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Synlett 2020; 31(07): 695-698
DOI: 10.1055/s-0039-1691587
letter
© Georg Thieme Verlag Stuttgart · New York

Diiodine-Mediated Oxidative Reaction for the Construction of Imidazo[1,5-a]pyridines under Metal-Free Conditions

Kexin Su
a   State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Gansu Lanzhou, 730000, P. R. of China   Email: chenbh@lzu.edu.cn
,
Mingda Qin
a   State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Gansu Lanzhou, 730000, P. R. of China   Email: chenbh@lzu.edu.cn
,
Yongxin Chen
b   Key Laboratory of Petroleum Resources, Gansu Lanzhou, 730000, P. R. of China   Email: chenyongxin@lzb.ac.cn
,
Yafeng Liu
a   State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Gansu Lanzhou, 730000, P. R. of China   Email: chenbh@lzu.edu.cn
,
Yuan Tian
a   State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Gansu Lanzhou, 730000, P. R. of China   Email: chenbh@lzu.edu.cn
,
Baohua Chen  ∗
a   State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Gansu Lanzhou, 730000, P. R. of China   Email: chenbh@lzu.edu.cn
› Author AffiliationsFinancial support for this study from the Key Laboratory Project of Gansu Province (Grant No. 1309RTSA041).
Further Information

Publication History

Received: 21.11.20219

Accepted after revision: 05 January 2020

Publication Date:
04 February 2020 (online)

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Abstract

An efficient and general protocol has been developed for preparing imidazo[1,5-a]pyridines in moderate to excellent yields by an I2-mediated sequential dual oxidative C(sp3)–H amination of ethyl pyridin-2-ylacetates with benzylamines. The metal- and peroxide-free reaction involves oxidative dehydrogenation and two C–N couplings.

Key words

imidazopyridines - metal-free synthesis - amination - benzylic amines - ethyl pyridinylacetates

Supporting Information

    Supporting information for this article is available online at https://doi.org/10.1055/s-0039-1691587.
  • Supporting Information
 

  • References and Notes

    • 1a Chen C.-Y, Hu W.-P, Yan P.-C, Senadi G.-C, Wang J.-J. Org. Lett. 2013; 15: 6116
      CrossrefPubMed
    • 1b Wang H, Wang Y, Peng C, Zhang J, Zhu Q. J. Am. Chem. Soc. 2010; 132: 13217
      CrossrefPubMed
    • 1c Wolkenberg SE, Wisnoski DD, Leister WH, Wang Y, Zhao Z, Lindsley CW. Org. Lett. 2004; 6: 1453
      CrossrefPubMed
    • 1d Wu XF, Neumann H, Beller M. Chsem. Rev. 2013; 113: 1
    • 1e Vitaku E, Smith DT, Njardarson JT. J. Med. Chem. 2014; 57: 10257
      CrossrefPubMed
    • 2a Kim D, Wang L, Hale JJ, Lynch CL, Budhu RJ, MacCoss M, Mills SG, Malkowitz L, Gould SL, DeMartino JA, Springer MS, Hazuda D, Miller M, Kessler J, Hrin RC, Carver G, Carella A, Henry K, Lineberger J, Schleif WA, Emini EA. Bioorg. Med. Chem. Lett. 2005; 15: 2129
      CrossrefPubMed
    • 2b Alcarazo M, Roseblade SJ, Cowley AR, Fernández R, Brown JM, Lassaletta JM. J. Am. Chem. Soc. 2005; 127: 3290
      CrossrefPubMed
    • 3a Hutt JT, Jo J, Olasz A, Chen C.-H, Lee D, Aron ZD. Org. Lett. 2012; 14: 3162
      CrossrefPubMed
    • 3b Weber MD, Garino C, Volpi G, Casamassa E, Milanesio M, Barolo C, Costa RD. Dalton Trans. 2016; 45: 8984
      CrossrefPubMed
    • 3c Salassa L, Garino C, Albertino A, Volpi G, Nervi C, Gobetto R, Hardcastle KI. Organometallics 2008; 27: 1427
      Crossref
    • 4a Shibahara F, Kitagawa A, Yamaguchi E, Murai T. Org. Lett. 2006; 8: 5621
      CrossrefPubMed
    • 4b Pelletier G, Charette AB. Org. Lett. 2013; 15: 2290
      CrossrefPubMed
    • 4c Mphahlele MJ, Mmonwa MM. Org. Biomol. Chem. 2019; 17: 2204
      CrossrefPubMed
    • 4d Sandoval C, Lim N.-K, Zhang H. Org. Lett. 2018; 20: 1252
      CrossrefPubMed
    • 5a Helan V, Gulevich AV, Gevorgyan V. Chem. Sci. 2015; 6: 1928
      CrossrefPubMed
    • 5b Yang Y, Zhou M.-B, Ouyang X.-H, Pi R, Song R.-J, Li J.-H. Angew. Chem. Int. Ed. 2015; 54: 6595
      CrossrefPubMed
    • 5c Wang Y, Lei X, Tang Y. Chem. Commun. 2015; 51: 4507
      CrossrefPubMed
    • 5d Joshi A, Mohan DC, Adimurthy S. J. Org. Chem. 2016; 81: 9461
      CrossrefPubMed
    • 5e Gulevich AV, Gevorgyan V. Angew. Chem. Int. Ed. 2013; 52: 1371
      CrossrefPubMed
    • 5f Lei X, Li L, He Y.-P, Tang Y. Org. Lett. 2015; 17: 5224
      CrossrefPubMed
    • 5g Miura T, Tanaka T, Matsumoto K, Murakami M. Chem. Eur. J. 2014; 20: 16078
      CrossrefPubMed
    • 5h Park Y, Kim Y, Chang S. Chem. Rev. 2017; 117: 9247
      CrossrefPubMed
    • 5i Li M, Xie Y, Ye Y, Zou Y, Jiang H, Zeng W. Org. Lett. 2014; 16: 6232
      CrossrefPubMed
  • 6 Shi Y, Gulevich AV, Gevorgyan V. Angew. Chem. Int. Ed. 2014; 53: 14191
    CrossrefPubMed
    • 7a Mohan DC, Rao SN, Ravi C, Adimurthy S. Org. Biomol. Chem. 2015; 13: 5602
      CrossrefPubMed
    • 7b Joshi A, Mohan DC, Adimurthy S. Org. Lett. 2016; 18: 464
      CrossrefPubMed
    • 8a Kim HJ, Kim J, Cho SH, Chang S. J. Am. Chem. Soc. 2011; 133: 16382
      CrossrefPubMed
    • 8b Souto JA, Zian D, Muñiz K. J. Am. Chem. Soc. 2012; 134: 7242
      CrossrefPubMed
    • 8c Armstrong A, Collins JC. Angew. Chem. Int. Ed. 2010; 49: 2282
      CrossrefPubMed
    • 8d Pan J, Su M, Buchwald SL. Angew. Chem. Int. Ed. 2011; 50: 8647
      CrossrefPubMed
    • 8e He G, Zhao Y, Zhang S, Lu C, Chen G. J. Am. Chem. Soc. 2012; 134: 3
      CrossrefPubMed
    • 8f Nadres ET, Daugulis O. J. Am. Chem. Soc. 2012; 134: 7
      CrossrefPubMed
  • 9 Inturi SB, Kalita B, Ahamed AJ. Org. Biomol. Chem. 2016; 14: 11061
    CrossrefPubMed
    • 10a Yan Y, Zhang Y, Zha Z, Wang Z. Org. Lett. 2013; 15: 2274
      CrossrefPubMed
    • 10b Yan Y, Zhang Y, Feng C, Zha Z, Wang Z. Angew. Chem. Int. Ed. 2012; 51: 8077
      CrossrefPubMed
  • 11 Qian P, Yan Z, Zhou Z, Hu K, Wang J, Li Z, Zha Z, Wang Z. J. Org. Chem. 2019; 84: 3148
    CrossrefPubMed
    • 12a Song L, Tian X, Lv Z, Li E, Wu J, Liu Y, Yu W, Chang J. J. Org. Chem. 2015; 80: 7219
      CrossrefPubMed
    • 12b Zhang X, Wang P, Yuan X, Qin M, Chen B. Asian J. Org. Chem. 2019; 8: 1332
      Crossref
    • 12c Wang P, Zhang X, Liu Y, Chen B. Asian J. Org. Chem. 2019; 8: 1122
      Crossref
    • 12d Wang Q, Zhang S, Guo F, Zhang B, Hu P, Wang Z. J. Org. Chem. 2012; 77: 11161
      CrossrefPubMed
    • 12e Wu Y.-D, Geng X, Gao Q, Zhang J, Wu X, Wu A.-X. Org. Chem. Front. 2016; 3: 1430
      Crossref
    • 12f Liu X, Wang D, Chen Y, Tang D, Chen B. Adv. Synth. Catal. 2013; 355: 2798
      Crossref
    • 13a Qin M, Tian Y, Guo X, Yuan X, Yang X, Chen B. Asian J. Org. Chem. 2018; 7: 1591
      Crossref
    • 13b Sheng J, Liu J, Zhao H, Zheng L, Wei X. Org. Biomol. Chem. 2018; 16: 5570
      CrossrefPubMed
    • 13c Lamani M, Prabhu KR. J. Org. Chem. 2011; 76: 7938 ; corrigendum: J. Org. Chem. 2011, 76, 9552
      CrossrefPubMed
    • 13d Tang S, Liu K, Long Y, Gao X, Gao M, Lei A. Org. Lett. 2015; 17: 2404
      CrossrefPubMed
    • 13e Wu X, Gao Q, Liu S, Wu A. Org. Lett. 2014; 16: 2888
      CrossrefPubMed
    • 13f Chen Z, Li H, Dong W, Miao M, Ren H. Org. Lett. 2016; 18: 1334
      CrossrefPubMed
    • 14a Arai T, Yokoyama N. Angew. Chem. Int. Ed. 2008; 47: 4989
      CrossrefPubMed
    • 14b Zhang C, De CK, Mal R, Seidel D. J. Am. Chem. Soc. 2008; 130: 416
      CrossrefPubMed
    • 14c Zheng L, Yang F, Dang Q, Bai X. Org. Lett. 2008; 10: 889
      CrossrefPubMed
  • 15 Ethyl 3-Phenylimidazo[1,5-a]pyridine-1-carboxylate (3aa); Typical Procedure A 10-mL Schlenk tube was charged with 1a (0.2 mmol), 2a (1.1 equiv, 0.22 mmol), and I2 (1 equiv, 0.2 mmol). CH2Cl2 (2 mL) was then added and the mixture was stirred at 100 ℃ for 8 h under air. The solvent was removed, and the mixture was filtered and evaporated under vacuum. The residue was purified by column chromatography [silica gel, EtOAc–PE (10:1)] to give a white solid; yield: 88%; mp 127–130 °C. 1H NMR (300 MHz, CDCl3): δ = 8.28 (dd, J = 16.6, 8.2 Hz, 2 H), 7.79 (d, J = 6.6 Hz, 2 H), 7.57–7.46 (m, 3 H), 7.13 (dd, J = 8.9, 6.7 Hz, 1 H), 6.78 (t, J = 6.8 Hz, 1 H), 4.50 (q, J = 7.1 Hz, 2 H), 1.47 (t, J = 7.1 Hz, 3 H). 13C NMR (75 MHz, CDCl3): δ = 163.8, 139.4, 135.6, 129.8, 129.3, 129.2, 129.0, 124.5, 122.7, 121.9, 120.2, 114.7, 60.6, 14.9.