1
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Abdullah Al Awadh A. Biomedical applications of selective metal complexes of indole, benzimidazole, benzothiazole and benzoxazole: A review (From 2015 to 2022). Saudi Pharm J 2023; 31:101698. [PMID: 37533494 PMCID: PMC10393588 DOI: 10.1016/j.jsps.2023.101698] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 07/04/2023] [Indexed: 08/04/2023] Open
Abstract
Indole, benzoxazole benzothiazole and benzimidazole are excellent classes of organic heterocyclic compounds. These compounds show significant application in pharmacy, industries, dyes, medicine, polymers and food packages. These compounds also form metal complexes with copper, zinc, cadmium, nickel, cobalt, platinum, gold, palladium chromium, silver, iron, and other metals that have shown to be significant applications. Recently, researchers have attracted enormous attention toward heterocyclic compounds such as indole, benzimidazole, benzothiazole, benzoxazole, and their complexes due to their excellent medicinal applications such as anti-ulcerogenic, anti-cancer, antihypertensive, antifungal, anti-inflammatory, antitubercular, antiparasitic, anti-obesity, antimalarial, antiglycation, antiviral potency, antineuropathic, analgesic antioxidant, antihistaminic, and antibacterial potentials. In this article, we summarize the medicinal applications of these compounds as well as their metal complexes. We hope this article will help researchers in designing and synthesizing novel and potent compounds with significant applications in various fields.
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2
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Kumar S, Kajol K, Nayak P, Kumar A, Ramesh C. Synthesis of tetracyclic 4H-benzo[5,6]chromeno[3,4-d]oxazoles via palladium-catalyzed intramolecular direct heteroarylation. Chem Asian J 2023; 18:e202201151. [PMID: 36519340 DOI: 10.1002/asia.202201151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022]
Abstract
We report a palladium-catalyzed intramolecular direct heteroarylation of oxazole tethered β-naphthols to access corresponding tetracyclic 4H-benzo[5,6]chromeno[3,4-d]oxazoles. Various functional groups are well tolerated and furnished the desired products in good to excellent yields under the present reaction conditions. The scale-up reaction and synthetic utility of the resulting molecules have been demonstrated. Moreover, UV/vis absorption and fluorescence emission properties have been evaluated for these polyheterocyclic compounds.
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Affiliation(s)
- Sujeet Kumar
- Medicinal & Process Chemistry Division, CSIR-Central Drug Research Institute BS-10/1, Sector 10 Jankipuram extension, Sitapur Road, P.O. Box 173, Lucknow, 226031, India.,Academy of Scientific and Innovative Research, New Delhi, 110001, India
| | - Km Kajol
- Medicinal & Process Chemistry Division, CSIR-Central Drug Research Institute BS-10/1, Sector 10 Jankipuram extension, Sitapur Road, P.O. Box 173, Lucknow, 226031, India
| | - Prakash Nayak
- School of Chemical Sciences National Institute of Science Education and Research (NISER), Bhubaneswar, HBNI, Bhubaneswar, 752050, Odisha, India
| | - Amit Kumar
- Medicinal & Process Chemistry Division, CSIR-Central Drug Research Institute BS-10/1, Sector 10 Jankipuram extension, Sitapur Road, P.O. Box 173, Lucknow, 226031, India.,Academy of Scientific and Innovative Research, New Delhi, 110001, India
| | - Chintakunta Ramesh
- Medicinal & Process Chemistry Division, CSIR-Central Drug Research Institute BS-10/1, Sector 10 Jankipuram extension, Sitapur Road, P.O. Box 173, Lucknow, 226031, India.,Academy of Scientific and Innovative Research, New Delhi, 110001, India
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3
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Peng L, Hu Z, Zhao Y, Peng L, Xu Z, Yin SF, Tang Z, Qiu R, Kambe N. One-pot synthesis of phosphorylnaphth[2,1- d]oxazoles and products as P,N-ligands in C-N and C-C formation. Org Biomol Chem 2022; 20:4110-4114. [PMID: 35551357 DOI: 10.1039/d2ob00565d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Phosphanylnaphtho[2,1-d]oxazoles were synthesized successfully through one-pot phosphonation of naphthoquinone with diaryl(alkyl)phosphine oxides and Cu-catalyzed oxidative condensation with imines, followed by methylation and reduction. Upon applying 4-phosphanylnaphtho[2,1-d]oxazole as a P,N-chelating ligand, Pd-catalyzed C-N formation of amines or nitrobenzene as well as Ni-catalyzed C-C formation and the synthesis of quinoline proceeded successfully. The reaction was facilely scaled up to give N-benzylaniline 15a in a gram scale synthesis. This research provided a facile and convenient protocol to synthesize phosphanylnaphtho[2,1-d]oxazoles, which could be applied as an efficient P,N-ligand in transition-metal-catalyzed C-N and C-C formation to produce the desired products in high yields with wide functional group tolerance under small catalyst loading, solvent-free conditions in many reactions.
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Affiliation(s)
- Lingteng Peng
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China.
| | - Zhifang Hu
- Key Laboratory of Theoretical Organic Chemistry and Functional Molecule of Ministry of Education, Hunan Provincial Key Laboratory of Controllable Preparation and Functional Application of Fine Polymers, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, P. R. China
| | - Yanting Zhao
- Key Laboratory of Theoretical Organic Chemistry and Functional Molecule of Ministry of Education, Hunan Provincial Key Laboratory of Controllable Preparation and Functional Application of Fine Polymers, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, P. R. China
| | - Lifen Peng
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China. .,Key Laboratory of Theoretical Organic Chemistry and Functional Molecule of Ministry of Education, Hunan Provincial Key Laboratory of Controllable Preparation and Functional Application of Fine Polymers, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, P. R. China
| | - Zhi Xu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China.
| | - Shuang-Feng Yin
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China.
| | - Zilong Tang
- Key Laboratory of Theoretical Organic Chemistry and Functional Molecule of Ministry of Education, Hunan Provincial Key Laboratory of Controllable Preparation and Functional Application of Fine Polymers, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, P. R. China
| | - Renhua Qiu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China.
| | - Nobuaki Kambe
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China. .,Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan.
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4
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Wu S, Geng F, Dong J, Liu L, Su L, Zhou Y. General and practical synthesis of naphtho[2,1-d]oxazoles from naphthols and amines. Org Chem Front 2022. [DOI: 10.1039/d2qo00557c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A general and practical synthesis of naphtho[2,1-d]oxazoles from readily available naphthols and amines is developed using TEMPO as the oxygen source with outstanding functional group tolerance, especially for the construction...
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5
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Abstract
A Cu-catalyzed straightforward synthesis of benzoxazoles from free phenols and cyclic oxime esters is reported. The mild reaction conditions tolerate various electron-withdrawing and electron-donating functional groups on both substrates, affording benzoxazoles in moderate to good yields. With this protocol, large-scale syntheses of Ezutromid and Flunoxaprofe in one or two steps are demonstrated. A catalytic mechanism, which includes Cu-catalyzed amination via inner-sphere electron transfer and consequent annulation, is proposed.
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Affiliation(s)
- Zheng-Hai Wang
- Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules, University of Chinese Academy of Sciences, Shanghai Institute of Organic Chemistry, CAS, 345 Lingling Road, Shanghai 200032, China
| | - Dong-Hui Wang
- Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules, University of Chinese Academy of Sciences, Shanghai Institute of Organic Chemistry, CAS, 345 Lingling Road, Shanghai 200032, China.,Department of Pharmacy, Nanjing University of Chinese Medicine, 138 Xianlin Boulevard, Nanjing 210023, China
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6
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Chen F, Zhu C, Yang Z, Liu C, Zeng H, Wu W, Jiang H. C–H Amination Enabled [2+1+1+1] Annulation Reaction in Water: Access to Benzoxazoles. European J Org Chem 2021. [DOI: 10.1002/ejoc.202100942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Fulin Chen
- Key Laboratory of Functional Molecular Engineering of Guangdong Province School of Chemistry and Chemical Engineering South China University of Technology Guangzhou 510640 P. R. China
| | - Chuanle Zhu
- Key Laboratory of Functional Molecular Engineering of Guangdong Province School of Chemistry and Chemical Engineering South China University of Technology Guangzhou 510640 P. R. China
| | - Zhiyi Yang
- Key Laboratory of Functional Molecular Engineering of Guangdong Province School of Chemistry and Chemical Engineering South China University of Technology Guangzhou 510640 P. R. China
| | - Chi Liu
- Key Laboratory of Functional Molecular Engineering of Guangdong Province School of Chemistry and Chemical Engineering South China University of Technology Guangzhou 510640 P. R. China
| | - Hao Zeng
- Key Laboratory of Functional Molecular Engineering of Guangdong Province School of Chemistry and Chemical Engineering South China University of Technology Guangzhou 510640 P. R. China
| | - Wanqing Wu
- Key Laboratory of Functional Molecular Engineering of Guangdong Province School of Chemistry and Chemical Engineering South China University of Technology Guangzhou 510640 P. R. China
| | - Huanfeng Jiang
- Key Laboratory of Functional Molecular Engineering of Guangdong Province School of Chemistry and Chemical Engineering South China University of Technology Guangzhou 510640 P. R. China
- State Key Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 730000 P. R. China
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7
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Chen F, Zhu C, Jiang H. [3+1+1] Annulation Reaction of Benzo‐1,2‐Quinones, Aldehydes and Hydroxylamine Hydrochloride: Access to Benzoxazoles with Inorganic Nitrogen Source. Adv Synth Catal 2021. [DOI: 10.1002/adsc.202001521] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Fulin Chen
- Key Laboratory of Functional Molecular Engineering of Guangdong Province School of Chemistry and Chemical Engineering South China University of Technology Guangzhou 510640 People's Republic of China
| | - Chuanle Zhu
- Key Laboratory of Functional Molecular Engineering of Guangdong Province School of Chemistry and Chemical Engineering South China University of Technology Guangzhou 510640 People's Republic of China
| | - Huanfeng Jiang
- Key Laboratory of Functional Molecular Engineering of Guangdong Province School of Chemistry and Chemical Engineering South China University of Technology Guangzhou 510640 People's Republic of China
- State Key Laboratory of Applied Organic Chemistry (Lanzhou University) Lanzhou 730000 People's Republic of China
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8
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Kaldhi D, Vodnala N, Gujjarappa R, Nayak S, Ravichandiran V, Gupta S, Hazra CK, Malakar CC. Organocatalytic oxidative synthesis of C2-functionalized benzoxazoles, naphthoxazoles, benzothiazoles and benzimidazoles. Tetrahedron Lett 2019. [DOI: 10.1016/j.tetlet.2018.12.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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9
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Nematollahi D, Namdar A, Momeni S. Cyclic voltammetry-assisted mechanistic evaluation of sulfonamide synthesis. A simple and green method for the synthesis of N-(1-hydroxynaphthalen-2-yl)benzenesulfonamide derivatives. J Electroanal Chem (Lausanne) 2018. [DOI: 10.1016/j.jelechem.2018.01.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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10
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Liu L, Qian LW, Wu S, Dong J, Xu Q, Zhou Y, Yin SF. Selective Aerobic C–H Amination of Phenols with Primary Amines over Copper toward Benzoxazoles. Org Lett 2017; 19:2849-2852. [DOI: 10.1021/acs.orglett.7b01061] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Long Liu
- State
Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry
and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Liang-Wei Qian
- State
Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry
and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Shaofeng Wu
- State
Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry
and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Jianyu Dong
- State
Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry
and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Qing Xu
- College
of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang 325035, China
| | - Yongbo Zhou
- State
Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry
and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Shuang-Feng Yin
- State
Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry
and Chemical Engineering, Hunan University, Changsha 410082, China
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11
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Gao S, Gao L, Meng H, Luo M, Zeng X. Iron-catalyzed synthesis of benzoxazoles by oxidative coupling/cyclization of phenol derivatives with benzoyl aldehyde oximes. Chem Commun (Camb) 2017; 53:9886-9889. [DOI: 10.1039/c7cc04965j] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
An iron-catalyzed oxidative coupling/cyclization reaction for the synthesis of benzoxazoles at room temperature is reported.
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Affiliation(s)
- Sen Gao
- Key Laboratory of Green Chemistry & Technology of Ministry of Education
- College of Chemistry
- Sichuan University
- Chengdu 610064
- P. R. China
| | - Liming Gao
- Institute for the Control of Agrochemicals of Sichuan Province Chengdu
- Sichuan
- P. R. China
| | - Hong Meng
- Key Laboratory of Green Chemistry & Technology of Ministry of Education
- College of Chemistry
- Sichuan University
- Chengdu 610064
- P. R. China
| | - Meiming Luo
- Key Laboratory of Green Chemistry & Technology of Ministry of Education
- College of Chemistry
- Sichuan University
- Chengdu 610064
- P. R. China
| | - Xiaoming Zeng
- Key Laboratory of Green Chemistry & Technology of Ministry of Education
- College of Chemistry
- Sichuan University
- Chengdu 610064
- P. R. China
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12
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Weischedel H, Sudheendran K, Mikhael A, Conrad J, Frey W, Beifuss U. Formation of substituted 1-naphthols and related products via dimerization of alkyl 3-( o -halo(het)aryl)-oxopropanoates based on a CuI-catalyzed domino C -arylation/condensation/aromatization process. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.04.067] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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13
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Prasad KV, Saidachary G, Hariprasad KS, Nagaraju P, Rao VJ, Raju BC. Copper-Catalyzed C−H Oxygenation of Benzoxepine-4-carboxylates: Facile Synthesis and Photophysical Properties of Naphtho[2,1-d]oxazoles and Benzo[c]phenoxazines. ASIAN J ORG CHEM 2016. [DOI: 10.1002/ajoc.201600131] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Kasagani Veera Prasad
- Natural Products Chemistry Division; CSIR-Indian Institute of Chemical Technology; Hyderabad 500007 India
| | - Gannerla Saidachary
- Natural Products Chemistry Division; CSIR-Indian Institute of Chemical Technology; Hyderabad 500007 India
| | - Kurma Siva Hariprasad
- Natural Products Chemistry Division; CSIR-Indian Institute of Chemical Technology; Hyderabad 500007 India
| | - Peethani Nagaraju
- Crop Protection Chemical Division; CSIR-Indian Institute of Chemical Technology; Hyderabad 500007 India
| | - Vaidya Jayathirtha Rao
- Crop Protection Chemical Division; CSIR-Indian Institute of Chemical Technology; Hyderabad 500007 India
| | - Bhimapaka China Raju
- Natural Products Chemistry Division; CSIR-Indian Institute of Chemical Technology; Hyderabad 500007 India
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14
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Belal M, Khan AT. Synthesis of fused oxazole-containing coumarin derivatives via oxidative cross coupling reaction using a combination of CuCl2 and TBHP. RSC Adv 2016. [DOI: 10.1039/c5ra27993c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Various fused oxazoles containing coumarin derivatives were synthesized via an oxidative cross coupling reaction by employing 20 mol% CuCl2 as the catalyst and TBHP as an oxidant.
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Affiliation(s)
- Md. Belal
- Department of Chemistry
- Indian Institute of Technology Guwahati
- Guwahati 781 039
- India
| | - Abu T. Khan
- Department of Chemistry
- Indian Institute of Technology Guwahati
- Guwahati 781 039
- India
- Vice-Chancellor
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15
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Zhu D, Liu P, Lu W, Wang H, Luo B, Hu Y, Huang P, Wen S. Relayed Regioselective Alkynylation/Olefination of Unsymmetrical Cyclic Diaryliodonium Species Catalyzed by Cu and Pd: Affording Fluorescent Cytotoxic Benzoxazoles. Chemistry 2015; 21:18915-20. [PMID: 26516085 DOI: 10.1002/chem.201503791] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Indexed: 11/10/2022]
Abstract
Although cyclic diaryliodonium species have the potential to act as valuable synthons for cascade transformations, they still remain largely unexplored. The regioselectivity associated with unsymmetrical cyclic diaryliodonium species has previously been known to pose a challenge. A regioselective relayed alkynylation and olefination of unsymmetrical cyclic diaryliodonium species has been achieved by installation of a directing amido group. These relayed transformations were delayed until an oxazole ring had formed, delivering a series of unique fluorescent benzoxazoles. Moreover, some of these synthetic benzoxazoles showed apparent inhibitory activity against malignant cancer cells. Further confocal visualization revealed that benzoxazoles targeted cell nuclei. These findings might provide a novel structural scaffold to develop desirable anticancer agents.
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Affiliation(s)
- Daqian Zhu
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University 651 Dongfeng East Road, Guangzhou 510060 (China).,School of Pharmaceutical Sciences, Sun Yat-sen University, 132 Waihuan East Road, Guangzhou 510006 (China)
| | - Panpan Liu
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University 651 Dongfeng East Road, Guangzhou 510060 (China)
| | - Wenhua Lu
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University 651 Dongfeng East Road, Guangzhou 510060 (China)
| | - Haiwen Wang
- School of Pharmaceutical Sciences, Sun Yat-sen University, 132 Waihuan East Road, Guangzhou 510006 (China)
| | - Bingling Luo
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University 651 Dongfeng East Road, Guangzhou 510060 (China).,School of Pharmaceutical Sciences, Sun Yat-sen University, 132 Waihuan East Road, Guangzhou 510006 (China)
| | - Yumin Hu
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University 651 Dongfeng East Road, Guangzhou 510060 (China)
| | - Peng Huang
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University 651 Dongfeng East Road, Guangzhou 510060 (China).
| | - Shijun Wen
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University 651 Dongfeng East Road, Guangzhou 510060 (China). .,School of Pharmaceutical Sciences, Sun Yat-sen University, 132 Waihuan East Road, Guangzhou 510006 (China).
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16
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Aljaar N, Malakar CC, Conrad J, Beifuss U. Base-Promoted Domino Reaction of 5-Substituted 2-Nitrosophenols with Bromomethyl Aryl Ketones: A Transition-Metal-Free Approach to 2-Aroylbenzoxazoles. J Org Chem 2015; 80:10829-37. [PMID: 26399156 DOI: 10.1021/acs.joc.5b02000] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction of 5-substituted 2-nitrosophenols with bromomethyl aryl ketones and related compounds employing K2CO3 as a base in refluxing THF and DMF at 80 °C, respectively, delivers 2-aroylbenzoxazoles in a single step with yields up to 85%. The new method involves an intermolecular nucleophilic substitution followed by intramolecular 1,2-addition and elimination. It allows an efficient and practical access to 2-aroylbenzoxazoles under transition-metal-free conditions.
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Affiliation(s)
- Nayyef Aljaar
- Bioorganische Chemie, Institut für Chemie, Universität Hohenheim , Garbenstraße 30, D-70599 Stuttgart, Germany.,Faculty of Pharmacy and Medical Sciences, Al-Ahliyya Amman University , Amman 19328, Jordan
| | - Chandi C Malakar
- Bioorganische Chemie, Institut für Chemie, Universität Hohenheim , Garbenstraße 30, D-70599 Stuttgart, Germany
| | - Jürgen Conrad
- Bioorganische Chemie, Institut für Chemie, Universität Hohenheim , Garbenstraße 30, D-70599 Stuttgart, Germany
| | - Uwe Beifuss
- Bioorganische Chemie, Institut für Chemie, Universität Hohenheim , Garbenstraße 30, D-70599 Stuttgart, Germany
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17
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Song XR, Qiu YF, Song B, Hao XH, Han YP, Gao P, Liu XY, Liang YM. BF3·Et2O-Promoted Cleavage of the Csp–Csp2 Bond of 2-Propynolphenols/Anilines: Route to C2-Alkenylated Benzoxazoles and Benzimidazoles. J Org Chem 2015; 80:2263-71. [DOI: 10.1021/jo502761x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Xian-Rong Song
- State Key Laboratory
of Applied Organic
Chemistry, Lanzhou University, Lanzhou 730000, P.R. China
| | - Yi-Feng Qiu
- State Key Laboratory
of Applied Organic
Chemistry, Lanzhou University, Lanzhou 730000, P.R. China
| | - Bo Song
- State Key Laboratory
of Applied Organic
Chemistry, Lanzhou University, Lanzhou 730000, P.R. China
| | - Xin-Hua Hao
- State Key Laboratory
of Applied Organic
Chemistry, Lanzhou University, Lanzhou 730000, P.R. China
| | - Ya-Ping Han
- State Key Laboratory
of Applied Organic
Chemistry, Lanzhou University, Lanzhou 730000, P.R. China
| | - Pin Gao
- State Key Laboratory
of Applied Organic
Chemistry, Lanzhou University, Lanzhou 730000, P.R. China
| | - Xue-Yuan Liu
- State Key Laboratory
of Applied Organic
Chemistry, Lanzhou University, Lanzhou 730000, P.R. China
| | - Yong-Min Liang
- State Key Laboratory
of Applied Organic
Chemistry, Lanzhou University, Lanzhou 730000, P.R. China
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