Organic Letters
Letter
W.; Liu, X.; Chen, E.; Chen, B.; Shao, J.; Yu, Y. Org. Chem. Front. 2017, 4,
1162.
group-stabilizing strategy. A variety of β-functionalized N-
unprotected enamines, including β-nitro, acyl, and sulfonyl, can
be prepared by this approach in a stereoselective manner, thus
providing a general route to access this kind of functionalized
alkenes. An unusual 1,3-H transfer was disclosed on the basis of
experimental results and DFT calculations. This strategy
represents an appealing means to achieve N-unprotected
enamine synthesis; extension to other radical species is under
way, and will be reported in due course.
(9) (a) Xu, H.-D.; Zhou, H.; Pan, Y.-P.; Ren, X.-T.; Wu, H.; Han, M.;
Han, R.-Z.; Shen, M.-H. Angew. Chem., Int. Ed. 2016, 55, 2540.
(b) Farney, E. P.; Yoon, T. P. Angew. Chem., Int. Ed. 2014, 53, 793.
(10) (a) Gao, P.; Wang, J.; Bai, Z.-J.; Shen, L.; Yan, Y.-Y.; Yang, D.-S.;
Fan, M.-Z.; Guan, Z.-H. Org. Lett. 2016, 18, 6074. (b) Sun, X.; Lyu, Y.;
Zhang-Negrerie, D.; Du, Y.; Zhao, K. Org. Lett. 2013, 15, 6222. (c) Liu,
X.; Cheng, R.; Zhao, F.; Zhang-Negrerie, D.; Du, Y.; Zhao, K. Org. Lett.
2012, 14, 5480.
(11) (a) Zhou, M.; Xue, Z.; Cao, M.; Dong, X.-Q.; Zhang, X. Org.
Biomol. Chem. 2016, 14, 4582. (b) Hsiao, Y.; Rivera, N. R.; Rosner, T.;
Krska, S. W.; Njolito, E.; Wang, F.; Sun, Y.; Armstrong, J. D., III;
Grabowski, E. J. J.; Tillyer, R. D.; Spindler, F.; Malan, C. J. Am. Chem. Soc.
2004, 126, 9918.
(12) Stanovnik, B.; Svete, J. Chem. Rev. 2004, 104, 2433.
(13) Rabet, P. T. G.; Boyd, S.; Greaney, M. F. Angew. Chem., Int. Ed.
2017, 56, 4183 and reference cited therein.
ASSOCIATED CONTENT
* Supporting Information
The Supporting Information is available free of charge on the
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S
Experimental procedures and spectra copies (PDF)
(14) For examples of radical addition to vinyl azides, see: (a) Sun, X.;
Yu, S. Chem. Commun. 2016, 52, 10898. (b) Mackay, E. G.; Armido, S.
Chem. - Eur. J. 2016, 22, 13455. (c) Liu, K.; Chen, S.; Li, X.; Liu, P. J. Org.
Chem. 2016, 81, 265. (d) Chen, B.; Guo, S.; Guo, X.; Zhang, G.; Yu, Y.
Org. Lett. 2015, 17, 4698. (e) Montevecchi, P. C.; Navacchia, M. L.;
Spagnolo, P. J. Org. Chem. 1997, 62, 5846.
AUTHOR INFORMATION
Corresponding Authors
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(15) Tang, S.; Liu, K.; Liu, C.; Lei, A. Chem. Soc. Rev. 2015, 44, 1070.
(16) Ono, N. The Nitro Group in Organic Synthesis; Wiley-VCH:
Weinheim, 2001.
ORCID
(17) For selected examples on the use of AgNO2 in nitration reactions,
see: (a) Pawar, G. G.; Brahmanandan, A.; Kapur, M. Org. Lett. 2016, 18,
448. (b) Yuan, B.; Zhang, F.; Li, Z.; Yang, S.; Yan, R. Org. Lett. 2016, 18,
5928. (c) Wu, D.; Zhang, J.; Cui, J.; Zhang, W.; Liu, Y. Chem. Commun.
2014, 50, 10857. (d) Xue, C.; Fu, C.; Ma, S. Chem. Commun. 2014, 50,
15333. (e) Maity, S.; Manna, S.; Rana, S.; Naveen, T.; Mallick, A.; Maiti,
D. J. Am. Chem. Soc. 2013, 135, 3355.
(18) (a) NaNO2: Zhao, A.; Jiang, Q.; Jia, J.; Xu, B.; Liu, Y.; Zhang, M.;
Liu, Q.; Luo, W.; Guo, C. Tetrahedron Lett. 2016, 57, 80. (b) AgNO3:
Zhang, L.; Liu, Z.; Li, H.; Fang, G.; Barry, B.-D.; Barry, T. A.; Bi, X.; Liu,
Q. Org. Lett. 2011, 13, 6536. (c) Fe(NO3)3·9H2O: Naveen, T.; Maity, S.;
Sharma, U.; Maiti, D. J. Org. Chem. 2013, 78, 5949. (d) Cu(NO3)2·
3H2O: Fan, Z.; Ni, J.; Zhang, A. J. Am. Chem. Soc. 2016, 138, 8470.
(e) Manna, S.; Maity, S.; Rana, S.; Agasti, S.; Maiti, D. Org. Lett. 2012, 14,
1736. (f) Dutta, U.; Lupton, D. W.; Maiti, D. Org. Lett. 2016, 18, 860.
(19) (a) Huang, H.; Zhang, G.; Chen, Y. Angew. Chem., Int. Ed. 2015,
54, 7872. (b) Tan, H.; Li, H.; Ji, W.; Wang, L. Angew. Chem., Int. Ed. 2015,
54, 8374.
(20) Tang, X.; Huang, L.; Xu, Y.; Yang, J.; Wu, W.; Jiang, H. Angew.
Chem., Int. Ed. 2014, 53, 4205.
(21) Sun, X.; Lyu, Y.; Zhang-Negrerie, D.; Du, Y.; Zhao, K. Org. Lett.
2013, 15, 6222.
(22) N-Brominated imines are rarely reported, see: Bohnen, C.; Bolm,
C. Org. Lett. 2015, 17, 3011.
(23) Zhu, Z.; Tang, X.; Li, J.; Li, X.; Wu, W.; Deng, G.; Jiang, H. Chem.
Commun. 2017, 53, 3228.
(24) Hartmann, M.; Li, Y.; Studer, A. J. Am. Chem. Soc. 2012, 134,
16516.
Author Contributions
∥Y.N. and X.-F.Z. contributed equally to this work.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
X.B. thanks NSFC (21522202, 21502017) and Y.W. thanks
NSFC (21273140) and the OIT program of Shanxi for support.
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REFERENCES
■
(1) Banert, K. In Organic Azides: Syntheses and Applications; Banert, S.,
Ed.; John Wiley & Sons Ltd: Chichester, 2010.
(2) Forster, M. O.; Newman, S. H. J. Chem. Soc., Trans. 1910, 97, 2570.
(3) (a) Hu, B.; DiMagno, S. G. Org. Biomol. Chem. 2015, 13, 3844.
(b) Ni, H.; Zhang, G.;Yu, Y. Curr. Org. Chem. 2015, 19, 776. (c) Chiba, S.
Synlett 2012, 23, 21. (d) Jung, N.; Brase, S. Angew. Chem., Int. Ed. 2012,
51, 12169.
(4) (a) Bates, R. Organic Synthesis Using Transition Metals, 2nd ed.; John
Wiley & Sons: Chichester, 2012. (b) Tsuji, J. Transition Metal Reagents
and CatalystsInnovations in Organic Synthesis; John Wiley and Sons:
Chichester, 2000.
(5) For the synthesis from alkenes, see: (a) Hassner, A.; Kropp, J. E.;
Kent, G. J. J. Org. Chem. 1969, 34, 2628 and references cited therein. For
the latest synthesis from alkynes, see: (b) Liu, Z.; Liu, J.; Zhang, L.; Liao,
P.; Song, J.; Bi, X. Angew. Chem., Int. Ed. 2014, 53, 5305. (c) Liu, Z.; Liao,
P.; Bi, X. Org. Lett. 2014, 16, 3668.
(6) (a) Lopez, E.; Lopez, L. Angew. Chem., Int. Ed. 2017, 56, 5121.
́
(b) Shu, W.; Lorente, A.; Gomez-Bengoa, E.; Nevado, C. Nat. Commun.
2017, 8, 13832. (c) Wang, Y.-F.; Toh, K. K.; Ng, E. P. J.; Chiba, S. J. Am.
Chem. Soc. 2011, 133, 6411. (d) Wang, Y.-F.; Chiba, S. J. Am. Chem. Soc.
2009, 131, 12570. (e) Wang, Y.-F.; Toh, K. K.; Lee, J.-Y.; Chiba, S.
Angew. Chem., Int. Ed. 2011, 50, 5927.
(7) (a) Qin, C.; Feng, P.; Ou, Y.; Shen, T.; Wang, T.; Jiao, N. Angew.
Chem., Int. Ed. 2013, 52, 7850. (b) Zhang, F.-L.; Wang, Y.-F.; Lonca, G.
H.; Zhu, X.; Chiba, S. Angew. Chem., Int. Ed. 2014, 53, 4390. (c) Zhang,
Z.; Kumar, R. K.; Li, G.; Wu, D.; Bi, X. Org. Lett. 2015, 17, 6190. (d) Lin,
C.; Shen, Y.; Huang, B.; Liu, Y.; Cui, S. J. Org. Chem. 2017, 82, 3950.
(8) (a) Wang, Y.-F.; Lonca, G. H.; Chiba, S. Angew. Chem., Int. Ed. 2014,
53, 1067. (b) Wu, S.-W.; Liu, F. Org. Lett. 2016, 18, 3642. (c) Qin, H.-T.;
Wu, S.-W.; Liu, J.-L.; Liu, F. Chem. Commun. 2017, 53, 1696. (d) Chen,
̈
(25) Gao, B.; Zhao, Y.; Hu, J. Angew. Chem., Int. Ed. 2015, 54, 638.
(26) For proposal on 1,3-H transfer in a reaction, see: (a) Ke, J.; Tang,
Y.; Yi, H.; Li, Y.; Cheng, Y.; Liu, C.; Lei, A. Angew. Chem., Int. Ed. 2015,
54, 6604. (b) Yang, H.-B.; Selander, N. Chem. - Eur. J. 2017, 23, 1779.
(c) Ran, L.; Ren, Z.-H.; Wang, Y.-Y.; Guan, Z.-H. Green Chem. 2014, 16,
112.
(27) For a mechanism proposal by a water-aided process, see:
(a) Liang, Y.; Zhou, H.; Yu, Z.-X. J. Am. Chem. Soc. 2009, 131, 17783.
(b) Shi, F.-Q.; Li, X.; X, Y.; Zhang, L.; Yu, Z.-X. J. Am. Chem. Soc. 2007,
129, 15503. (c) Xiao, P.; Yuan, H.; Liu, J.; Zheng, Y.; Bi, X.; Zhang, J. ACS
Catal. 2015, 5, 6177.
D
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