Yusuke Izawa and Shannon S. Stahl
COMMUNICATIONS
Experimental Section
B 1997, 115, 241–246; h) M. Okamoto, T. Yamaji,
Chem. Lett. 2001, 212–213.
[
2] a) D. R. Stuart, K. Fagnou, Science 2007, 316, 1172–
Representative Procedure for Aerobic Oxidative
Coupling of o-Xylene
1
175; b) D. R. Stuart, E. Villemure, K. Fagnou, J. Am.
Chem. Soc. 2007, 129, 12072–12073; c) B.-J. Li, S.-L.
Tian, Z. Fang, Z.-J. Shi, Angew. Chem. 2008, 120, 1131–
1134; Angew. Chem. Int. Ed. 2008, 47, 1115–1118;
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2008, 130, 9254–9256; i) P. Xi, F. Yang, S. Qin, D.
Zhao, J. Lan, G. Gao, C. Hu, J. You, J. Am. Chem. Soc.
Method A: In a disposable culture tube, palladium com-
plexes (0.094 mmol), 2-fluoropyridine (0.19 mmol), trifluoro-
acetic acid (0.113 mmol), o-xylene (0.4 g) and propylene car-
bonate (0.4 g) were combined. The reaction tubes were
placed in a 48-well aluminum block mounted on a large ca-
pacity mixer (Glas-Col) that enabled several reactions to be
performed simultaneously under
a
constant pressure
(
approx. 1 atm) with controlled temperature and orbital agi-
tation. The headspace above the tubes was purged with
oxygen gas for ca. 5 min. The reactions were vortexed for 17
h under 1 atm of O . After the reactions were stopped, n-
2
hexadecane was added to the reaction mixture as an internal
standard. Samples were evaluated by GC for the products
and remaining starting materials.
2
010, 132, 1882–1884.
3] R. van Helden, G. Verberg, Recl. Trav. Chim. Pays-Bas
965, 84, 1263–1273.
[
[
Method B: In
a 6-mL vial, palladium complexes
1
(
0.02 mmol), 2-fluoropyridine (0.04 mmol), trifluoroacetic
4] a) J. M. Davidson, C. Triggs, Chem. Ind. 1966, 457;
b) J. M. Davidson, C. Triggs, Chem. Ind. 1967, 1361;
c) J. M. Davidson, C. Triggs, J. Chem. Soc. (A) 1968,
acid (0.024 mmol) and acetic acid (2 g) were combined and
stirred at room temperature for 30 min. The mixture was
used as a stock solution. In a disposable culture tube,
copper triflate (0.04 mmol) and o-xylene (0.4 g) were com-
bined. Then, the stock solution (0.4 g) was added. Reaction
tubes were placed in a 48-well parallel reaction mounted on
a large capacity mixer (Glas-Col) that enabled several reac-
tions to be performed simultaneously under a constant pres-
sure (approx. 1 atm) with controlled temperature and orbital
agitation. The headspace above the tubes was purged with
oxygen gas for ca. 5 min. The reactions were vortexed for 17
1
324–1330.
[
[
5] This process is currently used by Ube industries Ltd.
For representative pantents, see: a) H. Itatani, M. Ka-
shima, T. M. Matsuda, H. Yoshimoto, H. Yamamoto,
U.S. Patent 3,940,426, 1976; b) H. Itatani, H. Yoshimo-
to, A. Shiotani, A. Yokota, M, Yoshikiyo, U.S. Patent
4
,294,976, 1981; c) H. Itatani, A. Shiotani, A. Yokota,
Japanese Patent 33379, 1985.
6] An efficient catalyst for dimethyl o-phthalate was re-
h under 1 atm of O . After the reactions were stopped, n-
2
ported. See: a) H. Iataaki, H. Yoshimoto, J. Org. Chem.
hexadecane was added to the reaction mixture as an internal
standard. Samples were evaluated by GC for the products
and remaining starting materials.
1
973, 38, 76–79; b) H. Yoshimoto, H. Itatani, Bull.
Chem. Soc. Jpn. 1973, 46, 2490–2492; c) H. Yoshimoto,
H. Itatani, J. Catal. 1973, 31, 8–12; d) A. Shiotani, M.
Yoshikiyo, H. Itatani, J. Mol. Catal. 1983, 18, 23–31; e)
A, Shiotani, H, Itatani, T. Inagaki, J. Mol. Catal.
1
986, 34, 57–66.
Acknowledgements
[7] a) Y. Mohri, Seni Gakkaishi 1994, 50, 96–101; b) J. A.
Kreuz, J. R. Edman, Adv. Mater. 1998, 10, 1229.
[8] A NineSigmaꢃ proposal request (#11222–1) was
issued in Oct. 2008, entitled “Benzene Ring Catalytic
Coupling Technology”, in which a multi-billion dollar
chemical manufacturer targeted the development of
novel catalysts for the direct coupling of substituted ar-
omatics.
We thank Dr. I. A. Guzei and L. C. Spencer for X-ray crys-
tallographic assistance. We are grateful for financial support
from Mitsubishi Chemical Corporation (YI) and the NIH
(
R01 GM67163).
[
9] Aerobic oxidation of bixylyl to biphthalate has been
accomplished under conditions similar to the well-es-
tablished industrial processes for benzylic oxidation,
such as the Mid-Century process for commercial pro-
duction of terephthalic acid from p-xylene: T. Kumano,
A. Ogoshi, Japanese Patent 34227, 2003.
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Adv. Synth. Catal. 2010, 352, 3223 – 3229