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COMMUNICATION
Journal Name
aryldiazonium salt. The addition of the aryl radical to the
heteroarene produces a radical in the heteroarene structure. The
Acknowledgement
DOI: 10.1039/D0CC01874K
hole of BP takes an electron from radical intermediate and a Ö. Metin thanks to the Turkish Academy of Sciences (TUBA)
for the financial support.
carbocation is formed. Finally, the intermediate is deprotonated to
regenerate the aromaticity and lead to the desired product (Figure
3). To confirm the proposed radical formation via the electron
transfer process in the mechanism, 1,4-benzoquinone and 4-
hydroxy-TEMPO as a radical scavenger were added to the reaction
medium in separate reactions. The reactions are ceased by the
addition of 1,4-benzoquinone or 4-hydroxy-TEMPO and no
corresponding product is yielded (Figure S5). To give further insight
on the mechanism, time-resolved photoluminescence spectroscopy
was performed by imitating the presented catalytic system. The
reduction of lifetime in the presence of the aryldiazonium salt
compared to the pristine BP indicates a photoinduced electron
transfer between the BP and the substrate during the catalytic cycle
(Figure S6).
Notes and references
1
2
3
a) W. Jiang, Y. Li and Z. Wang, Chem. Soc. Rev. 2013, 42, 6113.
b) C. Wang, H. Dong, W. Hu, Y. Liu and D. Zhu, Chem. Rev.
2012, 112, 2208.
a) T. Shiro, T. Fukaya and M. Tobe, Eur. J. Med. Chem. 2015,
97, 397. b) B. Schmidt and D. Geibler, Eur. J. Org. Chem. 2011,
4814.
(a) J. M. Schomaker and T. J. Delia, J. Org. Chem. 2001, 66,
7125. (b) K. S. Yoo, C. H. Yoon and J. M. Jung, J. Am. Chem. Soc.
2006, 128, 16348. (c) Y. C. Jung, R. K. Mishra, C. H. Yoon and
K. W. Jung, Org. Lett. 2003, 5, 2231.
4
5
6
7
8
a) M. Ito, H. Kubo, I. Itani, K. Morimoto, T. Dohi, Y. Kita, J. Am.
Chem. Soc. 2013, 135, 14078. b) M. H. Aukland, M. Šiaučiulis,
A. West, G. J. P. Perry, D. J. Procter, Nat. Catal. 2020, 3, 163.
a) N. R. Deprez and M. S. Sanford, J. Am. Chem. Soc. 2009, 131,
11234. b) H. Kilic, M. Turgut, M. S. Yilmaz and O. Dalkilic, Ö.
Metin, ACS Sust. Chem. Eng. 2018, 6, 11433.
a) C. K. Prier, D. A. Rankic and D. W. C. MacMillan, Chem. Rev.
2013, 113, 5322. b) M. H. Shaw, J. Twilton and D. W. C.
MacMillan, J. Org. Chem. 2016, 81, 6898.
a) A. McNally, C. K. Prier and D. W. C. MacMillan, Science,
2011, 334, 1114. b) P. Kohls, D. Jadhav, G. Pandey and O.
Reiser, Org. Lett. 2012, 14, 672.
a) D. P. Hari, P. Schroll and B. König, J. Am. Chem. Soc. 2012,
134, 2958. b) S. Zhang, Z. Tang, W. Bao, J. Li, B. Guo, S. Huang,
Y. Zhang and Y. Rao, Org. Biomol. Chem. 2019, 17, 4364. (c)
Rybicka-Jasinska, K.; König, B.; Gryko, D. Eur. J. Org. Chem.
2017, 2104.
N2BF4
-
N2
BF4
+ e-
O, S
X=
CB
VB
X
N2BF4
X
radical chain propagation
- e-
X
H
9
a) M. Majek and A. J. Von Wangelin, Angew. Chem. Int. Ed.
2015, 54, 2270. b) T. Xiao, X. Dong, Y. Tang and L. Zhou, Adv.
Synth. Catal. 2012, 354, 3195.
-HBF4
BF4
X
10 J. Liu, H. Wang, J. Bai, T. Li, Y. Yang, Y. Peng and B. Wang, J.
Mater. Chem. A 2017, 5, 24920.
11 X. Ling, H. Wang, S. Huang, F. Xia and M. S. Dresselhaus, Proc.
Natl. Acad. Sci. 2015, 112, 4523.
Figure 3. The plausible reaction mechanism for the BP-catalyzed
direct C-H arylation of furan and thiophene with aryldiazonium salts.
12 a) J. Ran, B. Zhu and S. Z. Qiao, Angew. Chem. Int. Ed. 2017,
56, 10373. b) M. Zhu, C. Zhai, M. Fujitsuka and T. Majima,
Appl. Catal. B Environ. 2018, 221, 645.
13 C. Han, J. Li, Z. Ma, H. Xie, G. I. N. Waterhouse, L. Ye and T.
Zhang, Sci. China Mater. 2018, 61, 1159.
14 a) L. Zhang, L. X. Ding, G. F. Chen, X. Yang and H. Wang, Angew.
Chem. Int. Ed. 2019, 58, 2612. b) Y. T. Liu, D. Li, J. Yu and B.
Ding, Angew. Chem. Int. Ed. 2019, 58, 16439.
15 a) Z. Shen, S. Sun, W. Wang, J. Liu, Z. Liu and J. C. Yu, J. Mater.
Chem. A 2015, 3, 3285. b) Y. Hu, X. Gao, L. Yu, Y. Wang, J. Ning,
S. Xu and X. W. D. Lou, Angew. Chem. 2013, 125, 5746.
16 D. Wang, P. Yi, L. Wang, L. Zhang, H. Li, M. Lu, X. Xie, L. Huang
and W. Huang, Front. Chem. 2019, 7, No. 21.
17 S. Eken Korkut, H. Küçükkeçeci and Ö. Metin, ACS Appl. Mater.
Interfaces 2020, 12, 8130-8139.
18 A. Brown and S. Rundqvist, Acta Cryst. 1965, 19, 684.
19 H. B. Ribeiro, M. A. Pimenta and C. J. S. de Matos, J. Raman
Spec. 2018, 49, 76.
20 a) H. Wang, X. Yang, W. Shao, S. Chen, J. Xie, X. Zhang, J. Wang
and Y. Xie, J. Am. Chem. Soc. 2015, 137, 11376. b) A. Ambrosi,
Z. Sofer and M. Pumera, Angew. Chem. Int. Ed. 2017, 56,
10443.
Conclusions
In conclusion, we have reported for the first time that BP can be
employed as a metal free, visible light active and reusable
heterogeneous photoredox catalyst in the direct C-H arylation of
heteroarenes. The arylation of furan and thiophene with aryl
diazonium salts bearing electron donating and withdrawing groups
was realized smoothly with moderate to good yields under visible-
light irradiation at room temperature. The presented BP-catalyzed C-
H arylation protocol was shown to be applicable for the scale-up
synthesis of heterobiaryl compounds, which is important for the
industrial application. It has further shown that BP can be reused in
the C-H arylation of heteroarenes up to the five cycles without
significant loss of catalytic activity, which is the first example of a
metal free reusable photoredox catalyst that have ever tested in the
C-H activation. Taking advantage of BP as an efficient, metal free,
reusable and low-cost photoredox catalyst, we strongly believe that
this study will open a new avenue in the field of photoredox catalysis
for organic synthesis. In this respect, our studies on the application
of BP and BP-based composites as a photocatalyst for different
organic synthesis are on-going.
21 a) D. Kalyani, K. B. McMurtrey, S. R. Neufeldt and M. S.
Sanford, J. Am. Chem. Soc. 2011, 133, 18566. b) V. Srivastava
and P. P. Singh, RSC Adv. 2017, 7, 31377. (c) Lazarides, T.;
McCormick, T.; Du, P.; Luo, G.; Lindley, B.; Eisenberg, R. J. Am.
Chem. Soc. 2009, 131, 9192.
4 | J. Name., 2012, 00, 1-3
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