10.1002/adsc.201900261
Advanced Synthesis & Catalysis
various imine-containing dibenzo-[b,d]azepines
through Co(II)-catalyzed regio- and stereo-selective
[5+2] C(Sp2)-H annulation of o-arylanilines with
alkynes via sequential C-C/C-N bond formation. The
reaction features a broad substrate scope and good
functional group tolerances, and both internal alkynes
and terminal alkynes were well tolerated. Preliminary
mechanistic studies suggested that C–H activation is
involved in the rate-determining step.
[6] a) F. Hoffmann-Emery, R. Jakob-Roetne, A. Flohr, F.
Bliss, R. Reentsz, Tetrahedron Lett. 2009, 50, 6380-
6382; b) H. Tabata, H. Suzuki, K. Akiba, H. Takahashi,
H. Natsugari, J. Org. Chem. 2010, 75, 5984-5993; c) X.
Pan, C. S. Wilcox, J. Org. Chem. 2010, 75, 6445-6451;
d) B. S. Bhakuni, A. Kumar, S. J. Balkrishna, J. A.
Sheikh, S. Konar, S. Kumar, Org. Lett. 2012, 14, 2838-
2841; e) T. W. Liwosz, S. R. Chemler, Chem. Eur. J.
2013, 19, 12771-12777; f) T. Saget, N. Cramer, Angew.
Chem., Int. Ed. 2013, 52, 7865-7868; Angew. Chem.
2013, 125, 8019-8022.
Experimental Section
[7] a) Z. Liang, L. Ju, Y. Xie, L. Huang, Y. Zhang, Chem.
Eur. J. 2012, 18, 15816-15821; b) Z. Zuo, J. Liu, J.
Nan, L. Fan, W. Sun, Y. Wang, X. Luan, Angew.
Chem., Int. Ed. 2015, 54, 15385-15389; Angew. Chem.
2015, 127, 15605-15609; c) P. Bai, X.-F. Huang, G.-D.
Xu, Z.-Z. Huang, Org. Lett. 2016, 18, 3058-3061; d) L.
Bai, Y. Wang, Y. Ge, J. Liu, X. Luan, Org. Lett. 2017,
19, 1734-1737.
Typical Procedure for the CoCl2-Catalyzed [5+2] C−H
Annulation of o-Arylanilines with Alkynes
A mixture of 1a (109.7 mg, 0.4 mmol), 2a (142.6 mg, 0.8
mmol), CoCl2 (10.4 mg, 0.08 mmol, 20 mol%), Mn(OAc)2
(13.9 mg, 0.08 mmol, 20 mol%), NaOPiv (113.7 mg, 0.8
mmol, 2.0 eq.) in TFE (3.0 ml) was heated at 120 oC under
O2 (1 atm) for 12 hours. The reaction mixture was cooled
to room temperature, and then the solvent was removed
under vacuum. To the residue, 6 mL of EtOH and NaOH
(64 mg, 1.6 mmol) were added. The mixture was stirred at
75 oC for 6 h, then cooled to room temperature. The
solvent was removed under vacuum and the crude product
was purified by column chromatography on silica gel (n-
hexane/EtOAc = 200:1 to 100:1) to yield 3a (70.6 mg,
65%) as a white solid.
[8] a) A. Lerchen, T. Knecht, C. G. Daniliuc, F. Glorius,
Angew. Chem., Int. Ed. 2016, 55, 15166-15170; Angew.
Chem. 2016, 128, 15391-15395; b) J. H. Kim, S.
Gressies, F. Glorius, Angew. Chem., Int. Ed. 2016, 55,
5577-5581; Angew. Chem. 2016, 128, 5667-5671.
[9] a) L. Ilies, Q. Chen, X. Zeng, E. Nakamura, J. Am.
Chem. Soc. 2011, 133, 5221-5223; b) R. Shang, L. Ilies,
E. Nakamura, J. Am. Chem. Soc. 2015, 137, 7660-7663.
[10] W. Song, L. Ackermann, Angew. Chem., Int. Ed. 2012,
51, 8251-8254; Angew. Chem. 2012, 124, 8376-8379.
Acknowledgements
[11] T. Yoshino, H. Ikemoto, S. Matsunaga, M. Kanai,
Angew. Chem., Int. Ed. 2013, 52, 2207-2211; Angew.
Chem. 2013, 125, 2263-2267.
We thank the National Natural Science Foundation of China
(Nos. 21676253 and 21706234), the Natural Science
Foundation of Zhejiang Province of China (No.
LY19B060011) for financial support.
[12] a) J. Wu, N. Yoshikai, Angew. Chem., Int. Ed. 2016,
55, 336-340; Angew. Chem. 2016, 128, 344-348; b) K.
Gao, N. Yoshikai, Acc. Chem. Res. 2014, 47, 1208-
1219.
References
[13] a) T. T. Nguyen, L. Grigorjeva, O. Daugulis, ACS
Catal. 2016, 6, 551-554; b) L. Grigorjeva, O. Daugulis,
Angew. Chem., Int. Ed. 2014, 53, 10209-10212; Angew.
Chem. 2014, 126, 10373-10376.
[1] B. Zhang, M. Bao, C. Zeng, X. Zhong, L. Ni, Y. Zeng,
X. Cai, Org. Lett. 2014, 16, 6400-6403.
[2] a) J. S. Nair, T. Sheikh, A. L. Ho, G. K. Schwartz,
Anticancer Res. 2013, 33, 1307-1316; b) G. T. Wong,
D. Manfra, F. M. Poulet, Q. Zhang, H. Josien, T. Bara,
L. Engstrom, M. Pinzon-Ortiz, J. S. Fine, H. J. Lee, L.
Zhang, G. A. Higgins, E. M. Parker, J. Biol. Chem.
2004, 279, 12876-12882.
[14] a) S. Maity, R. Kancherla, U. Dhawa, T. Hoque, S.
Pimparkar, D. Maiti, ACS Catal. 2016, 6, 5493-5499;
b) M. Sen, B. Emayavaramban, N. Barsu, J. R.
Premkumar, B. Sundararaju, ACS Catal. 2016, 6,
2792-2796; c) C. Du, P.-X. Li, X. Zhu, J.-F. Suo, J.-L.
Niu, M.-P. Song, Angew. Chem., Int. Ed. 2016, 55,
13571-13575; Angew. Chem. 2016, 128, 13769-13773;
d) J. R. Hummel, J. A. Ellman, J. Am. Chem. Soc.
2015, 137, 490-498; e) P. Patel, S. Chang, ACS Catal.
2015, 5, 853-858; f) A. B. Pawar, S. Chang, Org. Lett.
2015, 17, 660-663.
[3] S. Pegoraro, M. Lang, T. Dreker, J. Kraus, S. Hamm, C.
Meere, J. Feurle, S. Tasler, S. Prüting, Z. Kura, V.
Visan, S. Grissmer, Bioorg. Med. Chem. Lett. 2009, 19,
2299-2304.
[4] W. Phutdhawong, G. Eksinitkun, W. Ruensumran, T.
Taechowisan, W. S. Phutdhawong, Arch. Pharmacal
Res. 2012, 35, 769-777.
[15] For selected reviews of Co-catalyzed C−H activation,
see: a) S. Prakash, R. Kuppusamy, C.-H. Cheng,
ChemCatChem 2018, 10, 683-705; b) N. Sauermann,
T. H. Meyer, L. Ackermann, Chem. Eur. J. 2018, 24,
16209-16217; c) S. M. Ujwaldev, N. A. Harry, M. A.
Divakara, G. Anilkumar, Catal. Sci. Technol. 2018, 8,
5983-6018; d) S. Wang, S.-Y. Chen, X.-Q. Yu, Chem.
[5] R. Rajagopalan, A. Bandyopadhyaya, D. R.
Rajagopalan, P. Rajagopalan, Bioorg. Med. Chem. Lett.
2014, 24, 576-579.
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