ORGANIC
LETTERS
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Vol. XX, No. XX
Palladium-Catalyzed Cascade Oxidation/
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000–000
sp CÀH Acylation of Azoarenes with Aryl
Methanes
†
,§
‡,§
‡
,‡
Feng Xiong, Cheng Qian, Dongen Lin, Wei Zeng,* and Xiaoxia Lu*
,†
Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China,
and School of Chemistry and Chemical Engineering, South China University of
Technology, Guangzhou 510641, China
luxx@cib.ac.cn; zengwei@scut.edu.cn
Received September 4, 2013
ABSTRACT
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A Pd-catalyzed cascade oxidation/sp CÀH bond acylation of azoarenes was developed in which readily available aryl methanes were used as the
in situ generated acyl sources. This reaction provides a convenient access to ortho-acyl azoarenes under mild conditions.
2
The regio- and chemoselective CÀH bond activation of
organic molecules by transition metal catalysts provides
an atom-economic access to the construction of carbonÀ
carbon or carbonÀheteroatom bonds, which could further
lead to simple and efficient synthetic strategies for the
by Ryabov, most elegant work has demonstrated that
cyclometalated intermediates which have derived from
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substrates containing a nitrile, ketone, carboxylic
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5
6
7
8
9
acid, alcohol, triazoene, pyridine, ester, amide,
4b,10
9a,11
aldehyde,
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imine, or oxazoline directing group, etc.,
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functionalization of organic compounds. Since the dis-
covery of directed ortho metalation of organic compounds
could be easily trapped by appropriated electrophiles or
nucleophiles and realized a versatile CÀH functionalization.
However, although significant attention has been recently
focused on the above-mentioned directing groups, there
are rare reported cases using the azo group as a directing
group to accelerate the CÀH activation/functionalization
†
Chengdu Institute of Biology.
South China University of Technology.
These authors contributed equally.
‡
§
(
1) For selected reviews on transition-metal-catalyzed CÀH activa-
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tion: (a) Bellina, F.; Rossi, R. Chem. Rev. 2010, 110, 1082. (b) Song, G.;
Wang, F.; Li, X. Chem. Soc. Rev. 2012, 41, 3651.
process.
(
(
(
2) Ryabov, A. D. Synthesis 1985, 233.
3) Mikami, K.; Hatano, M.; Terada, M. Chem. Lett. 1999, 55.
4) Selected examples: (a) Padala, K.; Jeganmohan, M. Org. Lett.
(9) Selected examples: (a) Park, S. H.; Kim, J. Y.; Chang, S. Org. Lett.
2011, 13, 2372. (b) Besset, T.; Kuhl, N.; Patureau, F. W.; Glorius, F.
Chem.;Eur. J. 2011, 17, 7167.
2
011, 13, 6144. (b) Patureau, F. W.; Besset, T.; Glorius, F. Angew.
Chem., Int. Ed. 2011, 50, 1064.
5) Selected examples: (a) Shi, B. F.; Zhang, Y. H.; Lam, J. K.; Wang,
(10) Selected examples: (a) Boele, M. D. K.; Strijdonck, G. P. F.;
Vries, A. H. M.; Kamer, P. C. J.; Vries, J. G.; Leeuwen, P. W. N. M.
J. Am. Chem. Soc. 2002, 124, 1586. (b) Wasa, M.; Engle, K. M.; Yu, J. Q.
J. Am. Chem. Soc. 2010, 132, 3680. (c) Dai, H. X.; Stepan, A. F.;
Plummer, M. S.; Zhang, Y. H.; Yu, J. Q. J. Am. Chem. Soc. 2011, 133,
7222. (d) Li, C.; Wang, L.; Li, P.; Zhou, P. Chem.;Eur. J. 2011, 17, 10208.
(11) Selected examples: (a) Kakiuchi, F.; Sato, F.; Igi, K.; Chatani,
N.; Murai, S. Chem. Lett. 2001, 30, 386. (b) Gurbuz, N.; Ozdemir, I.;
Cetinkaya, B. Tetrahedron Lett. 2005, 46, 2273.
(
D. H.; Yu, J. Q. J. Am. Chem. Soc. 2010, 132, 460. (b) Wang, D. H.;
Engle, K. M.; Shi, B. F.; Yu, J. Q. Science 2010, 327, 315.
(
J. Q. J. Am. Chem. Soc. 2010, 132, 5916. (b) Huang, C.; Chattopadhyay,
B.; Gevorgyan, V. J. Am. Chem. Soc. 2011, 133, 12406. (c) Mewald, M.;
Schiffner, J. A.; Oestreich, M. Angew. Chem., Int. Ed. 2012, 51, 1763.
6) Selected examples: (a) Lu, Y.; Wang, D. H.; Engle, K. M.; Yu,
(
7) Wang, C.; Chen, H.; Wang, Z.; Chen, J.; Huang, Y. Angew.
Chem., Int. Ed. 2012, 51, 7242.
8) Selected examples: (a) Garcia-Rubia, A.; Fernandez-Ibanez,
M. A.; Arrayas, R. G.; Carretero, J. C. Chem.;Eur. J. 2011, 17, 3567.
b) Garcia-Rubia, A.; Urone, B.; Arrays, R. G.; Carretero, J. C. Angew.
Chem., Int. Ed. 2011, 50, 10927. (c) Kim, J.; Chang, S. J. Am. Chem. Soc.
010, 132, 10272. (d) Li, Y.; Li, B. J.; Wang, W. H.; Huang, W. P.;
Zhang, X. S.; Cheng, K.; Shi, Z. J. Angew. Chem., Int. Ed. 2011, 50, 2115.
(12) Selected examples: (a) Jayakumar, J.; Parthasarthy, K.; Cheng,
C. H. Angew. Chem., Int. Ed. 2012, 51, 197. (b) Li, L.; Brennessel, W. W.;
Jones, W. D. J. Am. Chem. Soc. 2008, 130, 12414.
(
(
(13) Selected examples: (a) Chen, X.; Li, J. J.; Hao, X. S.; Goodhue,
C. E.; Yu, J. Q. J. Am. Chem. Soc. 2006, 128, 78. (b) Moore, E. J.; Pretzer,
W. R.; O Connell, T. J.; Harris, J.; LaBounty, L.; Chou, L.; Grimmer,
’
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S. S. J. Am. Chem. Soc. 1992, 114, 5888.
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0.1021/ol402537t r XXXX American Chemical Society