3
a Reagents and conditions: arylboronic acid 1 (1 mmol), PdCl2 (0.03 mmol), Bu4NBr (0.2 mmol), 10.5% aqueous NaClO (3 mL), 12-24 h. b Isolated yield after
column chromatography.
3. (a) Yasamut, K.; Jongcharoenkamol, J.; Ruchirawat, S.;
Ploypradith, P. Tetrahedron. 2016, 72, 5994; (b) Dumbre, D.;
Choudhary, V. R.; Selvakannan, P. R. Polyhedron. 2016, 120,
180; (c) Park, B. R.; Kim, K. H.; Kim, T. H.; Kim, J. N.
Tetrahedron Lett. 2011, 52, 4405; (d) Hassan, J.; Hathroubi, C.;
Although the mechanism of the presented reaction was not
examined in detail, based on experimental results and work
reported in the literature,9e,10d,11 a probable mechanism was
proposed (Scheme 2). Firstly, arylboronic acid reacts with PdCl2
to form the Ar–Pd(II)–Ar intermediate and boric acid by
oxidation. Subsequently, the Pd(II) intermediate undergoes
reductive elimination to form the biaryl product as well as Pd(0).
Finally, Pd(0) is oxidized by NaClO into Pd(II).
Gozzi, C.; Lemaire, M. Tetrahedron Lett. 2000, 41, 8791.
4. (a) Heidari, F.; Hekmati, M.; Veisi, H. J. Colloid Interface Sci.
2017, 501, 175; (b) Baran, T.; Sargin, I.; Kaya, M.; Menteş, A. J.
Mol. Catal. A: Chem. 2016, 420, 216; (c) Al-Masoudi, N. A.;
Kadhim, R. A.; Abdul-Rida, N. A.; Saeed, B. A.; Engel, M.
Steroids. 2015, 101, 43; (d) Luo, Z.; Xiong, L.; Liu, T.; Zhang, Y.;
Lu, S.; Chen, Y.; Guo, W.; Zhu, Y.; Zeng, Z. J. Org. Chem. 2019,
84, 10559; (e) Xia, W.; Zhang, Z. W.; Li, Y.; Jiang, X.; Liang, H.;
Zhang, Y.; Cao, R.; Qiu, L. Org. Biomol. Chem. 2019, 17, 2351.
5. Chang, S.; Dong, L. L.; Song, H. Q.; Feng, B. Org. Biomol. Chem.
2018, 16, 3282.
6. (a) Hajipour, A. R.; Abolfathi, P. Catal. Commun. 2018, 103, 92;
(b) Lee, W. S.; Byun, S.; Kwon, J.; Kim, B. M. Bull. Korean
Chem. Soc. 2016, 37, 1992; (c) Feiz, A.; Loni, M.; Naderi, S.;
Bazgir, A. Appl. Organomet. Chem. 2018, 32, e4608.
7. (a) Chaudhari, K. R.; Wadawale, A. P.; Jain, V. K. J. Organomet.
Chem. 2012, 698, 15; (b) Xu, C.; Yin, L.; Huang, B.; Liu, H.; Cai,
M. Tetrahedron. 2016, 72, 2065; (c) Jadhav, B. D.; Pardeshi, S. K.
Appl. Organomet. Chem. 2017, 31, e3591.
8. (a) Susanto, W.; Chu, C. Y.; Ang, W. J.; Chou, T. C.; Lo, L. C.;
Lam, Y. J. Org. Chem. 2012, 77, 2729; (b) Lipschutz, M. I.;
Tilley, T. D. Angew. Chem. Int. Ed. 2014, 53, 7290; (c) Nair, A.
G.; McBurney, R. T.; Gatus, M. R. D.; Walker, D. B.; Bhadbhade,
M.; Messerle, B. A. J. Organomet. Chem. 2017, 845, 63.
9. (a) Zhao, H.; Mao, G.; Han, H.; Song, J.; Liu, Y.; Chu, W.; Sun,
Z. RSC Adv. 2016, 6, 41108; (b) Cao, Y. N.; Tian, X. C.; Chen, X.
X.; Gao, F.; Zhou, X. L. Synlett. 2017, 27, 601; (c) Lee, D, S.;
Cho, E. J. Org. Biomol. Chem. 2019, 17, 4317; (d) Ostrowska, S.;
Rogalski, S.; Lorkowski, J.; Walkowiak, J.; Pietraszuk, C. Synlett.
2018, 29, 1735; (e) Raul, P. K.; Mahanta, A.; Bora, U.; Thakur, A.
J.; Veer, V. Tetrahedron Lett. 2015, 56, 7069; (f) Agrahari, B.;
Layek, S.; Kumari, S.; Anuradha, G. R.; Pathak, D. D. J. Mol.
Struct. 2017, 1134, 85; (g) Valiente, A.; Carrasco, S.; Sanz-Marco,
A.; Tai, C. W.; Bermejo, G. A.; Martin-Matute, B. Chem. Cat.
Chem. 2019, 11, 3933.
10. (a) Dwivedi, S.; Bardhan, S.; Ghosh, P.; Das, S. RSC Adv. 2014, 4,
41045; (b) Mao. J.; Hua, Q.; Xie, G.; Yao, Z.; Shi, D. Eur. J. Org.
Chem. 2009, 14, 2262; (c) Puthiaraj, P.; Suresh, P.; Pitchumani, K.
Green Chem. 2014, 16, 2865; (d) Wang, Y. H.; Xu, M. C.; Liu, J.;
Zhang, L. J.; Zhang, X. M. Tetrahedron. 2015, 71, 9598.
Scheme 2. Proposed mechanism for the homocoupling reaction.
In conclusion, we have developed a simple and efficient
method for the synthesis of symmetrical biphenyls via the
oxidative homocoupling reactions of arylboronic acids catalyzed
by PdCl2 in aqueous NaClO. This protocol is applicable to a wide
variety of arylboronic acids bearing electron-donating as well as
electron-withdrawing groups. An investigation of the Pd-
catalyzed asymmetric version of this reaction is undergoing and
will be reported in due course.
Acknowledgments
This work was financially supported by the National Natural
Science Foundation of China (81560620), the Yunnan Provincial
Science and Technology Department-Applied Basic Research
Joint Special Funds of Yunnan University of Chinese Medicine
(2017FF117(-023)).
Appendix A. Supplementary data
11. Mulla, S. A. R.; Chavan, S. S.; Pathan, M. Y.; Inamdar, S. M.;
Shaikh, T. M. Y. RSC Adv. 2015, 5, 24675.
Supplementary data to this article can be found online at
References and notes
1. (a) Ingoglia, B. T.; Wagen, C. C.; Buchwald, S. L. Tetrahedron.
2019, 75, 4199; (b) Tague, A. J.; Putsathit, P.; Hutton, M. L.;
Hammer, K. A.; Wales, S. M.; Knight, D. R.; Riley, T. V.; Lyras,
D.; Keller, P. A.; Pyne, S. G. Eur. J. Med. Chem. 2019, 170, 203;
(c) Webster, A. M.; Cobb, S. L. Tetrahedron Lett. 2017, 58, 1010;
(d) Dherbassy, Q.; Wencel-Delord, J.; Colobert, F. Tetrahedron.
2018, 74, 6205.
2. (a) Baran, T. J. Mol. Struct. 2017, 1141, 535; (b) Vasconcelos, S.
N. S.; Reis, J. S.; Oliveira, L. M.; Balfour, M. N.; Stefani, H. A.
Tetrahedron. 2019, 75, 1865; (c) Badekai, P. I. A; Bhat, B. J. Mol.
Catal. A: Chem. 2012, 358, 73; (d) Baran, Y.; Baran, T.; Menteş,
A. Appl. catal. A: Gener. 2017, 531, 36.