4654
Y.-H. Ye et al. / Tetrahedron 67 (2011) 4649e4654
3. Conclusion
Young Scientist. We also thank the Sichuan University Analytical &
Testing Center for NMR analysis.
In summary, we have demonstrated a novel benzylic CeH
amination strategy via dehydrogenative-coupling by using an in-
expensive catalyst/oxidant (CoBr2/tBuOOtBu) system. The reaction
could be applicable to various unmodified amides including pri-
mary or secondary sulfonamides, carboxamides, and carbamates.
Supplementary data
Detailed experimental procedures and compound character-
ization. Supplementary data associated with this article can be
4. Experimental
4.1. General
References and notes
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Ethylbenzene (1 mL), or
a solution of diphenylmethane
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amide (0.5 mmol), CoBr2 (0.1 mmol) and AcOH (0.05 mmol) at
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dried over MgSO4 and removed under reduced vacuum. The resi-
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acetate and hexane to afford the desired product.
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J¼7.2 Hz), 5.02 (d, 1H, J¼6.8 Hz), 2.38 (s, 3H). 13C NMR (100 MHz,
CDCl3)
d 143.2, 140.5, 137.4, 129.4, 128.5, 127.6, 127.4, 127.2, 61.3,
21.5. HRMS (ESI) calcd for C20H18NO2S (MꢁH)ꢁ 336.1056; found
336.1045.
Compound 5a: 96%; white solid; 1H NMR (400 MHz, CDCl3)
d
7.82 (t, 2H, J¼7.2 Hz), 7.26e7.53 (m, 13H), 6.69 (d, br, 1H, J¼7.2 Hz),
6.46 (d, 1H, J¼8.0 Hz). 13C NMR (150 MHz, CDCl3)
d 166.5, 141.5,
134.2, 131.7, 128.8, 128.6, 127.6, 127.5, 127.1, 57.5. HRMS (ESI) calcd
for C20H17NONa (MþNa)þ 310.1208; found 310.1220.
Acknowledgements
This work was financially supported by the National Science
Foundation of China (Nos. 20725206, 20732004, and 21021001),
Program for Changjiang Scholars and Innovative Research Team in
University, the Key Project of Chinese Ministry of Education in
China and Scientific Fund of Sichuan Province for Outstanding
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