10.1002/ejoc.202001535
European Journal of Organic Chemistry
COMMUNICATION
aromatic 1-tetralones. The effect of different substituents on
the cyclobutanol as well as on the aromatic/heteroaromatic
core was also evaluated. Based on our studies, we found
that most substrates containing electron-donating groups
and mildly electron-withdrawing substituents could ring-
expand under direct anodic expansion conditions. Substrates
with strongly electron-withdrawing substituents exhibited
elevated oxidation potentials and required the addition of a
manganese catalyst for successful ring expansion to occur.
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M. C. Leech, A. D. Garcia, A. Petti, A. P. Dobbs
and K. Lam, React. Chem. Eng., 2020, 5, 977–990.
M. Yan, Y. Kawamata and P. S. Baran, Angew.
Chemie Int. Ed., 2018, 57, 4149–4155.
R. Francke and R. D. Little, Chem. Soc. Rev., 2014,
43, 2492.
A. D. Garcia, M. C. Leech, A. Petti, C. Denis, I. C.
A. Goodall, A. P. Dobbs and K. Lam, Org. Lett.,
2020, acs.orglett.0c01324.
Acknowledgements
14
E. J. Horn, B. R. Rosen, Y. Chen, J. Tang, K. Chen,
M. D. Eastgate and P. S. Baran, Nature, 2016, 533,
77–81.
The authors gratefully acknowledge an EPSRC Imperial
College President’s Scholarship (to P.N.) and additional
funding from Dr Isabel Bader and her late husband Dr Alfred
Bader (to P.J.P.), Oxana Bennett (to P.J.P.), the University of
Greenwich Vice Chancellor’s PhD Scholarship (to A.P.), the
Engineering and Physical Sciences Research Council (Grant
EP/S017097/1 to K.L.) and IKA for their material support (to
K.L.). The authors thank Dr Lewis Allen for proofreading this
article and Dr Matthew Leech for help with cyclic
voltammetry studies. The authors also wish to thank Pete
Haycock and Dr Lisa Haigh for NMR and mass spectrometric
analysis at Imperial College London, Dr Iain Goodall and
Victoria Elmes for mass spectrometric and NMR analysis at
the University of Greenwich, respectively. The authors
dedicate this work to the late Horst Natho.
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M. Quertenmont, I. Goodall, K. Lam, I. Markó and
O. Riant, Org. Lett., 2020, 22, 1771–1775.
Y. Takahira, M. Chen, Y. Kawamata, P. Mykhailiuk,
H. Nakamura, B. K. Peters, S. H. Reisberg, C. Li, L.
Chen, T. Hoshikawa, T. Shibuguchi and P. S. Baran,
Synlett, 2019, 30, 1178–1182.
17
J. C. Kang, Y. Q. Tu, J. W. Dong, C. Chen, J. Zhou,
T. M. Ding, J. T. Zai, Z. M. Chen and S. Y. Zhang,
Org. Lett., 2019, 21, 2536–2540.
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H. I. Jung, Y. Kim and D. Y. Kim, Org. Biomol.
Chem., 2019, 17, 3319–3323.
Keywords: electrocatalysis • ring expansion • cyclobutanols •
metal-free catalysis • tetralones
Y. J. Kim and D. Y. Kim, Org. Lett., 2019, 21,
1021–1025.
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