DOI: 10.1039/C4GC00005F
Page 5 of 6
COMMUNICATION
Green Chemistry
Journal Name
a College of Chemistry and Chemical Engineering, Chongqing University,
5b, 95%,
4- : 3- = 66 : 34
5a, 62%b
5c, 88%
b
Key Laboratory for Optoelectronic Technology and Systems of
Education Ministry of China, College of Optoelectronic Engineering,
Chongqing University, Chongqing 400044, China.
5d, 92%,
4- : 5- = 80 : 20
5f, 81%,
p- : o- : m- = 55 : 35 : 10
5e, 96%
† Electronic supplementary information (ESI) available: Experimental
procedures, characterisation data. See DOI: 10.1039/c000000x/
1
(a) H. H. Sun, V. J. Paul and W. Fenical, Phytochemistry, 1983, 22,
5h, 75%c,
1- : 2- = 74 : 26
45%d (1- : 2- = 76 :
24), 49%e
743; (b) M. G. Nordberg, K. Kolmodin, J. Aquist, S. F. Queener and
A. Hallberg, J. Med. Chem., 2001, 44, 2391.
2
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5g, 35%,
o- > 99%
5i, 50%,b
2- : 3- = 52 : 48
65%f (1- : 2- = 75 :
25), 26%e
22% g, 70% e
1- : 2- = 75 : 25
M. Li, J. C. Yang and Y. Q. Shi, Sensors and Actuators B, 2011, 156
,
553; (f) Y. Q. Shi, X. M. Li, J. C. Yang, F Gao and C. Y. Tao, J.
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3
4
5
(a) M. Mirza-Aghayan, R. Boukherroub, and M. Rahimifard,
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5k, 92%,
4- > 99%
5j, 96%
5l, 62%,
5o, 97%,
For recent reviews on transition-metal catalyzed direct benzylation,
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4- > 99%
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p- > 99%
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p- > 99%
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a Conditions: 1 (1.0 mmol), BF3-OEt2 (1.2 mmol), arene (2.0 mL), 120 C, in
air for 2 h; yields of isolated products after silica gel column chromatography
are given; isomer ratios of p- : o- : m- determined by 13C NMR. b The reaction
o
6
(a) A. Metzger, M. A. Schade and P. Knochel, Org. Lett., 2008, 10,
1107; (b) C. Duplais, A. Krasovskiy, A. Wattenberg and B. H.
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c
was carried out under reflux of the arene. BF3-OEt2 (1.2 mmol), arene (4.0
d
mmol), CHCl3 (2.0 mL).
Isolated yields under N2 atmosphere using
anhydrous arenes. Yields of isolated remaining starting materials. Isolated
yields under N2 atmosphere using anhydrous arenes with extra 1.2
equivalents of H2O. Isolated yields under N2 atmosphere using anhydrous
arenes with extra 2.4 equivalents of H2O.
e
f
7
8
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8
g
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Conclusions
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2009, 600.
In summary, BF3-H2O produced in-situ from BF3-OEt2 and
residual water was found to be an efficient acid to promote the
reaction of arenes with different benzyl ethers in good-to-excellent
yields. This environmentally friendly and highly efficient procedure
shows wide functional group compatibilities to provide a practical
synthetic method for the preparation of diarylmethanes with good
regioselectivities especially for secondary benzyl ethers.
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Acknowledgements
We are grateful for the financial support of the National Science
Foundation of China (No. 21372265 and No. 61271059), the
Scientific Research Fundings of the Scientific Research Foundation
for the Returned Overseas Chinese Scholars, the State Education
Ministry, the Natural Science Foundation Project of CQ CSTC (No.
cstc2013jcyjA0217), and the Fundamental Research Funds for the
Central Universities (No. CDJRC10220004, No. CDJZR11220005
and No. CQDXWL-2013-Z012).).
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8
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Notes and references
4 | J. Name., 2012, 00, 1-3
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