A highly active catalytic system for Suzuki-Miyaura cross-coupling reactions of aryl and heteroaryl chlorides in water

Article abstract of DOI:10.1039/c2ob26463c

An easily available Pd(OAc)₂/(2-mesitylindenyl) dicyclohexylphosphine/Me(octyl)₃N⁺Cl^-/K ₃PO₄·3H₂O catalytic system was developed and it shows high catalytic activity in the Suzuki-Miyaura cross-coupling reaction of a diverse array of aryl and heteroaryl chlorides in water. Notably, this catalytic system also works with ultra-low loading of the catalyst with high turnover numbers.

Full text of DOI:10.1039/c2ob26463c

View Article Online / Journal Homepage / Table of Contents for this issue
Dynamic Article Links
Organic &
Biomolecular
Chemistry
Cite this: Org. Biomol. Chem., 2012, 10, 9410
www.rsc.org/obc
PAPER
A highly active catalytic system for Suzuki–Miyaura cross-coupling reactions
of aryl and heteroaryl chlorides in water†
Shu-Lan Mao,a Yue Sun,a Guang-Ao Yu,*a Cui Zhao,a Zhi-Jun Han,b Jia Yuan,a Xiaolei Zhu,a Qihua Yangc
and Sheng-Hua Liu*a
Received 26th July 2012, Accepted 17th October 2012
DOI: 10.1039/c2ob26463c
An easily available Pd(OAc)2/(2-mesitylindenyl)dicyclohexylphosphine/Me(octyl)3N+Cl−/K3PO4·3H2O
catalytic system was developed and it shows high catalytic activity in the Suzuki–Miyaura cross-coupling
reaction of a diverse array of aryl and heteroaryl chlorides in water. Notably, this catalytic system also
works with ultra-low loading of the catalyst with high turnover numbers.
have minimal environmental consequences and would ideally be
recyclable. However, despite the impressive progress, a number
Introduction
During the last two decades, there has been increasing interest in
the use of water as a solvent for many homogeneously catalyzed
reactions.1 Cost, environmental benefits, and safety are among
the reasons most often argued to justify the replacement of
organic solvents by water in organic transformations. The use of
water in Pd-catalyzed cross-coupling reactions goes back to the
early development of Suzuki–Miyaura cross-coupling reactions,2
with the first example being reported by Casalnuovo and Cala-
brese in 1990.3 Since then, a large number of strategies for
Suzuki–Miyaura cross-coupling reactions in water have been
developed, including microwave-heating,4 ultrasonic-irradiation,5
ligand-free methodology,6 the use of water-soluble catalysts,7 the
addition of organic co-solvents,8 surfactants9 or phase transfer
reagents,10 and several reviews have been devoted to this subject.11
Among them, the application of surfactants or phase transfer
reagents in the aqueous Suzuki–Miyaura cross-coupling reaction
has attracted increasing attention because of these reagents being
commercially available. In particular, Lipshutz and Ghorai have
developed the concept of a “designer” surfactant in recognition
of the fact that solvent effects can be crucial to the success of a
reaction.12 Moreover, from the green chemistry perspective,13
the choice of amphiphile would ideally be, in the Anastas sense,
“benign by design.”14 In other words, its use on any scale would
of challenges remain unresolved; importantly the coupling of the
readily available and low-cost aryl chlorides and heteroaryl
chlorides continues to pose difficulties,15 and only a few catalytic
systems are known to be capable of combining the advantage of
using water as a reaction medium for Suzuki–Miyaura cross-
coupling reactions of highly challenging aryl and heteroaryl
chlorides.16 As part of our ongoing interest in palladium-cata-
lyzed reactions,17 we report herein the Suzuki–Miyaura cross-
coupling reaction of aryl chlorides and heteroaryl chlorides with
arylboronic acids catalyzed by an air-stable and readily available
Pd(OAc)2/(2-mesitylindenyl)dicyclohexylphosphine/Me
(octyl)3N+Cl−/K3PO4·3H2O catalytic system in water.
Results and discussion
We initially investigated the reaction of chlorobenzene with
4-methoxyphenylboronic acid to establish the feasibility of our
strategy and to optimize the reaction conditions (Table 1). First
the reaction was conducted without any base and/or phosphine
ligand and no product was obtained. Then phosphine ligand L1
((2-mesitylindenyl)dicyclohexylphosphine) and K3PO4·3H2O
were used and a moderate yield of the coupling product was
observed (Table 1, entry 4), when widely used phase transfer
reagent TBAB (tetrabutylammonium bromide) was added, the
yield was improved slightly (Table 1, entry 5). When
Me(octyl)3N+Cl− was used instead of TBAB, the coupling
product was obtained in 98% yield (Table 1, entry 6). The ana-
logue ligand L2 ((2-phenylindenyl)dicyclohexylphosphinium
tetrafluoroborate) was less reactive and gave the coupling products
in lower yields (Table 1, entry 7). Biarylphosphines provided
excellent catalytic activity for Suzuki–Miyaura cross-coupling
reactions in organic solvents,18 we found that biarylphosphine
ligands (Scheme 1) can also be utilized in the Suzuki–Miyaura
cross-coupling reaction in water, providing good to excellent
aKey Laboratory of Pesticide & Chemical Biology, Ministry of
Education, College of Chemistry, Central China Normal University,
Wuhan 430079, People’s Republic of China.
E-mail: yuguang@mail.ccnu.edu.cn, chshliu@mail.ccnu.edu.cn
bDepartment of Chemistry, State Key Laboratory of Elemento-Organic
Chemistry, Nankai University, Tianjin 300071, People’s Republic of
China
cState Key Laboratory of Catalysis, Dalian Institute of Chemical
Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian
116023, People’s Republic of China
†Electronic supplementary information (ESI) available: Characterization
data for all coupling products. See DOI: 10.1039/c2ob26463c
9410 | Org. Biomol. Chem., 2012, 10, 9410–9417
This journal is © The Royal Society of Chemistry 2012

View Article Online
Table 1 Optimization of the reaction conditionsa
Entry
Ligand
Phase transfer reagent
Base
Time (h)
Yieldb (%)
1
2
3
4
5
6
7
8
—
—
L1
L1
L1
L1
L2
L3
L4
L5
L6
L7
L1
L1
L1
L1
L1
L1
L1
—
—
—
—
—
K3PO4·3H2O
—
8
8
8
8
8
8
8
8
8
8
8
8
1
1
1
1
1
1
1
0
0
0
K3PO4·3H2O
K3PO4·3H2O
K3PO4·3H2O
K3PO4·3H2O
K3PO4·3H2O
K3PO4·3H2O
K3PO4·3H2O
K3PO4·3H2O
K3PO4·3H2O
K3PO4·3H2O
KOAc
42
48
98
81
88
93
91
98
98
91
15
14
25
73
22
49
TBAB
Me(octyl)3N+Cl−
Me(octyl)3N+Cl−
Me(octyl)3N+Cl−
Me(octyl)3N+Cl−
Me(octyl)3N+Cl−
Me(octyl)3N+Cl−
Me(octyl)3N+Cl−
Me(octyl)3N+Cl−
Me(octyl)3N+Cl−
Me(octyl)3N+Cl−
Me(octyl)3N+Cl−
Me(octyl)3N+Cl−
Me(octyl)3N+Cl−
Me(octyl)3N+Cl−
9
10
11
12
13
14
15
16
17
18
19
KOH
K2CO3
Na2CO3
NaOH
Cs2CO3
a Reaction conditions: 1.0 mmol of chlorobenzene, 1.2 mmol of 4-methoxyphenyl-boronic acid, 1.0 mmol phase transfer reagent, 0.5 mol%
Pd(OAc)2, 1.5 mol% ligand, 3.0 mmol of base, 2.0 mL H2O, 100 °C. b GC yield.
chlorobenzene reacted efficiently with 4-methoxyphenylboronic
acid within 8 h, providing 95% yield of the desired product
(Table 2, entry 1). Suzuki–Miyaura cross-coupling reactions of
electron-donating substituents such as –CH3 and –OCH3 at the
ortho, meta and para positions with 4-methoxyphenylboronic
acid went smoothly, providing excellent yields of the expected
product (92–98% yield) (Table 2, entries 2–5). The reaction of
electron-rich para-chlorophenol or ortho-chloroaniline with
4-methoxyphenylboronic acid yields the desired product in moder-
ate to high yields (Table 2, entries 6 and 7). The reaction of aryl
chlorides bearing electron-withdrawing groups such as –NO2,
–CHO, –COCH3, and –CF3 also permits the cross-coupling reac-
tion with 4-methoxyphenylboronic acid, giving the required pro-
ducts in moderate to good yields under optimized reaction
conditions (Table 2, entries 8–14). In addition, the reaction of
Scheme 1 Buchwald-type biarylphosphines used in Suzuki–Miyaura
bulky 2-bromomesitylene with 4-methoxyphenylboronic acid
cross-coupling reactions.
provided the expected product in 90% yield (Table 2, entry 16).
This catalytic system can also be used in the cross-coupling
reactions of different arylboronic acids with aryl chlorides. For
example, the reaction of phenylboronic acid with chlorobenzene
went smoothly, providing biphenyl in 77% yield (Table 3, entry
1). Phenylboronic acid can also react efficiently with substituted
chlorobenzene, such as para-chloroanisole and 1-chloro-4-nitro-
benzene, giving the required products in moderate to good yields
(Table 3, entries 2 and 3). Even more, hindered 2-methylphenyl-
boronic acid and 1-naphthylboronic acid coupled well with aryl
chlorides, and afforded the corresponding biaryl products in
good to excellent yields (Table 3, entries 4–8).
yields of the expected product (Table 1, entries 8–12). Then
several bases were tested and moderate to excellent yields of the
coupling product were observed in the presence of Cs2CO3,
Na2CO3 and K3PO4·3H2O (Table 1, entries 13–19). To further
expand the application of ligand L1, the optimal reaction con-
ditions were established using Pd(OAc)2 (0.5 mol%)/L1(1.5 mol%)
as the catalyst, K3PO4·3H2O (3.0 equiv.) as the base, Me-
(octyl)3N+Cl− (1.0 equiv.) as the phase transfer reagent and
water (2.0 mL) as the solvent at 100 °C for 8 h.
Under the optimized reaction conditions, a wide array of aryl
chlorides reacted smoothly with 4-methoxyphenylboronic acid
to provide the corresponding products. For example,
Heterocyclic compounds are of particular interest to the
pharmaceutical industry.19 The applications of heterocyclic
This journal is © The Royal Society of Chemistry 2012
Org. Biomol. Chem., 2012, 10, 9410–9417 | 9411

View Article Online
Table 2 Suzuki–Miyaura cross-coupling reactions of aryl chlorides with 4-methoxyphenylboronic acida
Entry
1
Substrate
Product
Yieldb (%)
95
2
3
98
98
4
5
6
7
95
92
47
98
8
9
98
80
10
11
12
98
48
86
13
92
14
15
16
96
20
90
a Reaction conditions: 1.0 mmol of aryl chloride, 1.2 mmol of 4-methoxyphenyl boronic acid, 1.0 mmol Me(octyl)3N+Cl−, 0.5 mol% Pd(OAc)2,
1.5 mol% L1, 3.0 mmol of K3PO4·3H2O, 2.0 mL H2O, 100 °C, reaction time 8 h. b Isolated yield.
compounds in cross-coupling reactions remain a challenge.20 To
the best of our knowledge, only a few successful examples of
aqueous-phase Suzuki–Miyaura cross-coupling reactions of
heteroaryl chlorides are known.21 Thus, a need exists for the
development of efficient catalysts for the cross-coupling reac-
tions of heteroaryl chlorides with arylboronic acids in water. We
investigated the catalytic behavior of the Pd(OAc)2/(2-mesitylin-
denyl)dicyclohexylphosphine/Me(octyl)3N+Cl−/K3PO4·3H2O
9412 | Org. Biomol. Chem., 2012, 10, 9410–9417
This journal is © The Royal Society of Chemistry 2012

View Article Online
Table 3 Suzuki–Miyaura cross-coupling reactions of arylboronic acids with aryl halidesa
Entry
1
ArB(OH)2
Ar’X
Product
Yieldb (%)
77
2
3
4
83
76
79
5
6
7
95
81
88
8
85
a Reaction conditions: 1.2 mmol of arylboronic acid, 1.0 mmol of aryl chloride, 1.0 mmol Me(octyl)3N+Cl−, 0.5 mol% Pd(OAc)2, 1.5 mol% L1,
3.0 mmol of K3PO4·3H2O, 2.0 mL H2O, 100 °C, reaction time 8 h. b Isolated yield.
catalytic system in the cross-coupling reaction of heteroaryl
chlorides with arylboronic acids in water (Table 4). 2-Chloropyri-
dine and 3-chloropyridine underwent the cross-coupling reac-
tions with arylboronic acid, affording the corresponding desired
products in good to excellent yields (Table 4, entries 1–6). Typi-
cally, the coupling of heteroaryl chlorides bearing an unprotected
amino group is slowed down due to competitive binding of the
amino group to the Pd center of the catalyst. Catalyst deactiva-
tion has been noted with this kind of substrates.22 Interestingly,
our catalytic system was found to be active for the coupling of
unprotected aminochloropyridine (Table 4, entries 7–9). Other
heteroaryl chlorides such as 2-chloro-5-nitropyridine, 2-chloro-
pyrazine, 2-chloropyrimidine and 3,6-dichloropyridazine were
converted to the corresponding products in moderate yields
(Table 4, entries 10–13). It is also noteworthy that the present
protocol is applicable to the double cross-coupling reaction of
2,6-dichloropyrazine with 4-methoxyphenylboronic acid, provi-
ding the desired product in 92% yield (Table 4, entry 14). To
further extend the scope of our catalytic system, we carried out
the cross-coupling reactions of unactivated thiophene halides.
Unfortunately, 2-chlorothiophene did not couple under the
optimal conditions, the starting material remained, and the yield
was too low to be isolated. The cross-coupling reactions of
2- and 3-bromothiophenes with arylboronic acid proceeded very
well in satisfactory yields (Table 4, entries 15–21). Furthermore,
we investigated the coupling reaction of 2-thiophenylboronic
acid with aryl chlorides, low yields (10–22%) were obtained in
the case of chlorobenzene and para-chloroanisole (Table 4,
entries 22 and 23). However, for electron-deficient aryl chloride,
they could be coupled efficiently (Table 4, entry 24). These
results indicated that with a substituted thiophene, a possible
interaction between the sulfur element and the palladium
complex has a deactivation effect on the rate of the reaction.
To carry out an economical large-scale synthesis of pharma-
ceutical intermediates or other bulk fine chemicals, a low
loading catalyst is needed. To further study the efficiency of our
catalytic system, we then studied the TON of our catalytic
system at low loading (Table 5). For example, carrying out the
coupling reaction at a palladium loading of 0.005 mol% led to a
yield of 55% after 48 h. This corresponds to a TON of
11 000 mol (ArCl) mol (Pd)−1. When the palladium loading was
lowered to 0.0005 mol%, the coupling product was still obtained
in 61% yield after 48 h (TON = 120 000).
Conclusions
In conclusion, an easily available Pd(OAc)2/(2-mesitylindenyl)-
dicyclohexylphosphine/Me(octyl)3N+Cl−/K3PO4·3H2O catalytic
system was developed. This catalytic system was found to present
high activity in catalyzing Suzuki–Miyaura cross-coupling reactions
of a variety of aryl and heteroaryl chlorides including activated,
This journal is © The Royal Society of Chemistry 2012
Org. Biomol. Chem., 2012, 10, 9410–9417 | 9413

View Article Online
Table 4 Suzuki–Miyaura cross-coupling reactions of heteroaryl halides with arylboronic acidsa
Entry
1
RX
ArB(OH)2
Product
Yieldb (%)
91
2
3
98
84
4
91
5
6
96
87
7
8
9
62
55
55
10
11
70
37
12
41
13
14
43c
92c
15
16
17
82
91
95
9414 | Org. Biomol. Chem., 2012, 10, 9410–9417
This journal is © The Royal Society of Chemistry 2012

View Article Online
Table 4 (Contd.)
Entry
18
RX
ArB(OH)2
Product
Yieldb (%)
92
19
20
21
91
86
90
22
23
24
10
22
86
a Reaction conditions: 1.0 mmol of heteroaryl halide, 1.2 mmol of arylboronic acid, 1.0 mmol Me(octyl)3N+Cl−, 0.5 mol% Pd(OAc)2, 1.5 mol% L1,
3.0 mmol of K3PO4·3H2O, 2.0 mL H2O, 100 °C, reaction time 8 h. b Isolated yield. c 2.4 mmol of 4-methoxyphenylboronic acid.
indenyl)dicyclohexylphosphine17a and (2-phenylindenyl)-
Table 5 Suzuki–Miyaura coupling reactions using ultra-low loading of
catalyst
dicyclohexylphosphinium tetrafluoroborate17b were prepared
according to the reported procedures. Water was degassed
by sparging with nitrogen for at least 15 min before use.
All reactions were performed in a resealable screw cap Schlenk
flask (approx. 10 mL volume) in the presence of a Teflon
coated magnetic stirrer bar (3 mm × 50 mm). Silica gel (70–230
and 230–400 mesh) was used for column chromatography.
1H NMR and 13C NMR spectra were recorded on a Mercury-
Entry
Mol% Pd
Yield (%)
TON
Plus (400 MHz or 600 MHz) spectrometer. The
products described in GC yield were accorded to the authentic
samples/dodecane calibration standard from an Agilent 6890 GC
system. All yields reported refer to isolated yields of compounds
estimated to be greater than 95% purity as determined by capil-
lary gas chromatography (GC) or 1H NMR. Compounds
described in the literature were characterized by comparison
1
2
0.005
0.0005
55
61
11 000
120 000
deactivated and hindered substrates to afford the desired product
in moderate to high yields in water. Furthermore, the catalyst dis-
played exceptionally high turnover numbers. The work on
mechanistic features and further application of this catalytic
system in other reactions is currently ongoing in our laboratory.
1
of their H and/or 13C NMR spectra to the previously reported
data.
General procedures for reaction condition screenings
Experimental section
A Pd source (0.05 mmol), a phosphine ligand (0.15 mmol) and
a phase transfer reagent (10 mmol) were dissolved in water
(10 mL). The resulting solution was stirred at room temperature
for 5 minutes before immediate use. The aqueous solution of the
catalyst (1.0 mL) containing the Pd source (0.005 mmol), the
General considerations
Unless otherwise noted, all reagents were purchased from com-
mercial suppliers and used without purification. (2-Mesityl-
This journal is © The Royal Society of Chemistry 2012
Org. Biomol. Chem., 2012, 10, 9410–9417 | 9415

View Article Online
(c) C. O. Kappe, Angew. Chem., Int. Ed., 2004, 43, 6250;
(d) N. E. Leadbeater, Chem. Commun., 2005, 2881; (e) B. A. Roberts
and C. R. Strauss, Acc. Chem. Res., 2005, 38, 653; (f) C. J. Li, Angew.
Chem., Int. Ed., 2003, 42, 4856.
5 (a) A. L. F. de Souza, L. C. da Silva, B. L. Oliveira and
O. A. C. Antunes, Tetrahedron Lett., 2008, 49, 3895; (b) V. Poláčková,
M. Huťka and Š. Toma, Ultrason. Sonochem., 2005, 12, 99.
6 (a) M. Mondal and U. Bora, Green Chem., 2012, 14, 1873; (b) B. Basu,
K. Biswas, S. Kundu and S. Ghosh, Green Chem., 2010, 12, 1734;
(c) S. Shi and Y. Zhang, Green Chem., 2008, 10, 868; (d) T. Maegawa,
Y. Kitamura, S. Sako, T. Udzu, A. Sakurai, A. Tanaka, Y. Kobayashi,
K. Endo, U. Bora, T. Kurita, A. Kozaki, Y. Monguchi and H. Sajiki,
Chem.–Eur. J., 2007, 13, 5937.
7 (a) N. Liu, C. Liu and Z. Jin, Green Chem., 2012, 14, 592;
(b) A. N. Marziale, D. Jantke, S. H. Faul, T. Reiner, E. Herdtweck and
J. Eppinger, Green Chem., 2011, 13, 169; (c) C. A. Fleckenstein and
H. Plenio, Green Chem., 2007, 9, 1287; (d) R. Huang and
K. H. Shaughnessy, Organometallics, 2006, 25, 4105.
phosphine ligand (0.015 mmol) and the phase transfer reagent
(1.0 mmol) was loaded into a Schlenk tube equipped with a
Teflon-coated magnetic stir bar. Chlorobenzene (112 mg,
1.0 mmol), 4-methoxyphenylboronic acid (182 mg, 1.2 mmol),
base (3.0 mmol) and water (1.0 mL) were added. The tube was
evacuated and flushed with nitrogen three times, and then
placed in a preheated oil bath (100 °C) and stirred for the time
period as indicated in Table 1. After completion of the reaction,
the reaction tube was allowed to cool to room temperature. Ethyl
acetate (10 mL) and dodecane (22.6 mg, 0.1 mmol, internal stan-
dard) were added. The organic layer was subjected to GC analy-
sis. The GC yield obtained was previously calibrated by an
authentic sample/dodecane calibration curve. The product was
purified by column chromatography (hexane/ethyl acetate as
eluent).
8 (a) F. Li and T. S. A. Hor, Adv. Synth. Catal., 2008, 350, 2391;
(b) L. R. Moore, E. C. Western, R. Craciun, J. M. Spruell, D. A. Dixon,
K. P. O’Halloran and K. H. Shaughnessy, Organometallics, 2008, 27,
576; (c) P. Čapek, R. Pohl and M. Hocek, Org. Biomol. Chem., 2006, 4,
2278.
General procedure for Suzuki–Miyaura cross-coupling reaction
in water
9 (a) J. Zhi, D. Song, Z. Li, X. Lei and A. Hu, Chem. Commun., 2011, 47,
10707; (b) B. H. Lipshutz, S. Ghorai, A. R. Abela, R. Moser,
T. Nishikata, C. Duplais, A. Krasovskiy, R. D. Gaston and
R. C. Gadwood, J. Org. Chem., 2011, 76, 4379; (c) B. H. Lipshutz,
T. B. Petersen and A. R. Abela, Org. Lett., 2008, 10, 1333.
10 (a) A. Krasovskiy, I. Thomé, J. Graff, V. Krasovskaya, P. Konopelski,
C. Duplais and B. H. Lipshutz, Tetrahedron Lett., 2011, 2203;
(b) R. B. Bedford, M. E. Blake, C. P. Butts and D. Holder, Chem.
Commun., 2003, 466; (c) N. E. Leadbeater and M. Marco, Org. Lett.,
2002, 4, 2973.
11 (a) M. Carril, R. SanMartin and E. Domínguez, Chem. Soc. Rev., 2008,
37, 639; (b) K. H. Shaughnessy, Eur. J. Org. Chem., 2006, 1827;
(c) L. Bai and J. X. Wang, Curr. Org. Chem., 2005, 9, 535;
(d) K. H. Shaughnessy and R. B. DeVasher, Curr. Org. Chem., 2005, 9,
585; (e) V. Polshettiwar, A. Decottignies, C. Len and A. Fihri, Chem-
SusChem., 2010, 3, 502.
12 B. H. Lipshutz and S. Ghorai, Aldrichimica Acta, 2008, 41, 59.
13 R. A. Sheldon, I. W. C. E. Arends and U. Hanefeld, Green Chemistry and
Catalysis, Wiley-VCH, Weinheim, Germany, 2007.
Pd(OAc)2 (11 mg, 0.05 mmol), ligand 1 (65 mg, 0.15 mmol)
and methyltrioctylammonium chloride (4.04 g, 10 mmol) were
dissolved in water (10 mL). The resulting solution was stirred at
room temperature for 5 minutes before immediate use. The
aqueous solution of the catalyst (1.0 mL) containing Pd(OAc)2
(1.1 mg, 0.005 mmol), ligand 1 (6.5 mg, 0.015 mmol) and
methyltrioctylammonium chloride (404 mg, 1.0 mmol) was
loaded into a Schlenk tube equipped with a Teflon-coated mag-
netic stir bar. Aryl chloride (1.0 mmol), arylboronic acid
(1.2 mmol), base (3.0 mmol) and water (1.0 mL) were added.
The tube was evacuated and flushed with nitrogen three times,
and then placed in a preheated oil bath (100 °C) for 8 h. After
completion of the reaction, the reaction tube was allowed to cool
to room temperature, water was drawn with a dropper and the
reaction mixture was adsorbed onto silica gel, and then purified
by column chromatography (hexane/ethyl acetate as eluent) to
afford the desired product.
14 P. T. Anastas and C. A. Farris, Benign by Design: Alternative Synthetic
Design for Pollution Prevention, ACS Symposium Series 557, American
Chemical Society, Washington, DC, 1994.
15 A. Fihri, D. Luart, C. Len, A. Solhy, C. Chevrin and V. Polshettiwar,
Dalton Trans., 2011, 40, 3116.
16 (a) B. Karimi and P. F. Akhavan, Chem. Commun., 2011, 47, 7686;
(b) J. Han, Y. Liu and R. Guo, J. Am. Chem. Soc., 2009, 131, 2060;
(c) B. Karimi, D. Elhamifar, J. H. Clark and A. J. Hunt, Chem.–Eur. J.,
2010, 16, 8047; (d) B. Yuan, Y. Pan, Y. Li, B. Yin and H. Jiang, Angew.
Chem., Int. Ed., 2010, 49, 4054; (e) B. Karimi and P. F. Akhavan, Chem.
Commun., 2009, 3750; (f) B. J. Gallon, R. W. Kojima, R. B. Kaner and
P. L. Diaconescu, Angew. Chem., Int. Ed., 2007, 46, 7151;
(g) K. W. Anderson and S. L. Buchwald, Angew. Chem.. Int. Ed., 2005,
44, 6173; (h) M. E. Hanhan, R. M. Máñez and J. V. Ros-Lis, Tetrahedron
Lett., 2012, 53, 2388; (i) D.-H. Lee, Y. H. Lee, D. I. Kim, Y. Kim,
W. T. Lim, J. M. Harrowfield, P. Thuéry, M.-J. Jin, Y. C. Park and
I.-M. Lee, Tetrahedron, 2008, 64, 7178; ( j) C. Fleckenstein, S. Roy,
S. Leuthäuβer and H. Plenio, Chem. Commun., 2007, 2870.
Acknowledgements
The authors acknowledge financial support from the National
Natural Science Foundation of China (Nos. 21072071,
20931006, 21072070), the Program for Changjiang Scholars and
Innovative Research Team in University (No. IRT0953), the
Program for Academic Leader in Wuhan Municipality (No.
201271130441) and the Science Foundation of Central China
Normal University.
17 (a) X. Hao, J. Yuan, G.-A. Yu, M.-Q. Qiu, N.-F. She, Y. Sun, C. Zhao,
S.-L. Mao, J. Yin and S.-H. Liu, J. Organomet. Chem., 2012, 706–707,
99; (b) L. Chen, G.-A. Yu, F. Li, X. Zhu, B. Zhang, R. Guo, X. Li,
Q. Yang, S. Jin, C. Liu and S.-H. Liu, J. Organomet. Chem., 2010, 695,
1768.
18 R. Martin and S. L. Buchwald, Acc. Chem. Res., 2008, 41, 1461.
19 (a) D. Zhao, J. You and C. Hu, Chem.–Eur. J., 2011, 17, 5466;
(b) V. F. Slagt, A. H. M. de Vries, J. G. de Vries and R. M. Kellogg, Org.
Process Res. Dev., 2010, 14, 30; (c) R. A. Hughes and C. J. Moody,
Angew. Chem., Int. Ed., 2007, 46, 7930.
20 (a) K. L. Billingsley and S. L. Buchwald, Angew. Chem., Int. Ed., 2008,
47, 4695; (b) R. Ghosh, N. N. Adarsh and A. Sarkar, J. Org. Chem.,
2010, 75, 5320; (c) K. Billingsley and S. L. Buchwald, J. Am. Chem.
Soc., 2007, 129, 3358; (d) A. Thakur, K. Zhang and J. Louie, Chem.
Commun., 2012, 48, 203; (e) K. L. Billingsley, K. W. Anderson and
Notes and references
1 (a) M. O. Simon and C. J. Li, Chem. Soc. Rev., 2012, 41, 1415;
(b) M. Lamblin, L. Nassar-Hardy, J. C. Hierso, E. Fouquet and
F. X. Felpin, Adv. Synth. Catal., 2010, 352, 33; (c) R. N. Butler and
A. G. Coyne, Chem. Rev., 2010, 110, 6302; (d) K. H. Shaughnessy,
Chem. Rev., 2009, 109, 643; (e) U. M. Lindström, Chem. Rev., 2002,
102, 2751.
2 N. Miyaura, K. Yamada, H. Suginome and A. Suzuki, J. Am. Chem. Soc.,
1985, 107, 972.
3 A. L. Casalnuovo and J. C. Calabrese, J. Am. Chem. Soc., 1990, 112,
4324.
4 (a) D. Dallinger and C. O. Kappe, Chem. Rev., 2007, 107, 2563;
(b) V. Polshettiwar and R. S. Varma, Acc. Chem. Res., 2008, 41, 629;
9416 | Org. Biomol. Chem., 2012, 10, 9410–9417
This journal is © The Royal Society of Chemistry 2012

View Article Online
S. L. Buchwald, Angew. Chem., Int. Ed., 2006, 45, 3484; (f) T. Noël and
A. J. Musacchio, Org. Lett., 2011, 13, 5180; (g) N. Kudo, M. Perseghini
and G. C. Fu, Angew. Chem., Int. Ed., 2006, 45, 1282.
M. J. Jin, Adv. Synth. Catal., 2009, 351, 2912; (c) K. W. Anderson and
S. L. Buchwald, Angew. Chem., Int. Ed., 2005, 44, 6173; (d) X.-X. Zhou
and L.-X. Shao, Synthesis, 2011, 3138; (e) D.-H. Lee, J.-Y. Jung and
M.-J. Jin, Green Chem., 2010, 12, 2024.
21 (a) S. Lou and G. C. Fu, Adv. Synth. Catal., 2010, 352, 2081;
(b) D. H. Lee, M. Choi, B. W. Yu, R. Ryoo, A. Taher, S. Hossain and
22 T. Itoh and T. Mase, Tetrahedron Lett., 2005, 46, 3573.
This journal is © The Royal Society of Chemistry 2012
Org. Biomol. Chem., 2012, 10, 9410–9417 | 9417