À
FULL PAPERS
A First Example of Cobalt-Catalyzed Remote C H Functionalization
[6] For an expanded substrate scope see the more recent
Experimental Section
paper by Xie and co-workers: H. Guo, M. Chen, P.
Jiang, J. Chen, L. Pan, M. Wang, C. Xie, Y. Zhang, Tet-
rahedron 2015, 71, 70.
General Procedure for Cobalt-Catalyzed Nitration
Reactions
[7] See: a) H.-W. Liang, K. Jiang, W. Ding, Y. Yuan, L.
Shuai, Y.-C. Chen, Y. Wei, Chem. Commun. 2015, 51,
16928; b) H. Qiao, S. Sun, F. Yang, Y. Zhu, W. Zhu, Y.
Dong, Y. Wu, X. Kong, L. Jiang, Y. Wu, Org. Lett.
2015, 17, 6086; c) J. Wei, J. Jiang, X. Xiao, D. Lin, Y.
Deng, Z. Ke, H. Jiang, W. Zeng, J. Org. Chem. 2016,
DOI: 10.1021/acs.joc.5b02509; d) J. Xu, C. Shen, X.
Zhu, P. Zhang, M. J. Ajitha, K.-W. Huang, Z. An, X.
Liu, Chem. Asian J. 2016, DOI: 10.1002/asia.201501407.
[8] X.-F. Xia, S.-L. Zhu, Z. Gu, H. Wang, RSC Adv. 2015,
5, 28892.
A 10-mL vial was charged with 0.5 mmol of substrate,
Co(NO3)2·6H2O (29.1 mg, 20 mol%, 0.1 mmol), tert-butyl ni-
trite (TBN) (267 mL, 90%, 4.0 equiv., 2.0 mmol) and 3.5 mL
of acetic acid. The vial was sealed and the reaction stirred at
room temperature for 18 h. After this period the reaction
mixture was diluted with ethyl acetate (30 mL) and extract-
ed using brine (20 mL). The aqueous layer was then extract-
ed with ethyl acetate (230 mL), the organic layers com-
bined, dried over magnesium sulfate and the solvent re-
moved under reduced pressure. The crude reaction mixture
was purified by column chromatography, using dichlorome-
thane as eluent unless stated, providing analytically pure ni-
trated products.
[9] L. Zhu, R. Qiu, X. Cao, S. Xiao, X. Xu, C.-T. Au, S.-F.
Yin, Org. Lett. 2015, 17, 5528.
[10] Note that in ref.[7d] other examples of couplings using
a Cu SET methodology are described; N(SO2Ph)2,
OAc, Br, I and CF3; therefore highlighting the future
1
Full characterization data obtained (including original H,
13C {1H} and COSY NMR spectra for all products and new
compounds) can be found in the Supporting Information.
CCDC 1438116 (11b), CCDC 1438117 (13b) and CCDC
1438118 (15a) contain the supplementary crystallographic
data for this paper. These data can be obtained free of
charge from The Cambridge Crystallographic Data Centre
À
potential for SET C H functionalization methodolo-
gies.
[11] H. Sahoo, M. K. Reddy, I. Ramakrishna, M. Baiyda,
Chem. Eur. J. 2016, 22, 1592.
[12] X. Cong, X. Zeng, Org. Lett. 2014, 16, 3716.
[13] J. Zhou, B. Li, F. Hu, B.-F. Shi, Org. Lett. 2013, 15,
3460.
[14] N. Ono, The Nitro Group in Organic Synthesis, Wiley-
VCH, New York, 2001.
Acknowledgements
[15] G. A. Olah, R. Malhotra, S. C. Narang, Nitration: Meth-
ods and Mechanisms, Wiley-VCH, New York, 1989
[16] a) G. Yan, M. Yang, Org. Biomol. Chem. 2013, 11,
2554; b) G. Yan, A. J. Borah, L. Wang, Org. Biomol.
Chem. 2014, 12, 6049.
[17] For representative examples, see: a) K. I. H. Williams,
S. E. Cremer, F. W. Kent, E. J. Sehm, D. S. Tarbell, J.
Am. Chem. Soc. 1960, 82, 3982; b) M. Nakata, S. Wada,
K. Tatsuta, M. Kinoshita, Bull. Chem. Soc. Jpn. 1985,
58, 1801; c) M. N. Gandy, M. J. Piggot, J. Nat. Prod.
2008, 71, 866.
We acknowledge financial support from the ERC for the
Starting Grant ProjectERC-2011-StG-277801 to X.R and
MINECO of Spain for CTQ2013-43012-P to X.R. and A.C.,
and a RyC contract to A.C. We thank the MECD for a FPU
PhD grant to O.P and Generalitat de Catalunya (2014 SGR
862). X.R. also thanks ICREA for ICREA-Acadmia 2010
and 2015 awards. We are also grateful to X. Fontrodona (X-
ray crystallography), Dr. L. Gómez (HR-MS) and STR-
UdG.
[18] S. Saito, Y. Koizumi, Tetrahedron Lett. 2005, 46, 4715.
[19] B. P. Fors, S. L. Buchwald, J. Am. Chem. Soc. 2009, 131,
12898.
References
[20] For examples of Pd-catalyzed nitration reactions, see:
a) Y.-K. Liu, S.-J. Lou, D.-Q. Xu, Z-Y. Xu, Chem. Eur.
J. 2010, 16, 13590; b) W. Zhang, S. Lou, Y. Liu, Z. Xu,
J. Org. Chem. 2013, 78, 5932; c) J. Dong, B. Jin, P. Sun,
Org. Lett. 2014, 16, 4540; d) W. Zhang, S. Ren, J.
Zhang, Y. Liu, J. Org. Chem. 2015, 80, 5973.
[21] For examples of Cu-catalyzed nitration reactions, see:
a) L. Zhang, Z. Liu, H. Li, G. Fang, B.-D. Barry, T. A.
Belay, X. Bi, Q. Liu, Org. Lett. 2011, 13, 6536; b) J. Liu,
S. Zhuang, Q. Gui, X. Chen, Z. Yang, Z. Tan, Adv.
Synth. Catal. 2015, 357, 732; c) D. Katayev, F. F. Pfister,
T. Wendling, L. J. Gooßen, Chem. Eur. J. 2014, 20,
9902.
[1] J. Recht, E. Ashley, N. White, Safety of 8-Aminoquino-
line Antimalarial Medicines, World Health Organiza-
tion, 2014.
[2] a) J. Yoon, S. A. Wilson, Y. K. Jang, M. S. Seo, K.
Nehru, B. Hedman, K. O. Hodgson, E. Bill, E. I. Solo-
mon, W. Nam, Angew. Chem. 2009, 121, 1283; Angew.
Chem. Int. Ed. 2009, 48, 1257; b) S. Hong, Y.-M. Lee,
K.-B. Cho, K. Sundaravel, J. Cho, M. J. Kim, W. Shin,
W. Nam, J. Am. Chem. Soc. 2011, 133, 11876.
[3] For examples, see: M. Corbet, F. De Campo, Angew.
Chem. 2013, 125, 10080; Angew. Chem. Int. Ed. 2013,
52, 9896.
[22] tert-Butyl nitrate is a known source of nitrogen monox-
ide, see: P. G. Wang, T. B. Cai, N. Taniguchi, in: Nitric
Oxide Donors: for Pharmaceutical and Biological Ap-
plication, (Eds.: P. G. Wang, T. B. Cai, N. Taniguchi),
Wiley-VCH, Weinheim, 2005.
[4] For a review of quinoline functionalization reactions,
see: T. Iwai, M. Sawamura, ACS Catal. 2015, 5, 5031,
and references cited therein.
[5] A. M. Seuss, M. Z. Ertem, C. J. Cramer, S. S. Stahl, J.
Am. Chem. Soc. 2013, 135, 9797.
Adv. Synth. Catal. 2016, 358, 1679 – 1688
ꢀ 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1687