A highly active heterogeneous palladium catalyst for the Suzuki-Miyaura and Ullmann coupling reactions of aryl chlorides in aqueous media

Article abstract of DOI:10.1002/anie.201000576

(Figure Presented) A heterogeneous palladium catalyst, which is supported on a metal - organic framework, MIL-101, is highly efficient in water-mediated coupling reactions of chloroarenes. High yields are obtained in Suzuki-Miyaura cross-coupling and Ullmann homocoupling reactions of substituted aryl chlorides. Furthermore, the catalyst is easily recoverable and reusable (see picture; Cr blue, O red, C white).

Full text of DOI:10.1002/anie.201000576

Communications
DOI: 10.1002/anie.201000576
Coupling Reactions
A Highly Active Heterogeneous Palladium Catalyst for the Suzuki–
Miyaura and Ullmann Coupling Reactions of Aryl Chlorides in
Aqueous Media**
Bizhen Yuan, Yingyi Pan, Yingwei Li,* Biaolin Yin, and Huanfeng Jiang*
À
Palladium-catalyzed carbon-carbon (C C) coupling reactions
of aryl halides, such as Suzuki–Miyaura and Ullmann
reactions, are very important as versatile routes to construct-
ing biaryl units in organic synthesis.[1] Although homogeneous
palladium catalysts has been extensively investigated, indus-
trial applications of these reactions remain challenging
because the catalysts are expensive, cannot be recycled, and
are difficult to separate from the product mixture,[1,2] which is
a particular drawback for applications in the pharmaceutical
industry; heterogeneous palladium catalysts are a promising
solution to these problems. A number of solid materials,[3]
such as carbon structures,[4] polymers,[5] and mesoporous
silica[6] have been employed as supports for palladium.
Numerous heterogeneous palladium catalysts have been
utilized in the coupling reactions of aryl bromides or
iodides;[1b] nevertheless, only a very limited number of such
palladium catalysts have been reported for coupling reactions
with aryl chlorides.[7] From a practical point of view, the use of
aryl chlorides is desirable because they are inexpensive and
readily available.[1] However, the activation of aryl chlorides
is much more difficult than aryl bromides or iodides.
Furthermore, the reported coupling reactions were mostly
carried out in organic solvents. From a sustainable chemistry
viewpoint, the use of water instead of volatile organic solvents
is particularly important. Therefore, the development of
heterogeneous catalysts that can activate aryl chlorides and
facilitate the coupling reactions of aryl chlorides in aqueous
media is highly desirable.[1]
reports on MOFs as catalysts and even fewer reports on
supporting noble metal nanoparticles (NPs) on MOFs as
catalysts for heterogeneous catalysis.[10] A palladium-contain-
ing MOF (Pd-MOF) has been reported to be an active
catalyst for the Suzuki–Miyaura coupling reaction of aryl
bromides.[11] To the best of our knowledge, there are currently
no reports of employing MOFs as supports for metal NPs in
Suzuki–Miyaura and Ullmann coupling reactions of aryl
chlorides.
Herein, we report the water-mediated coupling reactions
of aryl chlorides over a heterogeneous palladium catalyst,
which is deposited on a zeolite-type MOF. This work
represents the first example of an active catalyst, comprised
of a MOF as a support for metal NPs, for the coupling
reactions of aryl chlorides. We have chosen MIL-101 (Cr3-
(F,OH)(H2O)2O[(O2C)-C6H4-(CO2)]3·nH2O
(n ꢀ 25))
because it has a large surface area (BET, ca. 4000 m2 gÀ1),[12]
which is desirable for depositing small palladium NPs.
Furthermore, the hybrid pore surface, which constitutes
both hydrophilic and hydrophobic networks,[13] and the large
pore size (ca. 30 ꢀ) may facilitate the selective adsorption of
an aryl substrate in water and mass transfer inside the pores.
Moreover, MIL-101 is stable when exposed to indoor ambient
air and treated with various organic solvents.[12,14]
MIL-101 was synthesized and purified according to the
reported procedure.[12] Supported palladium NPs were pre-
pared by impregnation of activated MIL-101 with a Pd(NO3)2
precursor that was diluted in N,N-dimethylformamide (for
experimental details, see the Supporting Information). The
palladium loading (ca. 1 wt%) did not result in any apparent
loss of crystallinity in the X-ray diffraction patterns (see the
Supporting Information), indicating that the integrity of the
MIL-101 framework was maintained. The TEM image, shown
in Figure 1, shows that the palladium NPs were highly
Metal-organic frameworks (MOFs) have emerged as a
particular class of functional materials owing to their high
surface area, porosity, and chemical tunability.[8] Because of
these properties, MOFs have promising applications in
heterogeneous catalysis. However, over the past decade,
most of the research efforts have been focused on preparing
new MOFs and studying their applications in gas storage and
separation.[9] So far, there are a relatively limited number of
[*] B. Z. Yuan, Y. Y. Pan, Prof. Y. W. Li, Dr. B. L. Yin, Prof. H. F. Jiang
School of Chemistry and Chemical Engineering
South China University of Technology
Guangzhou 510640 (China)
Fax: (+86)20-2223-6337
E-mail: liyw@scut.edu.cn
jianghf@scut.edu.cn
[**] This work was supported by the NSF of China (20803024, 20936001,
and 20625205), and the program for New Century Excellent Talents
in Universities (NCET-08-0203).
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/anie.201000576.
Figure 1. TEM images of Pd/MIL-101 before the reaction (left) and
after five cycles (right).
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Chemie
dispersed, with a mean diameter of (1.9 Æ 0.7) nm, as esti-
mated by size distribution (see the Supporting Information).
The slight decreases in the amount of N2 adsorption and pore
size indicate that the cavities of MIL-101 could be occupied
by highly dispersed palladium NPs and/or blocked by
palladium NPs that were located at the surface (see the
Supporting Information), as in the case of metal NPs loaded
onto MOF-5, ZIF-8, and zeolitic materials.[10d,15] The XPS
investigation of Pd/MIL-101 at the palladium 3d level indi-
cated that most of the palladium was in the reduced form (see
the Supporting Information).
of TBAB when NaOMe was used as base (Table 1, entries 11
and 12). Complete conversion into the desired product is
expected with a prolonged reaction time. The much higher
yield achieved with NaOMe (Table 1, entry 9) as compared
with NaOH (Table 1, entry 7) may be due to the presence of a
small amount of methanol that is formed from the reaction of
NaOMe with water; the combination of NaOH with methanol
was also efficient in the Suzuki–Miyaura coupling reaction
(Table 1, entry 13).
To investigate the scope of aryl chlorides that could be
tolerated in the Suzuki–Miyaura coupling reaction with
phenylboronic acid, different aryl chlorides were employed
in the reaction (Table 2). High catalytic activities were
À
It is well known that activation of C Cl bond is much
À
À
more difficult than C Br and C I bonds, and in general
requires harsher reaction conditions in heterogeneous catal-
ysis system.[1] Herein, 4-chloroanisole, a deactivated aryl
chloride, was employed as the substrate in the screening of
Suzuki–Miyaura coupling reaction parameters over Pd/MIL-
101. The reaction was first tested on the Suzuki–Miyaura
coupling reaction of 4-chloroanisole with phenylboronic acid
using K2CO3 as base in neat water at 808C. Only trace
amounts of cross-coupling product were formed in 6 hours
(Table 1, entry 1). The addition of tetrabutylammonium
Table 2: Suzuki–Miyaura coupling reactions of aryl chlorides over
supported palladium catalysts.[a]
Entry
Aryl chloride
Product
Yield [%][b]
97 (99)
1
2
3
96 (99)
Table 1: Suzuki–Miyaura coupling of 4-chloroanisol with Pd/MIL-101.[a]
96 (99)
4
81 (83)
Entry
Base
TBAB [mmol][b]
t [h]
Yield [%][c]
5
95 (98)
<3
1
2
3
4
5
6
7
8
9
10
11
12
13[d]
K2CO3
K2CO3
K3PO4
0
6
6
6
6
6
6
6
6
6
6
6
20
6
<3
43
<3
23
21
<3
11
17
65
82
43
78
63
6[c]
7[d]
8[e]
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.3
0
35 (39)
16 (21)
KF
Cs2CO3
Na2CO3
NaOH
Et3N
NaOMe
NaOMe
NaOMe
NaOMe
NaOH
[a] Reaction conditions: aryl chloride (0.5 mmol), phenylboronic acid
(0.75 mmol), NaOMe (1.5 mmol), TBAB (0.3 mmol), water (4 mL), and
Pd/MIL-101 (0.9 mol% Pd), 808C, 20 hours, under N2. [b] Yield of
isolated product (GC yield in parenthesis). [c] PdII/MIL-101 (0.9 mol%
Pd). [d] Pd/C (0.9 mol% Pd). [e] Pd/ZIF-8 (0.9 mol% Pd).
0
0.1
[a] Reaction conditions: 4-chloroanisol (0.5 mmol), phenylboronic acid
(0.75 mmol), base (1.5 mmol), water (4 mL), and Pd/MIL-101
(0.9 mol% Pd), 808C, under N2. [b] Tetrabutylammonium bromide.
[c] Determined by GC analysis against an internal standard. [d] Methanol
(1.5 mmol) was added.
observed for chlorobenzene and both electron-rich and
electron-poor aryl chlorides, affording the corresponding
biphenyl compounds in excellent yields in 20 hours under
the optimized reaction conditions (Table 2, entries 1–3). It
should be noted that 2-chloroanisol, which is both deactivated
and sterically hindered, could also be coupled in good yield in
20 hours (Table 2, entry 4). More-reactive aryl bromides were
also smoothly coupled to give their corresponding products
(Table 2, entry 5). However, the unreduced PdII/MIL-101
bromide (TBAB) enhanced the yield significantly (Table 1,
entry 2), presumably owing to the stabilization effect of the
palladium NPs.[7a,b,16] To determine the optimal experimental
conditions, the impact of various bases on the efficiency of
this process was studied because the nature of the base is
known to be crucial in this type of coupling reaction (Table 1,
entries 3–9). The highest yield was obtained when the
reaction was carried out using NaOMe as a base (Table 1,
entry 9). With NaOMe, a further increase in the amount of
TBAB significantly enhanced the conversion of 4-chloroani-
sol, giving a good yield (82%) of the cross-coupling product in
6 hours (Table 1, entry 10). It is noteworthy that the catalyst
could activate 4-chloroanisol effectively, even in the absence
À
afforded essentially no C C bond formation (Table 2,
entry 6), indicating that palladium in the reduced form is
the active site for the Suzuki–Miyaura coupling reaction. XPS
analysis of the PdII/MIL-101 catalyst after the reaction
revealed that the reduction of PdII to Pd0 was not significant
under the reaction conditions (see the Supporting Informa-
tion).
For comparison, a commercial Pd/C catalyst (1 wt%
palladium) was tested under the same reaction conditions
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Table 3: Ullmann coupling reactions of aryl chlorides over supported
(Table 2, entry 7); only 35% yield of cross-coupled product
palladium catalysts.[a]
was obtained using Pd/C in the coupling of 4-chloroanisol
with phenylboronic acid. In some reports, Pd/C has been
found to work efficiently for the coupling reaction of 4-
chloroanisol in aqueous media at 1408C.[7a,b] The much-lower
activity obtained in this study is probably due to the lower
reaction temperature than that used previously. Furthermore,
the different palladium source could be another cause for the
diverse activities.[7b] Low activity was also observed for
palladium-supported ZIF-8 (Zn(MeIM)2, MeIM = 2-methyl-
imidazole),[9a] one of representative MOFs with a surface area
of 1398 m2 gÀ1 and pore size of 11 ꢀ (Table 2, entry 8). The
much higher activity of Pd/MIL-101, as compared to Pd/ZIF-
8, may be attributed to the larger surface area and pore size of
MIL-101, which ensured the high dispersion of palladium
active sites and facilitated the diffusion of reactants and large
product molecules in the pores. Moreover, the enhanced
surface Lewis acidity on MIL-101 owing to the open metal
(Cr3+) sites[10b,g] would favor the adsorption of the chloroaryl
molecules, and thus enhance the activity. As previously
reported, the Al3+ ions that were incorporated into MCM-
41 may serve as Lewis-type acidic sites that may adsorb
iodoaryl molecules easily by the donation of the para elec-
trons in the benzene ring.[17]
The atmosphere in which the reaction was performed had
a significant impact on the efficiency of the Suzuki–Miyaura
coupling process. Performing the coupling of 4-chloroanisole
with phenylboronic acid reaction in open air resulted in a
much lower yield of cross-coupling product (ca. 33%) than
when the reaction was performed under a nitrogen atmos-
phere (ca. 96%, see Table 2, entry 2). This may be due to the
oxidation and homocoupling of phenylboronic acid by
molecular oxygen[18] that was dissolved in water over Pd/
MIL-101, because some phenol and biphenyl side-products
were formed in the reaction. Most interestingly, we detected
large amounts (ca. 66% selectivity) of 4,4’-dimethoxy
biphenyl, which might be formed from the homocoupling of
4-chloroanisol. These results indicate that a low ratio of
phenylboronic acid to 4-chloroanisol in the reactant mixture
favored the homocoupling process in a competition between
the homo- and cross-coupling reactions of 4-chloroanisol.
This was confirmed by comparing the results obtained with
different ratios of phenylboronic acid to 4-chloroanisol (see
the Supporting Information).
Entry
Aryl chloride
Product
Yield [%][b]
1[c]
2
97 (99)
96 (98)
<3
3[d]
4
96 (98)
96 (99)
95 (97)
5
6
[a] Reaction conditions: Aryl chloride (1.0 mmol), NaOMe (1.5 mmol),
TBAB (0.3 mmol), water (4 mL), Pd/MIL-101 (0.5 mol% Pd), 808C,
20 hours, under air. [b] Yield of isolated product (GC yield in paren-
thesis). [c] The reaction was carried out under a N2 atmosphere. [d] PdII/
MIL-101 (0.5 mol% Pd) was used.
conditions (Table 3, entry 3). These results indicate that
palladium in its reduced form is the active site for the
Ullmann coupling reaction, and the oxidation of metallic
palladium was not significant during the reaction in air.
Various aryl chlorides, such as chlorobenzene, 4-chloro-
phenol, and 4-chlorotoluene were also examined as substrates
for the Ullmann coupling reaction in air (Table 3, entries 4–6).
The conversion was essentially quantitative, with 100%
selectivity to the corresponding biphenyl compound at 808C
for all three substrates. It should be mentioned that the
symmetrical biaryl compounds are important intermediates
for synthesizing agrochemicals, pharmaceuticals, and natural
products. Wan et al. recently reported a highly active hetero-
geneous palladium/silica-carbon catalyst for the Ullmann
coupling of chlorobenzene that afforded 100% conversion
into the biphenyl product with moderate selectivity (64%) in
water and air at 1008C.[20] Our Pd/MIL-101 catalyst gave
exceptionally high activity and selectivity for the Ullmann
coupling of aryl chlorides using water as the solvent at a
moderate temperature (808C), thus showing great potential
for practical applications.
The Pd/MIL-101 catalyst can be easily recovered and
reused in the Ullmann coupling of 4-chloroanisol five times
without any loss of efficiency (see the Supporting Informa-
tion). The crystalline structure of the catalyst was mostly
retained after five catalytic cycles (see the Supporting
Encouraged by these interesting results, we examined the
catalytic activity of Pd/MIL-101 for the Ullmann homocou-
pling reaction of 4-chloroanisol in the absence of phenyl-
boronic acid under similar reaction conditions to those used
for the Suzuki coupling reactions. 4-Chloroanisol was coupled
to 4,4’-dimethoxy biphenyl in quantitative yield under a
nitrogen atmosphere (Table 3, entry 1). In the reaction
system, the reducing agent for the regeneration of Pd0 could
be the methanol produced from the reaction of NaOMe with
water. As demonstrated by a number of reports, alcohols
(such as ethanol or isopropanol) can be used as reducing
agents for Ullmann homocoupling.[19] It should be noted that
an excellent yield of 96% was achieved even when the
reaction was carried out in air (Table 3, entry 2); however, the
unreduced PdII/MIL-101 catalyst was ineffective under these
Information).
A TEM image of the reused catalyst
(Figure 1) indicates that the mean diameter of the nano-
particles is (2.0 Æ 0.6) nm (see the Supporting Information),
which is very similar to that before reaction. This result
indicates that no sintering of palladium NPs occurred during
the reaction. The liquid phase of the reaction mixture was
collected by hot filtration after the reaction and analyzed by
atomic absorption spectroscopy (AAS). Avery low amount of
dissolved palladium (less than 0.2% of the total palladium)
was detected in the solution at the end of the reaction.
Moreover, the catalyst was removed from the solution after
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approximately 50% conversion at the reaction temperature.
The isolated solution did not exhibit any further reactivity
under similar reaction conditions. These studies indicate that
the loss of palladium active sites is negligible, which could
account for the preservation of catalytic activity.
[1] a) N. Miyaura, A. Suzuki, Chem. Rev. 1995, 95, 2457; b) L. Yin, J.
Liebscher, Chem. Rev. 2007, 107, 133; c) A. F. Littke, G. C. Fu,
Angew. Chem. 2002, 114, 4350; Angew. Chem. Int. Ed. 2002, 41,
4176; d) R. Martin, S. L. Buchwald, Acc. Chem. Res. 2008, 41,
1461.
In conclusion, we have developed a highly efficient
heterogeneous catalyst system for the water-mediated
Suzuki–Miyaura and Ullmann coupling reactions of aryl
chlorides using porous MOF-supported palladium NPs as the
catalyst. Furthermore, the catalyst is stable, shows negligible
metal leaching, and maintains high catalytic activities over a
number of cycles. The use of MOFs as catalyst supports might
bring new opportunities in the development of highly active
[2] a) A. K. Diallo, C. Ornelas, L. Salmon, J. R. Aranzaes, D. Astruc,
Angew. Chem. 2007, 119, 8798; Angew. Chem. Int. Ed. 2007, 46,
8644; b) G. Altenhoff, R. Goddard, C. W. Lehmann, F. Glorius,
Angew. Chem. 2003, 115, 3818; Angew. Chem. Int. Ed. 2003, 42,
3690; c) W. A. Herrmann, K. ꢂfele, S. K. Schneider, E. Herdt-
weck, S. D. Hoffmann, Angew. Chem. 2006, 118, 3943; Angew.
Chem. Int. Ed. 2006, 45, 3859; d) T. Fujihara, S. Yoshida, H.
Ohta, Y. Tsuji, Angew. Chem. 2008, 120, 8434; Angew. Chem. Int.
Ed. 2008, 47, 8310; e) D. J. M. Snelders, G. van Koten, R. J. M.
Klein Gebbink, J. Am. Chem. Soc. 2009, 131, 11407; f) E.
Bustelo, C. Guꢃrot, A. Hercouet, B. Carboni, L. Toupet, P. H.
Dixneuf, J. Am. Chem. Soc. 2005, 127, 11582.
[3] L. Djakovitch, K. Kꢄhler, J. G. De Vries in Nanoparticles and
Catalysis (Ed.: D. Astruc), Wiley-VCH, Weinheim, 2008, p. 303.
[4] a) T. Tagata, M. Nishida, J. Org. Chem. 2003, 68, 9412; b) O.
Kitamura, S. Sako, T. Udzu, A. Tsutsui, T. Maegawa, Y.
Monguchi, H. Sajiki, Chem. Commun. 2007, 5069; c) T. Itoha,
H. Danjob, W. Sasakia, K. Uritaa, E. Bekyarovac, M. Araia, T.
Imamotoa, M. Yudasakad, S. Iijimad, H. Kanoha, K. Kanekoa,
Carbon 2008, 46, 172.
[5] a) D. H. Lee, J. H. Kim, B. H. Jun, H. Kang, J. Park, Y. S. Lee,
Org. Lett. 2008, 10, 1609; b) S. Schweizer, J.-M. Becht, C. L.
Drian, Org. Lett. 2007, 9, 3777; c) Y. Li, X. M. Hong, D. M.
Collard, M. A. El-Sayed, Org. Lett. 2000, 2, 2385; d) C. Ornelas,
A. K. Diallo, J. Ruiz, D. Astruc, Adv. Synth. Catal. 2009, 351,
2147.
[6] a) C. M. Crudden, M. Sateesh, R. Lewis, J. Am. Chem. Soc. 2005,
127, 10045; b) M. Choi, D.-H. Lee, K. Na, B.-W. Yu, R. Ryoo,
Angew. Chem. 2009, 121, 3727; Angew. Chem. Int. Ed. 2009, 48,
3673; c) S. MacQuarrie, B. Nohair, J. H. Horton, S. Kaliaguine,
C. M. Crudden, J. Phys. Chem. C 2010, 114, 57.
À
heterogeneous palladium catalysts for C C coupling or other
palladium-catalyzed reactions. Studies aimed at extending the
scope of Pd/MIL-101 to other organic transformations are
currently underway in our laboratories.
Experimental Section
MIL-101 was prepared from the hydrothermal reaction of Cr-
(NO3)3·9H2O, terephthalic acid, HF, and water at 2208C for 8 hours.
The powder was purified by post-reaction hydrothermal treatment
using hot ethanol (see the Supporting Information). Supported
palladium was prepared by impregnation of activated MIL-101 with
the desired amount of Pd(NO3)2 diluted in N,N-dimethylformamide
at room temperature. The impregnated MIL-101 sample was washed
with N,N-dimethylformamide and slowly dried in air. The as-
synthesized sample was further dried at 1508C for 8 hours, followed
by placing under a stream of H2 at 2008C for 2 hours to yield Pd/MIL-
101. The palladium loading on the sample was 0.99 wt%, based on
atomic absorption spectroscopy (AAS) analysis. Detailed methods
for preparation and characterization are described in the Supporting
Information.
Typical procedure for Suzuki–Miyaura coupling reaction: Aryl
halide (0.5 mmol), phenylboronic acid (0.75 mmol), NaOMe
(1.5 mmol), TBAB (0.3 mmol), and palladium catalyst (0.9 mol%)
were added to 4 mL deionized water. The reaction mixture was stirred
at the desired temperature under a N2 atmosphere. The solution was
filtered and washed with brine and diethyl ether. The organic phase
was subsequently extracted with diethyl ether (3 ꢁ 20 mL), dried over
MgSO4, and concentrated in vacuo. The crude product was quantified
by GC-MS analysis. The product was purified by chromatography on
silica gel and characterized by GC-MS and 1H NMR spectroscopy.
Typical procedure for the Ullmann coupling reaction: Aryl halide
(1.0 mmol), NaOMe (1.5 mmol), and TBAB (0.3 mmol) were mixed
in deionized water (4 mL) before the palladium catalyst (0.5 mol%)
was added to the reaction vessel. The reaction mixture was stirred at
808C under air. To test the recyclability of the catalyst, the Ullmann
coupling reactions were performed with 4-chloroanisol, using the
same reaction conditions as described above, except using the
recovered catalyst each time. The catalyst was isolated from the
reaction solution at the end of each cycle, washed with water and
toluene, and then dried under vacuum at 1508C. The dried catalyst
was then reused in a subsequent run. Detailed methods for catalytic
measurements and analysis are described in the Supporting Informa-
tion.
[7] For heterogeneous palladium-catalyzed coupling reactions of
aryl chlorides, see: a) M. Lysꢃn, K. Kꢄhler, Synlett 2005, 1671;
b) M. Lysꢃn, K. Kꢄhler, Synthesis 2006, 692; c) M.-J. Jin, D.-H.
Lee, Angew. Chem. 2010, 122, 1137; Angew. Chem. Int. Ed. 2010,
49, 1119; d) B. M. Choudary, S. Madhi, N. S. Chowdari, M. L.
Kantam, B. Sreedhar, J. Am. Chem. Soc. 2002, 124, 14127; e) Y.
Tsuji, T. Fujihara, Inorg. Chem. 2007, 46, 1895.
[8] a) J. R. Long, O. M. Yaghi, Chem. Soc. Rev. 2009, 38, 1213; b) S.
Kitagawa, R. Kitaura, S. Noro, Angew. Chem. 2004, 116, 2388;
Angew. Chem. Int. Ed. 2004, 43, 2334.
[9] a) R. Banerjee, A. Phan, B. Wang, C. Knobler, H. Furukawa, M.
OꢅKeeffe, O. M. Yaghi, Science 2008, 319, 939; b) M. Dinca, J. R.
Long, J. Am. Chem. Soc. 2005, 127, 9376; c) Y. W. Li, R. T. Yang,
J. Am. Chem. Soc. 2006, 128, 726.
[10] a) D. Farrusseng, S. Aguado, C. Pinel, Angew. Chem. 2009, 121,
7638; Angew. Chem. Int. Ed. 2009, 48, 7502; b) Y. K. Hwang,
D. Y. Hong, J. S. Chang, S. H. Jhung, Y. K. Seo, J. Kim, A.
Vimont, M. Daturi, C. Serre, G. Fꢃrey, Angew. Chem. 2008, 120,
4212; Angew. Chem. Int. Ed. 2008, 47, 4144; c) S. Hermes, M. K.
Schroter, R. Schmid, L. Khodeir, M. Muhler, A. Tissler, R. W.
Fischer, R. A. Fischer, Angew. Chem. 2005, 117, 6394; Angew.
Chem. Int. Ed. 2005, 44, 6237; d) H. Jiang, B. Liu, T. Akita, M.
Haruta, H. Sakurai, Q. Xu, J. Am. Chem. Soc. 2009, 131, 11302;
e) T. Ishida, M. Nagaoka, T. Akita, M. Haruta, Chem. Eur. J.
2008, 14, 8456; f) A. Henschel, K. Gedrich, R. Kraehnert, S.
Kaskel, Chem. Commun. 2008, 4192; g) Y. Y. Pan, B. Z. Yuan,
Y. W. Li, D. H. He, Chem. Commun. 2010, 46, 2280.
Received: January 30, 2010
Published online: April 29, 2010
À
Keywords: aryl chlorides · C C coupling ·
heterogeneous catalysis · metal–organic frameworks · palladium
[11] F. X. Llabres Xamena, A. Abad, A. Corma, H. Garcia, J. Catal.
2007, 250, 294.
.
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[12] G. Fꢃrey, C. Mellot-Draznieks, C. Serre, F. Millange, J. Dutour, S.
[17] H. Li, J. Chen, Y. Wan, W. Chai, F. Zhang, Y. Lu, Green Chem.
2007, 9, 273.
[18] C. Adamo, C. Amatore, I. Ciofini, A. Jutand, H. Lakmini, J. Am.
Chem. Soc. 2006, 128, 6829.
Surblꢃ, I. Margiolaki, Science 2005, 309, 2040.
[13] M. Kawano, T. Kawamichi, T. Haneda, T. Kojima, M. Fujita, J.
Am. Chem. Soc. 2007, 129, 15418.
[19] For alcohols as reducing agents in Ullmann homocoupling
reactions, see: a) J. Hassan, V. Penalva, L. Lavenot, C. Gozzi, M.
Lemaire, Tetrahedron 1998, 54, 13793; b) L. Shao, Y. Du, M.
Zeng, X. Li, W. Shen, S. Zuo, Y. Lu, X. Zhang, C. Qi, Appl.
Organometal. Chem. 2010, DOI: 10.1002/aoc.1635.
[20] Y. Wan, H. Wang, Q. Zhao, M. Klingstedt, O. Terasaki, D. Zhao,
J. Am. Chem. Soc. 2009, 131, 4541.
[14] Y. W. Li, R. T. Yang, Langmuir 2007, 23, 12937.
[15] a) S. Turner, O. I. Lebedev, F. Schroder, D. Esken, R. A. Fischer,
G. Van Tendeloo, Chem. Mater. 2008, 20, 5622; b) Y. E. Cheon,
M. P. Suh, Angew. Chem. 2009, 121, 2943; Angew. Chem. Int. Ed.
2009, 48, 2899.
[16] M. T. Reetz, J. G. de Vries, Chem. Commun. 2004, 1559.
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