Organic Letters
Letter
molecule of I to deliver intermediate III. Finally, the internal
nucleophilic addition to the oxocarbenium ion occurs to give
the final annulation product 3a and releases the gold catalyst.
Another possibility is that the reaction of I with another
molecule of 2a would yield intermediate IV, which would
undergo a formal [4 + 4] cycloaddition with 1a to form 3a
directly. However, since IV is very easily undergoing an
intramolecular [2 + 2] annulation to form four-membered
product 5. Thus, the [4 + 4] pathway is less possible. The
diastereoselectivity of this cyclization, in which the two alkenes
are in a (3E,5Z)-configuration, is because the preferential
formation of II than II′.15 Also, the subsequential addition of
II to I would favor the formation of III over sterically hindered
III′.
Author Contributions
†C.W. and G.X. contributed equally to this work
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
We thank the NSFC (No. 21971026) and the Jiangsu Key
Laboratory of Advanced Catalytic Materials & Technology
(BM2012110) for their financial support.
REFERENCES
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ASSOCIATED CONTENT
* Supporting Information
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CCDC 2011084 contains the supplementary crystallographic
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AUTHOR INFORMATION
Corresponding Author
̈
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́
́
̃
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Jiangtao Sun − Jiangsu Key Laboratory of Advanced Catalytic
Materials & Technology, School of Petrochemical Engineering,
Changzhou University, Changzhou 213164, China;
́
A.; Mascarenas, J. L.; Lopez, F.; Ujaque, G. Chem. - Eur. J. 2013, 19,
̃
15248. (d) Pirovano, V.; Decataldo, L.; Rossi, E.; Vicente, R. Chem.
Commun. 2013, 49, 3594.
(5) De, N.; Song, C. E.; Ryu, D. H.; Yoo, E. J. Chem. Commun. 2018,
54, 6911.
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Authors
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as,
́
J. L.; Lopez, F. Angew. Chem., Int. Ed. 2013, 52, 6526. (b) Faustino,
Cheng Wang − Jiangsu Key Laboratory of Advanced Catalytic
Materials & Technology, School of Petrochemical Engineering,
Changzhou University, Changzhou 213164, China
Guangyang Xu − Jiangsu Key Laboratory of Advanced Catalytic
Materials & Technology, School of Petrochemical Engineering,
Changzhou University, Changzhou 213164, China
Ying Shao − Jiangsu Key Laboratory of Advanced Catalytic
Materials & Technology, School of Petrochemical Engineering,
Changzhou University, Changzhou 213164, China;
Shengbiao Tang − Jiangsu Key Laboratory of Advanced
Catalytic Materials & Technology, School of Petrochemical
Engineering, Changzhou University, Changzhou 213164,
China
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(7) Peng, S.; Ji, D.; Sun, J. Chem. Commun. 2017, 53, 12770.
(8) Donald, J. R.; Unsworth, W. P. Chem. - Eur. J. 2017, 23, 8780.
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