Electrochemical Synthesis of Pyrrolo[1,2-a]quinoxalines by Cyclization of 2-(1H-pyrrol-1-yl)anilines and Alcohols

Abstract

The electrochemical synthesis of pyrrolo[1,2-a]quinoxalines features the use of ethanol as both the reactant and solvent and a broad substrate scope, thus affording a wide range of 4methylpyrrolo[1,2-a]quinoxalines in moderate to good yields. Notably, for this efficient electrochemical synthesis protocol, neither metal catalysts nor exogenous additives/oxidants are required. Additionally, gram-scale reaction demonstrated the synthetic usefulness of this protocol.

Keywords

Electrooxidation - 2-(1H-pyrrol-1-yl)anilines - Ethanol - Cyclization - Pyrrolo[1,2-a]quinoxalines

Publication History

Received: 13 November 2025

Accepted after revision: 16 December 2025

Accepted Manuscript online:
16 December 2025

Article published online:
13 January 2026

• References

• 1a Koleda O, Prane K, Suna E. Org Lett 2023; 25: 7958
• 1b Xiang F, Wang D, Xu K, Zeng C-C. Org Lett 2023; 26: 411
• 1c Zheng J-M, Li Y-F, Pan Y-X, Hu X-D, Ye X-X, Li R-H. Green Chem 2023; 25: 3016
• 1d Zhong Q, Wang P-L, Gao H, Ma F, Yang Y, Li H. Green Chem 2023; 25: 3982
• 1e Darzina M, Jirgensons A. Org Lett 2024; 26: 2158
• 1f Qiang C, Zhang T, Feng Z, Liu P, Sun P. Org Lett 2024; 26: 493
• 1g Tan Z, Zhang H, Xu K, Zeng C. Sci China Chem 2024; 67: 450
• 2a Yan M, Kawamata Y, Baran PS. Chem Rev 2017; 117: 13230
• 2b Kärkäs MD. Chem Soc Rev 2018; 47: 5786
• 2c Kawamata Y, Vantourout JC, Hickey DP. et al. J Am Chem Soc 2019; 141: 6392
• 2d Zhu C, Ang NW, Meyer TH, Qiu Y, Ackermann L. ACS Cent Sci 2021; 7: 415
• 2e Sun F, Miao M, Li W. et al. Org Biomol Chem 2024; 22: 472
• 2f Huang J, Liu Y, Huang Y. et al. Org Biomol Chem 2025; 23: 4860
• 2g Li J, Wang R, Huang Q, Li W, An Z, Liu Y. Tetrahedron 2025; 184: 134746
• 2h Li W, Li J, Sun F. et al. Eur J Org Chem 2025; 28: e202401226
• 2i Pan Y, Qi Z, Li W. et al. Org Biomol Chem 2025; 23: 5081
• 2j Sun F, Miao M, Huang Y. et al. J Org Chem 2025; 90: 2307
• 3a Li J, Zhang J, Chen J. et al. J Comb Chem 2006; 8: 326
• 3b Lai SC, Koper MT. Faraday Discuss 2009; 140: 399
• 3c Lai SC, Kleijn SE, Öztürk FT. et al. Catal Today 2010; 154: 92
• 3d Sulaiman JE, Zhu S, Xing Z, Chang Q, Shao M. ACS Catal 2017; 7: 5134
• 3e Liu X, Wang K, Zhou L. et al. ACS Sustain Chem Eng 2020; 8: 6449
• 3f Qiu Y, Zhang J, Jin J. et al. Nat Commun 2021; 12: 5273
• 4a Han L, Ju H, Xu Y. Int J Hydrog Energy 2012; 37: 15156
• 4b Li M, Song K, He J. et al. Nat Mach Intell 2025; 7 (08) 1355-1368
• 5a Sun J, Wang Y. ACS Catal 2014; 4: 1078
• 5b Wang Y, Zou S, Cai W-B. Catalysts 2015; 5: 1507
• 5c Pomalaza G, Ponton PA, Capron M, Dumeignil F. Cat Sci Technol 2020; 10: 4860
• 5d Zhang Z, Yang W, Liu C, Yu X, Song S, Xia C. Adv Synth Catal 2024; 366: 4667
• 5e Wu M, Wang Y, Lv X. et al. Org Biomol Chem 2025; 23: 2365
• 6 Li J, Zhang J, Yang H, Gao Z, Jiang G. J Org Chem 2017; 82: 765
• 7a Moarbess G, Deleuze-Masquefa C, Bonnard V. et al. Bioorg Med Chem 2008; 16: 6601
• 7b Gemma S, Colombo L, Forloni G. et al. Org Biomol Chem 2011; 9: 5137
• 7c Carullo G, Mazzotta S, Giordano F, Aiello FJ. Chem 2021; 2021: 5596816
• 7d Lu S, Chen Y, Wei J. et al. Acta Pharm Sin B 2021; 11: 1355
• 8 Guillon J, Forfar I, Mamani-Matsuda M. et al. Bioorg Med Chem 2007; 15: 194
• 9 Guillon J, Dallemagne P, Pfeiffer B. et al. Eur J Med Chem 1998; 33: 293
• 10 Guillon J, Reynolds C, Leger M. et al. J Enzym Inhib Med Chem 2004; 19: 489-495
• 11 Lin P, Salunke D, Chen L, Sun C. Org Biomol Chem 2011; 9: 2925
• 12 Campiani G, Morelli E, Gemma S. et al. J Med Chem 1999; 42: 4362
• 13a Kalinin AA, Mamedov VA. Chem Heterocycl Com 2011; 46: 1423
• 13b Fan Y-S, Jiang Y-J, An D, Sha D, Antilla JC, Zhang S. Org Lett 2014; 16: 6112
• 13c Xie C, Feng L, Li W. et al. Org Biomol Chem 2016; 14: 8529
• 13d Xie C, Zhang Z, Li D. et al. J Org Chem 2017; 82: 3491
• 13e Ni J, Jiang Y, Qi Z, Yan R. Chem–Asian J 2019; 14: 2898
• 13f Ni D, Chai Z, Wang Y. et al. WIRES Comput Mol Sci 2022; 12: e1585
• 14 Zhang Z, Liao LL, Yan SS. et al. Angew Chem Int Ed 2016; 55: 7068
• 15 Wang M, Liu C, Gu Y. Tetrahedron 2016; 72: 6854
• 16 An Z, Zhao L, Wu M. et al. Chem Commun 2017; 53: 11572
• 17 Sun F, Miao M, Li W. et al. Adv Synth Catal 2024; 366: 4649
• 18a Liu G, Zhou Y, Lin D. et al. ACS Comb Sci 2011; 13: 209
• 18b Zhang Z, Xie C, Tan X. et al. Org Chem Front 2015; 2: 942
• 18c Wang Y, Cui L, Wang Y, Zhou Z. Tetrahedron Asymmetry 2016; 27: 85
• 18d Li Q-Y, Cheng S-Y, Tang H-T, Pan Y-M. Green Chem 2019; 21: 5517