Advanced Synthesis & Catalysis
10.1002/adsc.201800684
(
thq) leaving large space for late stage N-
[5] F. Yang, J. Li, J. Xie and Z. Z. Huang, Org. Lett. 2010,
12, 5214.
functionalizations as well as at indole N-H. The
reaction prevented undesirable homocoupling,
enamine tautomerisation and aromatization, thus
[
[
6] O. Basle and C. J. Li, Green Chem. 2007, 9, 1047.
3
2
affording exclusively C(sp )-C(sp ) coupling products.
The open air reaction proceeds with abundant,
inexpensive copper catalyst under aqueous conditions.
The reaction is highly step and atom economic under
easy to operate conditions.
7] K. H. He, F. F. Tan, C. Z. Zhou, X. L. Yang and Y. Li,
Angew. Chem. Int. Ed. 2017, 56, 3080.
[8] a) S. Minakata, Y. Ohshima, A. Takemiya, I. Ryu, M.
Komatsu, Y. Ohshiro, Chem. ett. 1997, 311; b) G. H.
Kerr, O. M. Cohn, E. B. Mullock, H. Suschitzky, J.
Chem. Soc. Perkin Trans. 1 1974, 1614.
Experimental Section
[
9] a) A. T. Soldatenkov, K. B. Polyanskii, N. M.
Kolyadina, S. A. Soldatova, Chem. Heterocycl. Compd.
General procedure for the copper catalyzed direct
oxidative CDC reaction between tetrahydroquinoline 1
and indole derivatives 2:
2
009, 45, 633. b) T. Izumi, K. Kohei, S. Murakami, J.
Heterocycl. Chem. 1993, 30, 1133. c) S. I. Murahashi,
T. Oda, T. Sugahara, Y. Masui, J. Org. Chem. 1990, 55,
A mixture of tetrahydroquinoline 1 (2 mmol), indoles (1
mmol) and CuI (0.1 mmol, 10 mol %) in water (2 mL)
solvent was stirred at 60 °C under open air until the
reaction was completed. Subsequently, the reaction
mixture was allowed to cool to room temperature and
extracted with ethylacetate. The organic layer was dried
1
4
2
744. d) A. V. Iosub and S. S. Stahl Org. Lett. 2015, 17,
404. e) D. Jung, M. H. Kim and J. Kim, Org. Lett.
016, 18, 6300.
[
10] Z. Tan, H. Jaing and M. Zhang, Org. Lett. 2016, 18,
over anhydrous Na
2
SO
4
and then solvent was removed
3174.
under reduced pressure. Finally, the resulting mixture was
concentrated under vacuum and the residue was purified
by column chromatography (silica gel, petroleum
ether/ethyl acetate as an eluent) to afford the desired
coupling products 3.
[11] G. Li and H. Nakamura, Angew. Chem. Int. Ed. 2016,
5, 6758.
5
[
12] Y Miyake, K. Nakajima and Y. Nishibayashi, Chem.
Eur. J. 2012, 18, 16473.
Acknowledgements
[
13] a) M. Chandrasekharam, B. Chiranjeevi, K. S. V.
Gupta, B. Sridhar, J. Org. Chem. 2011, 76, 10229. b) B.
Chiranjeevi, B. Vinayak, T. Parsharamulu, V. S.
Phanibabu, B. Jagadeesh, M. Chandrasekharam, Eur. J.
Org. Chem. 2014, 2014, 7839. c) K. S. V. Gupta, D. V.
Ramana, B. Vinayak, B. Sridhar, M. Chandrasekharam,
New J. Chem. 2016, 40, 6389. d) D. V. Ramana, L. R.
Chowhan and M. Chandrasekharam, ChemistrySelect
D.V.R thanks University Grants Commission (UGC), New Delhi,
India for the Senior Research Fellowship (SRF).
References
[
1] a) V. Sridharan, P. A. Suryavanshi, J. C. Menendez,
Chem. Rev. 2011, 111, 7157. b) J. D. Scott, R. M.
Williams, Chem. Rev. 2002, 102, 1669. c) V. H. Le, M.
Inai, R. M. Williams, T. Kan, Nat. Prod. Rep. 2015, 32,
2
017, 2, 2241. e) R. V. Daggupati, C. Malapaka, Org.
Chem. Front. 2018, 5, 788.
[14] X. Chen, H. Zhao, C. Chen, H. Jiang, M. Zhang, Org.
Lett. 2018, 20, 1171.
3
28. d) D. S. Wang, Q. A. Chen, S. M. Lu, Y. G. Zhou,
Chem. Rev. 2012, 112, 2557.
[
15] a) M. Ghobrial, M. Schnurch and M. D. Mihovilovic,
J. Org. Chem. 2011, 76, 8781. b) H. Zhao, X. Chen, H.
Jianga and M. Zhang, Org. Chem. Front. 2018, 5, 539.
[
[
2] M. Somei and F. Yamada, Nat.Prod.Rep., 2005, 22, 73.
3] a) T. Huang, X. Liu, J. Lang, J. Xu, L. Lin and X. Feng
ACS Catal. 2017, 7, 5654. b) W. Liu, S. Liu, R. Jin, H.
Guo and J. Zhao, Org. Chem. Front. 2015, 2, 288. c) G.
Oss, S. D. D. Vos, K. N. H. Luc, J. B. Harper, and T.
V. Nguyen, J. Org. Chem. 2018, 83, 1000. d) M.
Ghobrial, K. Harhammer, M. D. Mihovilovica and M.
Schnürch, Chem. Commun., 2010, 46, 8836. e) M. L.
Deb, C. D. Pegu, P. J. Borpatra, P. J. Saikiab and P. K.
Baruah, Green Chem. 2017, 19, 4036. f) T. Punirun, D.
Soorukram, C. Kuhakarn, V. Reutrakul and M.
Pohmakotr, J. Org. Chem. 2018, 83, 765. g) J.
Dhineshkumar, P. Samaddar and K. R. Prabhu, ACS
Omega, 2017, 2, 4885. h) Q. H. Zheng, W. Meng, G. J.
Jiang and Z. X. Yu, Org. Lett. 2013, 15, 5928. i) M.
Ghobrial, M. Schnürch and M. D. Mihovilovic, J. Org.
Chem. 2011, 76, 8781. j) K. Alagiri, G. S. R. Kumara
and K. R. Prabhu, Chem. Commun. 2011, 47, 11787.
[
4] Z. Li and C. J. Li, J. Am. Chem. Soc. 2005, 127, 6968.
4
This article is protected by copyright. All rights reserved.