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. 2022 Jul 21;12(33):21022-21025.
doi: 10.1039/d2ra04191j.

Metal-free synthesis of C2-quaternary indolinones by (NH4)2S2O8 mediated oxidative dearomatization of indoles

Yu Dong  1 , Jun-Hu Qian  1 , Xiang-Long Chen  1 , Hui Jiang  1 , Xue Li  1 , Qiang Zhou  1 , Ting Mei  1 , Zhi-Chuan Shi  2 , Zhong-Hui Li  1 , Bing He  1
Affiliations

Metal-free synthesis of C2-quaternary indolinones by (NH4)2S2O8 mediated oxidative dearomatization of indoles

Yu Dong et al. RSC Adv. .

Abstract

An efficient metal-free, (NH4)2S2O8 mediated oxidative dearomatization of indoles for the construction of C2-quaternary indolinones was disclosed. A series of C2-quaternary indolinones derivatives with good functional group tolerance were obtained in moderate to excellent yields. This methodology provides an alternative approach for the direct generation of all-carbon quaternary centers at the C2 position of indoles. This catalytic approach represents a step-economic and convenient strategy for the oxidative dearomatization of indoles.

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Conflict of interest statement

There are no conflicts to declare.

Figures

Fig. 1
Fig. 1. Some important bioactive synthetic derivatives with 2,2-disubstituted indolin-3-one structural unit.
Scheme 1
Scheme 1. Previous and present approaches for the synthesis of 2,2-diaryloxindole (R = alkyl or halide group).
Scheme 2
Scheme 2. Plausible reaction mechanism.
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References

    1. Vitaku E. Smith D. T. Njardarson J. T. Analysis of the structural diversity, substitution patterns, and frequency of nitrogen heterocycles among US FDA approved pharmaceuticals: miniperspective. J. Med. Chem. 2014;57:10257–10274. - PubMed
    2. Taylor R. D. MacCoss M. Lawson A. D. Rings in drugs: Miniperspective. J. Med. Chem. 2014;57:5845–5859. - PubMed
    1. Sundberg R., Indoles, Academic Press, San Diego, 1996, p. 113
    2. Cacchi S. Fabrizi G. Synthesis and functionalization of indoles through palladium-catalyzed reactions. Chem. Rev. 2005;105:2873–2920. - PubMed
    3. Joucla L. Djakovitch L. Transition Metal-Catalysed, Direct and Site-Selective N1-, C2-or C3-Arylation of the Indole Nucleus: 20 Years of Improvements. Adv. Synth. Catal. 2009;351:673–714.
    4. Bandini M. Eichholzer A. Catalytic functionalization of indoles in a new dimension. Angew. Chem., Int. Ed. 2009;48:9608–9644. - PubMed
    5. Bartoli G. Bencivenni G. Dalpozzo R. Organocatalytic strategies for the asymmetric functionalization of indoles. Chem. Soc. Rev. 2010;39:4449–4465. - PubMed
    1. Gazit A. Osherov N. Posner I. Yaish P. Poradosu E. Gilon C. Levitzki A. Tyrphostins. II. Heterocyclic and. alpha.-substituted benzylidenemalononitrile tyrphostins as potent inhibitors of EGF receptor and ErbB2/neu tyrosine kinases. J. Med. Chem. 1991;34:1896–1907. - PubMed
    2. Dilber S. Saban M. Jelaca J. Gelineo A. Arsenijević L. Bogavac M. Investigation of antimicrobial activity of some isatin derivatives. Pharmazie. 1989;44:649–650. - PubMed
    3. Wetzel A. Gagosz F. Gold-Catalyzed Transformation of 2-Alkynyl Arylazides: Efficient Access to the Valuable Pseudoindoxyl and Indolyl Frameworks. Angew. Chem., Int. Ed. 2011;123:7492–7496. - PubMed
    4. Kumar C. V. S. Puranik V. G. Ramana C. V. InCl3-Mediated Addition of Indole to Isatogens: An Expeditious Synthesis of 13-deoxy-Isatisine A. Chem.–Eur. J. 2012;18:9601–9611. - PubMed
    1. Linhares M. Rebelo S. L. Simoes M. M. Silva A. M. Neves M. G. P. Cavaleiro J. A. Freire C. Biomimetic oxidation of indole by Mn (III) porphyrins. Appl. Catal. 2014;470:427–433.
    1. Bell R. Carmeli S. Sar N. Vibrindole A, a metabolite of the marine bacterium, Vibrio parahaemolyticus, isolated from the toxic mucus of the boxfish Ostracion cubicus. J. Nat. Prod. 1994;57:1587–1590. - PubMed