Login Register Cart 0
Generic placeholder image

Current Organic Synthesis

Editor-in-Chief

ISSN (Print): 1570-1794
ISSN (Online): 1875-6271

Back
Journal Home About Journal Editorial Board Journal Insight Current Issue Volumes/Issues
Subscribe
Research Article

Copper(II)-catalyzed Synthesis of Benzoxazoles from Inactive 2-chloroanilides

Author(s): Yuan Jiang, Yanling Tang, Hui Gao*, Gaoxiong Rao and Zewei Mao*

Volume 19, Issue 7, 2022

Published on: 20 May, 2022

Page: [819 - 823] Pages: 5

DOI: 10.2174/1570179419666220225115017

Price: $65

conference banner
Abstract

Aim and Objective: Benzoxazoles are of great importance in natural products, pharmaceutical agents as well as synthetic intermediates. Although many works on the construction of benzoxazoles by Cu-catalyzed intramolecular O-arylation of ortho-haloanilides have been reported, only a few reports about transition metal-catalyzed synthesis of benzoxazoles from inactive 2-chloroanilides so far. This work aimed to explore a green and cheap protocol for intramolecular O-arylation of inactive 2-chloroanilides to prepare 2-arylbenzoxazoles.

Materials and Methods: We found that Cu(acac)2/1,10-Phen complex was beneficial to intramolecular O-arylation of 2-chloroanilides using K2CO3 as a base in EtOH at 90 °C to prepare benzoxazoles.

Results: An efficient and green method was developed for Cu(II)-catalyzed intramolecular Oarylation of inactive 2-chloroanilides.

Conclusion: In this way, many 2-arylbenzoxazoles were prepared in good yields.

Keywords: Cu-catalyzed, O-arylation, benzoxazoles, 2-chloroanilides, heterocyclic compounds, pharmaceutical agents.

« Previous Next »
Graphical Abstract

[1]
(a) Eftekhari-Sis, B.; Zirak, M.; Akbari, A. Arylglyoxals in synthesis of heterocyclic compounds. Chem. Rev., 2013, 113(5), 2958-3043.
[http://dx.doi.org/10.1021/cr300176g] [PMID: 23347156]
(b) Stępień, M.; Gońka, E.; Żyła, M.; Sprutta, N. Heterocyclic nanographenes and other polycyclic heteroaromatic compounds: Synthetic routes, properties, and applications. Chem. Rev., 2017, 117(4), 3479-3716.
[http://dx.doi.org/10.1021/acs.chemrev.6b00076] [PMID: 27258218]
(c) Johnson, S.M.; Connelly, S.; Wilson, I.A.; Kelly, J.W. Biochemical and structural evaluation of highly selective 2-arylbenzoxazole-based transthyretin amyloidogenesis inhibitors. J. Med. Chem., 2008, 51(2), 260-270.
[http://dx.doi.org/10.1021/jm0708735] [PMID: 18095641]
[2]
(a) Lohr, T.L.; Li, Z.; Marks, T.J. Thermodynamic strategies for C-O bond formation and cleavage via tandem catalysis. Acc. Chem. Res., 2016, 49(5), 824-834.
[http://dx.doi.org/10.1021/acs.accounts.6b00069] [PMID: 27078085]
(b) Kuwabe, S.I.; Torraca, K.E.; Buchwald, S.L. Palladium-catalyzed intramolecular C-O bond formation. J. Am. Chem. Soc., 2001, 123(49), 12202-12206.
[http://dx.doi.org/10.1021/ja012046d] [PMID: 11734019]
(c) Peng, Y.; Cui, L.; Zhang, G.; Zhang, L. Gold-catalyzed homogeneous oxidative C-O bond formation: efficient synthesis of 1-benzoxyvinyl ketones. J. Am. Chem. Soc., 2009, 131(14), 5062-5063.
[http://dx.doi.org/10.1021/ja901048w] [PMID: 19301899]
(d) Pandey, G.; Laha, R.; Singh, D.; Benzylic, C. Benzylic C(sp(3))-H functionalization for C-N and C-O bond formation via visible light photoredox catalysis. J. Org. Chem., 2016, 81(16), 7161-7171.
[http://dx.doi.org/10.1021/acs.joc.6b00970] [PMID: 27269307]
[3]
(a) Chang, J.; Zhao, K.; Pan, S. Synthesis of 2-arylbenzoxazoles via DDQ promoted oxidative cyclization of phenolic Schiff bases—a solu-tion-phase strategy for library synthesis. Tetrahedron Lett., 2002, 43(6), 951-954.
[http://dx.doi.org/10.1016/S0040-4039(01)02302-4]
(b) Inamdar, S.M.; More, V.K.; Mandal, S.K. CuO nano-particles supported on silica, a new catalyst for facile synthesis of benzimidazoles, benzothiazoles and benzoxazoles. Tetrahedron Lett., 2013, 54(6), 579-583.
[http://dx.doi.org/10.1016/j.tetlet.2012.11.091]
(c) Gao, W.Ch.; Hu, F.; Huo, Y.M.; Chang, H.H.; Li, X.; Wei, W.L. I2-catalyzed C-O bond formation and dehydrogenation: Facile synthesis of oxazolines and oxazoles controlled by bases. Org. Lett., 2015, 17(15), 3914-3917.
[http://dx.doi.org/10.1021/acs.orglett.5b01933] [PMID: 26226059]
[4]
(a) Chan, D.G.; Winternheimer, D.J.; Merlic, C.A. Enol silyl ethers via copper(II)-catalyzed C-O bond formation. Org. Lett., 2011, 13(10), 2778-2781.
[http://dx.doi.org/10.1021/ol2009297] [PMID: 21510621]
(b) Modak, A.; Dutta, U.; Kancherla, R.; Maity, S.; Bhadra, M.; Mobin, S.M.; Maiti, D. Predictably selective (sp3)C-O bond formation through copper catalyzed dehydrogenative coupling: facile synthesis of dihydro-oxazinone derivatives. Org. Lett., 2014, 16(10), 2602-2605.
[http://dx.doi.org/10.1021/ol500670h] [PMID: 24761793]
(c) Guru, M.M.; Ali, M.A.; Punniyamurthy, T. Copper-mediated synthesis of substituted 2-aryl-N-benzylbenzimidazoles and 2-arylbenzoxazoles via C-H functionalization/C-N/C-O bond formation. J. Org. Chem., 2011, 76(13), 5295-5308.
[http://dx.doi.org/10.1021/jo2005632] [PMID: 21598946]
(d) Ueda, S.; Nagasawa, H. Copper-catalyzed synthesis of benzoxazoles via a regioselective C-H functionalization/C-O bond formation un-der an air atmosphere. J. Org. Chem., 2009, 74(11), 4272-4277.
[http://dx.doi.org/10.1021/jo900513z] [PMID: 19382756]
[5]
(a) Zhang, M.; Ruzi, R.; Li, N.; Xie, J.; Zhu, C. Photoredox and cobalt co-catalyzed C(sp2)–H functionalization/C–O bond formation for synthesis of lactones under oxidant- and acceptor-free conditions. Org. Chem. Front., 2018, 5(5), 749-752.
[http://dx.doi.org/10.1039/C7QO00795G]
(b) Li, Z.L.; Wu, P.Y.; Cai, C. Cobalt catalyzed regioselective C–H methylation/acetoxylation of anilides: new routes for C–C and C–O bond formation. Org. Chem. Front., 2019, 6(12), 2043-2047.
[http://dx.doi.org/10.1039/C9QO00411D]
[6]
(a) Bakhoda, A.G.; Wiese, S.; Greene, C.; Figula, B.C.; Bertke, J.A.; Warren, T.H. Radical capture at nickel(II) complexes: C–C, C–N, and C–O bond formation. Organometallics, 2020, 39(10), 1710-1718. Org. Chem., 2018, 83(2), 973-979.
[http://dx.doi.org/10.1021/acs.organomet.0c00021] [http://dx.doi.org/10.1021/acs.joc.7b02281] [PMID: 29281885]
[7]
(a) Sasmal, S.; Sen, I.; Hall, R.G.; Pal, S. Intermolecular coupling of 2-iodoanilides with benzoxazoles: synthesis of N-(2-Benzoxazol-2-ylphenyl)benzamides via C–H activation. Tetrahedron Lett., 2015, 56(11), 1374-1377.
[http://dx.doi.org/10.1016/j.tetlet.2015.01.150]
(b) Bansal, S. Recent advances in synthesis of benzoxazole. Mini Rev. Org. Chem., 2021, 18(3), 383-397.
[http://dx.doi.org/10.2174/1570193X17999200706010457]
[8]
(a) Evindar, G.; Batey, R.A. Parallel synthesis of a library of benzoxazoles and benzothiazoles using ligand-accelerated copper-catalyzed cyclizations of ortho-halobenzanilides. J. Org. Chem., 2006, 71(5), 1802-1808.
[http://dx.doi.org/10.1021/jo051927q] [PMID: 16496964]
(b) Wu, F.; Zhang, J.; Wei, Q.; Liu, P.; Xie, J.; Jiang, H.; Dai, B. Copper-catalysed intramolecular O-arylation: a simple and efficient method for benzoxazole synthesis. Org. Biomol. Chem., 2014, 12(47), 9696-9701.
[http://dx.doi.org/10.1039/C4OB02068E] [PMID: 25350639]
(c) Mishra, N.; Singh, A.S.; Agrahari, A.K.; Singh, S.K.; Singh, M.; Tiwari, V.K. Synthesis of benz-fused azoles via C-heteroatom coupling reactions catalyzed by Cu(I) in the presence of glycosyltriazole ligands. ACS Comb. Sci., 2019, 21(5), 389-399.
[http://dx.doi.org/10.1021/acscombsci.9b00004] [PMID: 30943366]
[9]
(a) Li, M.; Li, M.; Tang, Y.; Sun, Y.; Qu, L.; Mao, Z. Cu(II)/Vasicine promoted intramolecular C-O formation: Synthesis of benzoxazoles in EtOH. Curr. Org. Synth., 2021, 18(3), 310-315.
[http://dx.doi.org/10.2174/1570179417666201109151752] [PMID: 33167843]
(b) Tang, Y.; Li, M.; Gao, H.; Rao, G.; Mao, Z. Efficient Cu-catalyzed intramolecular O-arylation for synthesis of benzoxazoles in water. RSC Advances, 2020, 10(24), 14317-14321.
[http://dx.doi.org/10.1039/D0RA00570C]

Rights & Permissions Print Cite
Article Metrics
33
1
Wayfinder Image
© 2024 Bentham Science Publishers | Privacy Policy