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?.
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.
Iron(III) Chloride Mediated para-Selective C-H Functionalization: Access to C5-Chloro and C5,C7-Dichloro/Dianisyl Substituted 2-Arylbenzoxazoles
Panda, Niranjan,Sahoo, Kanchanbala
supporting information, (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
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.
Electrochemical Generation of Hypervalent Bromine(III) Compounds
Francke, Robert,Mohebbati, Nayereh,Sokolovs, Igors,Suna, Edgars
supporting information, p. 15832 - 15837 (2021/06/14)
In sharp contrast to hypervalent iodine(III) compounds, the isoelectronic bromine(III) counterparts have been little studied to date. This knowledge gap is mainly attributed to the difficult-to-control reactivity of λ3-bromanes as well as to their challenging preparation from the highly toxic and corrosive BrF3 precursor. In this context, we present a straightforward and scalable approach to chelation-stabilized λ3-bromanes by anodic oxidation of parent aryl bromides possessing two coordinating hexafluoro-2-hydroxypropanyl substituents. A series of para-substituted λ3-bromanes with remarkably high redox potentials spanning a range from 1.86 V to 2.60 V vs. Ag/AgNO3 was synthesized by the electrochemical method. We demonstrate that the intrinsic reactivity of the bench-stable bromine(III) species can be unlocked by addition of a Lewis or a Br?nsted acid. The synthetic utility of the λ3-bromane activation is exemplified by oxidative C?C, C?N, and C?O bond forming reactions.
