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ARTICLE
Journal Name
A
There are no conflicts to declare.
DOI: 10.1039/D0GC03892J
OH
B
N
O
nBu NPF , DMF, TFA, 80 °C
N
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4
6
Acknowledgements
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N
2
N
3
undivided cell,10 mA/cm , 8 h
We are grateful to the National Natural Science Foundation of China
21732002, 22077071) for generous financial support for our
2
eq BHT
NR
(
programs.
B
OH
Notes and references
N
B
nBu4NPF6, DMF, TFA, 80 °C
OH
O
O
2
1. C. Chatgilialoglu., A. Studer., Encyclopedia of Radicals in
Chemistry, Biology and Materials, Wiley, Chichester, 2012.
undivided cell,10 mA/cm , 8 h
N
2
. R. S. J. Proctor, R. J. Phipps, Angew. Chem., Int. Ed. 2019, 58,
3666-13699.
Based on the above-described experimental results, we propose 3. a) A. Fawcett, J. Pradeilles, Y. Wang, T. Mutsuga, E. L. Myers,
2
9, 8%
1
the reaction mechanism outlined in Scheme 7. Single-electron
oxidation of the boronic compound at the anode generates an alkyl
radical, which reacts with the protonated heteroarene to give
radical cation I. Then the radical cation loses a proton to give C-
radical intermediate II. Finally, II undergoes single-electron
oxidation at the anode to give the product.
V. K. Aggarwal, Science 2017, 357, 283-286; b) C. Li, J. Wang,
L. M. Barton, S. Yu, M. Tian, D. S. Peters, M. Kumar, A. W. Yu,
K. A. Johnson, A. K. Chatterjee, M. Yan, P. S. Baran, Science
2
017, 356, 1045; c)J. W. B. Fyfe, A. J. B. Watson, Chem 2017,
3, 31-55.
4
5
. D. B. Diaz, A. K. Yudin, Nat Chem 2017, 9, 731-742.
. a) W. Liu, P. Liu, L. Lv, C. J. Li, Angew. Chem., Int. Ed. 2018, 57,
1
3499-13503; b) Y. Cheng, C. Muck-Lichtenfeld, A. Studer,
Scheme 7. Proposed mechanism
Angew. Chem., Int. Ed. 2018, 57, 16832-16836
. J. K. Matsui, D. N. Primer, G. A. Molander, Chem. Sci. 2017, 8,
3512-3522.
6
7
8
9
e
e
. Y. Fujiwara, V. Domingo, I. B. Seiple, R. Gianatassio, M. Del
Bel, P. S. Baran, J. Am. Chem. Soc. 2011, 133, 3292-3295.
. A. S. Demir, O. Reis, M. Emrullahoglu, J. Org. Chem. 2003, 68,
R
B(OH)2
5
78-580.
R
R
BK3F
Bpin
. G. Sorin, R. Martinez Mallorquin, Y. Contie, A. Baralle, M.
Malacria, J. P. Goddard, L. Fensterbank, Angew. Chem., Int.
Ed. 2010, 49, 8721-8723.
oxidation
N
O
1
0. L. Zhang, Z. Q. Liu, Org. Lett. 2017, 19, 6594-6597.
N
H
H2
11. G. X. Li, C. A. Morales-Rivera, Y. Wang, F. Gao, G. He, P. Liu, G.
R
Chen, Chem. Sci. 2016, 7, 6407-6412.
1
2. F. Lima, U. K. Sharma, L. Grunenberg, D. Saha, S. Johannsen, J.
Sedelmeier, E. V. Van der Eycken, S. V. Ley, Angew. Chem.,
Int. Ed. 2017, 56, 15136-15140.
N
O
R
1
3. M. Yan, Y. Kawamata, P. S. Baran, Chem. Rev. 2017, 117,
N
1
3230-13319.
H
1
1
4. S. Inagi, T. Fuchigami, Curr Opin Electrochem 2017, 2, 32-37.
5. H. Yan, Z. W. Hou, H. C. Xu, Angew. Chem., Int. Ed. 2019, 58,
4592-4595.
I
N
O
R
H+
-
1
1
6. Y. Yuan, Y. Zheng, B. Xu, J. Liao, F. Bu, S. Wang, J.-G. Hu, A.
Lei, ACS Catal. 2020, 10, 6676-6681.
7. a) J. Dong, Z. Wang, X. Wang, H. Song, Y. Liu, Q. Wang,
Science Advances 2019, 5: eaax9955. b) K. Niu, L. Song, Y.
Hao, Y. Liu, Q. Wang, Chem. Commun., 2020, 56, 11673-
11676
2H+
N
H
II
oxidation
-H+
N
O
N
O
R
1
8. a) R. R. Gupta, Bioactive heterocycles V, Topics in
Heterocyclic Chemistry V, ed. R. R. Gupta, Wiley-VCH,
Springer, Heidelberg, Hoboken, vol. 11, 2008; b) S. W.
Thomas III, G. D. Joly and T. M. Swager, Chem. Rev., 2007,
N
R
N
H
Conclusions
1
07, 1339.
In summary, we have developed a protocol for electro-oxidative C–
H alkylation reactions of quinoxalin-2(1H)-ones with organoboron
compounds. Organoboronic acids, trifluoroborates, and even
boronic esters could be converted into alkyl radicals by direct
electrochemical oxidation without the need for a metal, an oxidant,
or a photoredox reagent. Further studies utilizing alkyl radicals
generated from organoboron compounds are underway in our
laboratory.
1
9. W. Zhao, R. P. Wurz, J. C. Peters, G. C. Fu, J. Am. Chem. Soc.
2017, 139, 12153-12156.
Conflicts of interest
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