed regioselective C?H activation/alkenylation occurs at the first step by leading to ortho-alkenylated amidophenol; which subsequently underwent tandem intramolecular annulation to afford C4-alkenylated 2-arylbenzoxazole derivatives. (Figure presented.).
A key role for iodobenzene in the direct C-H bond functionalisation of benzoxazoles using PhI(OAc)2 mediated by a Pd(OAc) 2/1,10-phenanthroline catalyst system: In situ formation of well-defined Pd nanoparticles
Williams, Thomas J.,Fairlamb, Ian J.S.
, p. 2906 - 2908 (2013)
PhI(OAc)2 has previously been reported as a reagent for the direct arylation of C-H bonds in benzoxazole in a PdII/IV-mediated process. However, evidence reported here suggests this reagent degrades to iodobenzene under the literature reported reaction conditions. Further, we present evidence for the rapid formation of Pd0 nanoparticles in this reaction, leading us to question what is the active catalytic Pd phase in coupling chemistry?.
Iron(III) Chloride Mediated para-Selective C-H Functionalization: Access to C5-Chloro and C5,C7-Dichloro/Dianisyl Substituted 2-Arylbenzoxazoles
Sahoo, Kanchanbala,Panda, Niranjan
, p. 1023 - 1030 (2022/02/03)
Iron(III) chloride mediated para-selective C?H chlorination and subsequent annulation of 2-amidophenol to synthesize C5- and C5, C7-chlorinated benzoxazoles was developed. Further, the oxidative cross-dehydrogenative coupling of amidophenol with anisole b
DMF-Assisted Radical Cyclization of o-Isocyanodiaryl Ethers via 1,5-Aryl Migration: Construction of 2-Arylbenzoxazoles
Cai, Jingyu,Ding, Qiuping,Peng, Yiyuan,Song, Zhibin,Tan, Yuxing,Ye, Xiaoling,Yuan, Sitian
, p. 1485 - 1492 (2022/01/20)
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.
Novel and efficient heterogeneous polymer supported copper catalyst for synthesis of 2-substituted Benzoxazoles from 2-Haloanilides
Saranya, Thachora Venu,Sruthi, Pambingal Rajan,Raj, Veena,Anas, Saithalavi
supporting information, (2021/02/27)
A novel polymer supported copper complex is prepared by the immobilization of copper iodide on chemically modified polyacrylonitrile and its application in heterogeneous catalysis is described. The catalyst was prepared by easy method via synthetic modification of Polyacrylonitrile (PAN) using ethylene diamine followed by the complexation with CuI. After characterization, this complex was explored as a green and efficient heterogeneous catalyst for the synthesis of 2-benzoxazoles from 2-haloanilides. The reaction was performed without adding additional ligand and the catalyst shows activity over a broad range of substrates with quantitative product yields. The catalyst was easily recovered by simple filtration and reused successfully for further cycle.
Copper-catalyzed regioselective 2-amination of o-haloanilides with aqueous ammonia
Tang, Yan-Ling,Li, Mei-Ling,Gao, Jin-Chun,Sun, Yun,Qu, Lu,Huang, Feng,Mao, Ze-Wei
, (2021/04/02)
An efficient Cu(II)-vasicine catalytic system has been developed for intramolecular C[sbnd]N bond formation. In this way, regioselective 2-amination of o-haloanilides with aqueous ammonia in EtOH has been achieved. This strategy provides several advantages, such as good regioselectivity, high yields and functional group tolerance.
Exploration of Cu-catalyzed regioselective hydrodehalogenation of o-haloanilides using EtOH as hydrogen source
Li, Min-Xin,Li, Mei-Ling,Tang, Yan-Ling,Sun, Yun,Qu, Lu,Huang, Feng,Mao, Ze-Wei
supporting information, (2021/05/03)
In present work, we have explored a Cu(acac)2/vasicine-catalyzed regioselective hydrodehalogenation methodology of o-haloanilides using EtOH as hydrogen source and solvent. The catalytic system could selectively dehalogenate 2-Br and 2-I, and features regioselective, efficient and functional group tolerance.
UV-visible light-induced photochemical synthesis of benzimidazoles by coomassie brilliant blue coated on W-ZnO@NH2nanoparticles
Chen, Ruijuan,Jalili, Zahra,Tayebee, Reza
, p. 16359 - 16375 (2021/05/19)
Heterogeneous photocatalysts proffer a promising method to actualize eco-friendly and green organic transformations. Herein, a new photochemical-based methodology is disclosed in the preparation of a wide range of benzimidazoles through condensation of o-phenylenediamine with benzyl alcohols in the air under the illumination of an HP mercury lamp in the absence of any oxidizing species catalyzed by a new photocatalyst W-ZnO@NH2-CBB. In this photocatalyst, coomassie brilliant blue (CBB) is heterogenized onto W-ZnO@NH2 to improve the surface characteristics at the molecular level and enhance the photocatalytic activity of both W-ZnO@NH2 and CBB fragments. This unprecedented heterogeneous nanocatalyst is also identified by means of XRD, FT-IR, EDS, TGA-DTG, and SEM. The impact of some influencing parameters on the synthesis route and effects on the catalytic efficacy of W-ZnO@NH2-CBB are also assessed. The appropriate products are attained for both the electron-withdrawing and electron-donating substituents in the utilized aromatic alcohols. Furthermore, preparation of benzimidazoles is demonstrated to occur mainly via a radical mechanism, which shows that reactive species such as ·O2-, OH and h+ would be involved in the photocatalytic process. Stability and reusability studies also warrant good reproducibility of the nanophotocatalyst for at least five runs. Eventually, a hot filtration test proved that the nanohybrid photocatalyst is stable in the reaction medium. Using an inexpensive catalyst, UV-vis light energy and air, as a low cost and plentiful oxidant, puts this methodology in the green chemistry domain and energy-saving organic synthesis strategies. Finally, the anticancer activity of W-ZnO nanoparticles is investigated on MCF7 breast cancer cells by MTT assay. This experiment reveals that the mentioned nanoparticles have significant cytotoxicity towards the selected cell line.
