Synlett, Table of Contents Synlett 2020; 31(04): 359-362DOI: 10.1055/s-0037-1610743 letter © Georg Thieme Verlag Stuttgart · New YorkCopper-Catalyzed Synthesis of Alkyl-Substituted Pyrrolo[1,2-a]quinoxalines from 2-(1H-Pyrrol-1-yl)anilines and Alkylboronic Acids Authors Author Affiliations Xin Guan Rulong Yan∗ State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Department of Chemistry, Lanzhou University, Lanzhou, 730000, Gansu, P. R. of China Email: yanrl@lzu.edu.cn Recommend Article Abstract Buy Article(opens in new window) All articles of this category(opens in new window) Abstract A radical pathway for the construction of pyrrolo[1,2-a]quinoxalines by using 2-(1H-pyrrol-1-yl)anilines and alkylboronic acids has been developed. Features of this process include Cu catalysis, readily accessible starting materials, and simple operations. Alkylboronic acids are used for the construction of pyrrolo[1,2-a]quinoxaline derivatives, and the desired products are obtained in moderate yields. Key words Key wordspyrrolylanilines - alkylboronic acids - pyrroloquinoxalines - radical reaction Full Text References References and Notes 1a Torres E, Moreno E, Ancizu S, Barea C, Galiano S, Aldana I, Monge A, Pérez-Silanes S. Bioorg. Med. Chem. Lett. 2011; 21: 3699 1b Le T, Yu H, Niu X. Food Chem. 2015; 175: 85 1c Su W, Xiao M, Fan Q, Zhong J, Chen J, Dang D, Shi J, Xiong W, Duan X, Tan H, Liu Y, Zhu W. Org. Electron. 2015; 17: 129 1d Wang L, Yang X, Wang X, Sun L. Dyes Pigm. 2015; 113: 581 1e Carta A, Loriga M, Paglietti G, Mattana AP, Fiori L, Mollicotti P, Sechi L, Zanetti S. Eur. J. Med. Chem. 2004; 39: 195 2 Moarbess G, Deleuze-Masquefa C, Bonnard V, Gayraud-Paniagua S, Vidal J.-R, Bressolle F, Pinguetand F, Bonnet P.-A. Bioorg. Med. 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Chem. 2018; 83: 4239 16 4-Propylpyrrolo[1,2-a]quinoxaline (3aa):2 Typical Procedure A mixture of 2-(1H-pyrrol-1-yl)aniline (1a; 1 equiv, 0.3 mmol), BuB(OH)2 (2a; 3 equiv, 0.9 mmol), PivOH (1 equiv, 0.3 mmol), Cu(OPiv)2 (10 mol%, 0.03 mmol), and DCM (1 mL) was stirred at 80 °C under O2 (balloon) for 8 h. Upon completion of the reaction (TLC), the mixture was concentrated in vacuo, and the crude product was purified by column chromatography [silica, gel, PE–EtOAc (10:1)] to give a light-yellow solid; yield: (40.3 mg, 73%); mp 45–46 °C. 1H NMR (400 MHz, CDCl3): δ = 7.94–7.90 (m, 1 H), 7.90–7.89 (m, 1 H), 7.84–7.80 (m, 1 H), 7.49–7.44 (m, 1 H), 7.44–7.39 (m, 1 H), 6.92–6.89 (m, 1 H), 6.85–6.83 (m, 1 H), 3.02–2.97 (m, 2 H), 1.99–1.89 (m, 2 H), 1.10–1.05 (m, 3 H). 13C NMR (100 MHz, CDCl3): δ = 157.4, 136.0, 129.4, 127.3, 126.8, 126.1, 125.0, 114.1, 113.6, 113.4, 106.3, 37.8, 22.0, 14.3. HRMS (ESI): m/z [M + H]+ calcd for C14H15N2: 211.1230; found: 211.1227. 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