Expedient Route to Access C8-Carbonylated Quinolines via Photo-Induced C(sp³)–H Oxidation

Abstract

Visible light-enabled C(sp³)–H oxidation of 8-alkylquinolines has been accomplished utilizing [Mes-Acr-Me]BF₄ under air. The reaction offers an effective synthetic approach to direct access of C8-carbonyl quinolines bearing aldehydes, ketones, and esters groups and allows other important functional handles through postsynthetic modification. The site-selective C(sp³)–H oxidation, use of air as oxidant, substrate scope, and postsynthetic potential are the salient practical features.

Keywords

Quinoline modification - Photo-catalysis - C(sp³)–H oxidation - Organo-photocatalyst - Metal-free approach

Publication History

Received: 04 August 2025

Accepted after revision: 24 September 2025

Accepted Manuscript online:
24 September 2025

Article published online:
27 October 2025

• References


For photocatalytic C–H oxidation, see:
• 1a Zhang L, Yi H, Wang J, Lei A. Green Chem 2016; 18: 5122
• 1b Chen H, Liu F. Molecules 2024; 29: 5277
• 1c Zhang L, Li R-H, Li X-X. et al. Nat Commun 2024; 15: 537
• 1d Fan Y, Jiang Y, Lin H. et al. Nat Commun 2024; 15: 4679
• 1e Yang C, Wang H, Xie P. ChemSusChem 2025; 18: e202401915
• 1f Chao M, Zhang Q, Jin G, Guo G, Cheng X, Shen D. Tetrahedron 2025; 174: 134496

For example, see:
• 2a O’Hara F, Blackmond DG, Baran PS. J Am Chem Soc 2013; 135: 12122
• 2b Roth HG, Romero NA, Nicewicz DA. Synlett 2015; 27: 714
• 2c Lepori M, Schmid S, Barham JP. Beilstein J Org Chem 2023; 19: 1055
• 2d Zhu Z, Wu X, Li Z, Nicewicz DA. Acc Chem Res 2025; 58: 1094

For importance of quinoline, see:
• 3a Kimyonok A, Wang XY, Weck M. Polym Rev 2006; 46: 47
• 3b Okamoto T, Kobayashi T, Yoshida S. Med Chem 2007; 3: 35
• 3c Michael JP. Nat Prod Rep 2008; 25: 166
• 3d Nien CY, Chen YC, Kuo CC. et al. J Med Chem 2010; 53: 2309
• 3e Solomon VR, Lee H. Curr Med Chem 2011; 18: 1488
• 3f Shao A, Xie Y, Zhu S. et al. Angew Chem Int Ed 2015; 54: 7275
• 3g Varejão JOS, Varejão EVV, Fernandes SA. Eur J Org Chem 2019; 2019: 4273
• 3h Gao P, Wang L, Zhao L. et al. Phytochem 2020; 172: 112260

For quinoline functionalization, see:
• 4a McGlacken GP, Bateman LM. Chem Soc Rev 2009; 38: 2447
• 4b Talwar D, Gonzalez-de-Castro A, Li HY, Xiao J. Angew Chem Int Ed 2015; 54: 5223
• 4c Iwai T, Sawamura M. ACS Catal 2015; 5: 5031
• 4d Romero EA, Chen G, Gembicky M, Jazzar R, Yu J-Q, Bertrand G. J Am Chem Soc 2019; 141: 16726
• 4e Zhao B, Prabagar B, Shi Z. Chem 2021; 7: 2585
• 4f Bellotti P, Rogge T, Paulus F. et al. J Am Chem Soc 2022; 144: 15662
• 4g Guo R, Adak S, Bellotti P. et al. J Am Chem Soc 2022; 144: 17680
• 4h Mandal S, Karjee P, Saha S, Punniyamurthy T. Chem Commun 2023; 59: 2823
• 4i Basak S, Paul T, Mandal S, Karjee P, Nanjegowda MV, Punniyamurthy T. Synthesis. 2023 55. A-P

For examples, see:
• 5a Cho SH, Hwang SJ, Chang S. J Am Chem Soc 2008; 130: 9254
• 5b Larionov OV, Stephens D, Mfuh A, Chavez G. Org Lett 2014; 16: 864
• 5c Wang D, Désaubry L, Li G, Huang M, Zheng S. Adv Synth Catal 2021; 363: 2
• 5d Corio A, Gravier-Pelletier C, Busca P. Molecules 2021; 26: 5467

For quinoline C(sp³)–H functionalizations, see:
• 6a Chen X, Goodhue CE, Yu J-Q. J Am Chem Soc 2006; 128: 12634
• 6b Liu B, Zhou T, Li B, Xu S, Song H, Wang B. Angew Chem Int Ed 2014; 53: 4191
• 6c Yu S, Li Y, Kong L. et al. ACS Catal 2016; 6: 7744
• 6d Kim JH, Greßies S, Arapinis MB, Daniliuc C, Glorius F. ACS Catal 2016; 6: 7652
• 6e Yan SY, Ling PX, Shi BF. Adv Synth Catal 2017; 359: 2912
• 6f Liu B, Hu P, Zhou X, Bai D, Chang J, Li X. Org Lett 2017; 19: 2086
• 6g Shan B, Kang B, Song M. et al. Adv Synth Catal 2020; 362: 2541
• 6h Mandal S, Barman M, Debnath B, Punniyamurthy T. Org Lett 2024; 26: 7560
• 6i Parmar D, Kumar R, Sharma U. Chem Asian J 2025; 20: e202401266

For example, see:
• 7a Sauermann N, Meyer TH, Tian C, Ackermann L. J Am Chem Soc 2017; 139: 18452
• 7b Twilton J, Le C, Zhang P, Shaw MH, Evans RW, MacMillan DWC. Nat Rev Chem 2017; 1: 0052
• 7c Silvi M, Melchiorre P. Nature 2018; 554: 41
• 7d Lesieur M, Genicot C, Pasau P. Org Lett 2018; 20: 1987
• 7e Dalton T, Faber T, Glorius F. ACS Cent Sci 2021; 7: 245
• 7f Oliva M, Coppola GA, Van der Eycken EV, Sharma UK. Adv Synth Catal 2021; 363: 1810
• 7g Ganesh KN, Zhang D, Miller SJ. et al. Environ Sci Technol 2021; 55: 8459
• 7h Murugesan K, Donabauer K, König B. Angew Chem Int Ed 2021; 60: 2439
• 7i Zhao R, Surke M, Lin Z, Alsalme A, Ackermann L. Curr Res Green Sustainable Chem 2023; 7: 100377
• 7j Sharma S, Gallou F, Handa S. Green Chem 2024; 26: 6289

For aldehyde transformation and coupling reaction, see:
• 8a Li X, Yang X, Qi Z. ACS Catal 2016; 6: 6372
• 8b Ghosh B, Samanta R. Chem Commun 2019; 55: 6886
• 8c Kushwaha AK, Maury SK, Kamal A, Singh HK, Pandey S, Singh S. Chem Commun 2023; 59: 4075
• 8d Thakur DG, Sonawane MA, Patel RN. et al. Adv Synth Catal 2024; 366: 4994
• 8e Xu Q, Ou W, Hou H, Wang Q, Yu L, Su C. Org Lett 2024; 26: 4098

For example, see:
• 9a Pokhrel L, Kim Y, Nguyen TDT. et al. Bioorg Med Chem Lett 2012; 22: 3480
• 9b Xu Y, Yan G, Ren Z, Dong G. Nat Chem 2015; 7: 829
• 9c Uygur M, Kuhlmann JH, Pérez-Aguilar MC, Piekarski DG, García Mancheño O. Green Chem 2021; 23: 3392

For example, see:
• 10a Guillemard L, Wencel-Delord J. Beilstein J Org Chem 2020; 16: 1754
• 10b Tlili A, Lakhdar S. Angew Chem Int Ed 2021; 60: 19526
• 10c Singh PP, Singh J, Srivastava V. RSC Adv 2023; 13: 10958