Download PDF
Synthesis
DOI: 10.1055/a-2288-6944
paper
Special Issue PSRC-10 (10th Pacific Symposium on Radical Chemistry)

A Photochemical Strategy for the Synthesis of Caprolactams via Dearomative Ring Expansion of Nitroarenes

Raquel Sánchez-Bento 
a   Department of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
,
Linda Bui
b   Institute of Organic Chemistry, RWTH Aachen University, 52056 Aachen, Germany
,
Vincent K. Duong
a   Department of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
,
Alessandro Ruffoni∗
b   Institute of Organic Chemistry, RWTH Aachen University, 52056 Aachen, Germany
,
Daniele Leonori∗
b   Institute of Organic Chemistry, RWTH Aachen University, 52056 Aachen, Germany
› Author AffiliationsR.S.-B. thanks the European Union Horizon 2020 innovation programme for a Marie Skłodowska-Curie grant, agreement no. 956324 (PhotoReAct).
› Further Information
    Permissions and Reprints All articles of this category


Abstract

This paper outlines a novel strategy for the preparation of seven-membered-ring lactams from simple nitroarenes. The approach is based on a photochemical dearomative ring expansion starting with the conversion of the nitro group into a singlet nitrene. This process is mediated by blue light, occurs at room temperature and overall enables the insertion of the nitro N-atom into the benzenoid framework. This step transforms the aromatic starting material into a seven-membered ring azepine that, following hydrogenation and hydrolysis, is converted into the desired caprolactams in just three steps.

Key words

singlet nitrene - photoexcited nitroarenes - ring expansion - azepines - hydrogenation - caprolactams - N-insertion

Supporting Information

    Supporting information for this article is available online at https://doi.org/10.1055/a-2288-6944.
  • Supporting Information


Publication History

Received: 15 February 2024

Accepted after revision: 15 March 2024

Accepted Manuscript online:
15 March 2024

Article published online:
02 April 2024

© 2024. Thieme. All rights reserved

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany

 

  • References

  • 1 Llarrull LI, Testero SA, Fisher JF, Mobashery S. Curr. Opin. Microbiol. 2010; 13: 551
  • 2 Caruano J, Muccioli GG, Robiette R. Org. Biomol. Chem. 2016; 14: 10134
  • 3 Saldívar-González FI, Lenci E, Trabocchi A, Medina-Franco JL. RSC Adv. 2019; 9: 27105
  • 4 Perry CM. Am. J. Cardiovasc. Drugs 2012; 12: 415
  • 5 Kumar R, Shah S, Paramita Das P, Bhagavanbhai GG. K, Al Fatesh A, Chowdhury B. Catal. Rev.: Sci. Eng. 2019; 61: 516
  • 6 Chandrasekhar S. Compr. Org. Synth. 2014; 7: 770
  • 7 Chenault HK. Synthesis of Pyrrolidones and Caprolactams by Ring Modification or Multi-component Ring-Forming Reaction. In Handbook of Pyrrolidone and Caprolactam Based Materials, Vol. 1, Chap. 3. Musa OM. John Wiley & Sons Ltd; Weinheim: 2021
    Google Scholar
  • 8 Komatsu N, Simizu S, Sugita T. Synth. Commun. 1992; 22: 277
  • 9 Rasouli MA, Mahdavi M, Rashidi Ranjbar P, Saeedi M, Shafiee A, Foroumadi A. Tetrahedron Lett. 2012; 53: 7088
  • 10 Alonso DA, Falvello LR, Mancheño B, Nájera C, Tomás M. J. Org. Chem. 1996; 61: 5004
  • 11 Chen Y, Du J, Zuo Z. Chem 2020; 6: 266
  • 12 Peixoto D, Malta G, Cruz H, Barroso S, Carvalho AL, Ferreira LM, Branco PS. J. Org. Chem. 2019; 84: 3793
  • 13 Babu GV. S, Bhaskaran A, Sridhar B, Rao TV, Parvathaneni SP. ChemistrySelect 2021; 6: 5
  • 14 Mykura R, Sánchez-Bento R, Matador E, Duong VK, Varela A, Angelini L, Carbajo RJ, Llaveria J, Ruffoni A, Leonori D. Nat. Chem. 2024; in press DOI: 10.1038/s41557-023-01429-1.
  • 15 Testa AC. J. Phys. Chem. 1975; 79: 644
  • 16 Gritsan NP, Platz MS. Chem. Rev. 2006; 106: 3844
    • 17a DeGraff BA, Gillespie DW, Sundberg RJ. J. Am. Chem. Soc. 1974; 96: 7491
    • 17b Huisgen R, Vossius D, Appl M. Chem. Ber. 1958; 91: 1
  • 18 Chapman O, Roux J.-P. J. Am. Chem. Soc. 1978; 100: 282
  • 19 Satake K, Okuda R, Hashimoto M, Fujiwara Y, Watadani I, Okamoto H, Kimura M, Morosawa S. J. Chem. Soc., Chem. Commun. 1991; 1154
  • 20 Negele S, Wieser K, Severin T. J. Org. Chem. 1998; 63: 1138
  • 21 Lavinda O, Witt CH. Angew. Chem. Int. Ed. 2022; 61: e202114183
  • 22 Overberger CG, Kozlowski JH, Radlmann E. J. Polym. Sci., Part A-1: Polym. Chem. 1972; 10: 2265
  • 23 Chen M, Dong G. J. Am. Chem. Soc. 2017; 139: 7757
  • 24 Reimschuessel HK, Sibilia JP. J. Org. Chem. 1969; 34: 959
  • 25 Denmark SE, Xie M. J. Org. Chem. 2007; 72: 7050
  • 26 Kitagawa O, Velde DV, Dutta D, Morton M, Takusagawa F, Aubé J. J. Am. Chem. Soc. 1995; 117: 5169