TBAB-promoted ligand-free copper-catalyzed cross-coupling reactions of aryl halides with arylboronic acids

Article abstract of DOI:10.1055/s-2007-965958

Tetrabutylammonium bromide (TBAB) was found to improve the ligand-free copper-catalyzed cross-couplings of aryl halides with arylboronic acids. In the presence of 10 mol% of CuI and 20 mol% of TBAB, a variety of aryl halides underwent the coupling with arylboronic acids smoothly to afford the corresponding products in moderate to good yields. Georg Thieme Verlag Stuttgart.

Full text of DOI:10.1055/s-2007-965958

9
84
PAPER
TBAB-Promoted Ligand-Free Copper-Catalyzed Cross-Coupling Reactions
of Aryl Halides with Arylboronic Acids
C
J
ross-Cou
i
pling R
n
eactions of
-
A
ryl
H
al
H
ides with
A
rylboro
e
nic Acids ng Li,* Ji-Lan Li, Ye-Xiang Xie
Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and
Chemical Engineering, Hunan Normal University, Changsha 410081, P. R. of China
Fax +86(731)8872531; E-mail: jhli@hunnu.edu.cn
Received 5 December 2006; revised 16 January 2007
DMSO. Moreover, both electron-neutral and electron-rich
Abstract: Tetrabutylammonium bromide (TBAB) was found to
aryl bromides could undergo the reaction in the presence
of a catalytic amount of CuI and TBAB. In addition, het-
improve the ligand-free copper-catalyzed cross-couplings of aryl
halides with arylboronic acids. In the presence of 10 mol% of CuI
eroaryl bromides and vinyl halides were also suitable sub-
and 20 mol% of TBAB, a variety of aryl halides underwent the cou-
pling with arylboronic acids smoothly to afford the corresponding strates under the same conditions. Here, we wish to report
products in moderate to good yields.
TBAB-promoted CuI-catalyzed Suzuki–Miyaura cross-
Key words: tetrabutylammonium bromide, copper(I) iodide, aryl coupling reaction of aryl halides and vinyl halides with
halide, arylboronic acid, Suzuki–Miyaura cross-coupling reaction
arylboronic acids under ligand-free conditions
Equation 1).
(
CuI, TBAB
Cs2CO3, DMSO
The Suzuki–Miyaura cross-coupling reaction has become
a powerful approach for the formation of carbon–carbon
bonds, as the resulting biaryl products are important struc-
tural subunits in numerous natural products and pharma-
ceuticals as well as valuable building blocks in organic
ArX
+
Ar'B(OH)2
Ar Ar'
Ar, 135–140 °C
Ar = aryl, heteroaryl, vinyl X = I, Br
Ar' = aryl, heteroaryl
1
Equation 1
synthesis. The most common catalytic system is Pd com-
bined with a ligand (often a phosphine). However, both
the Pd catalysts and ligands are expensive. From the view
of economic and environmental points, development of
cheaper metals as catalysts in place of Pd is an attractive
route, in spite of the recovery as well as recycling of the
As shown in Table 1, the reaction of 1-bromo-4-methoxy-
benzene (1a) with phenylboronic acid (2a) was first tested
to screen the reaction conditions. We were happy to ob-
serve that TBAB could improve the reaction (entries 1–3).
Without TBAB, only a trace amount of the target product
1
–7
Pd catalyst. Although copper has been applied as cata-
lyst in many cross-coupling transformations, little atten-
tion has been paid to the use of copper as catalyst for
3
was isolated in DMF using CuI as the catalyst and
Cs CO as the base (entry 1), whereas the yield of 3 was
2
3
2
,4–7
Suzuki–Miyaura cross-coupling reaction.
Rothenberg
enhanced to 46% when 20 mol% of TBAB was added (en-
try 2). The presence of one equivalent of TBAB increased
the yield slightly (entry 3). Subsequently, a series of sol-
vents were examined (entries 2 and 4–9). It was found that
DMSO gave the best yield. A number of other copper cat-
alysts, including CuBr, Cu O and Cu(OAc) , were also in-
and co-workers first reported that the reactions of a num-
ber of aryl halides with phenylboronic acid catalyzed by
copper or copper-based nanocolloids were conducted ef-
ficiently in moderate to excellent yields. However, only
the couplings of aryl iodides were investigated when the
2
2
4
catalyst was copper alone. Very recently, we also de-
vestigated, and they were all less effective than CuI with
regard to the yields (entries 10–12). The other phase-
scribed that CuI combined with DABCO was an effective
and inexpensive catalytic system for the Suzuki–Miyaura
cross-coupling reaction, and the scope was extended to
transfer catalysts, TBABF and TBAI, were inferior to
4
TBAB based on the yield (entries 13 and 14). Finally, the
amount of CuI was also tested, and the results indicated
that the yield of 3 was increased slightly in the presence of
6
,7
aryl bromides. However, a stoichiometric amount of
CuI together with tetrabutylammonium bromide (TBAB)
was necessary for the couplings of both electron-neutral
and electron-rich aryl bromides to provide satisfactory
5
0 mol% of CuI (entry 15).
The couplings of a variety of aryl halides with arylboronic
acids were conducted smoothly in the presence of CuI and
TBAB in moderate to good yields, and the results are
summarized in Table 2. It was observed that substrate 1a
could also coupled with other arylboronic acids 2b and 2c
to give the corresponding desired products in moderate to
high yields using CuI combined with TBAB as the cata-
lytic system and DMSO as the solvent (entries 1 and 2).
Unfortunately, coupling of substrate 1a with a bulky bo-
ronic acid 2d was unsuccessful (entry 3). Under the stan-
7
yields. As a result, we decided to further evaluate the role
of TBAB in the copper-catalyzed Suzuki–Miyaura cross-
coupling reaction. To our delight, the copper-catalyzed
Suzuki–Miyaura cross-coupling could be carried out
smoothly without any ligand in the presence of TBAB and
SYNTHESIS 2007, No. 7, pp 0984–0988
x
x
.
x
x
.2
0
0
7
Advanced online publication: 28.02.2007
DOI: 10.1055/s-2007-965958; Art ID: F19706SS
Georg Thieme Verlag Stuttgart · New York
©

PAPER
Cross-Coupling Reactions of Aryl Halides with Arylboronic Acids
985
Table 1 Copper-Catalyzed Cross-Coupling of 1-Bromo-4-meth-
oxybenzene (1a) with Phenylboronic Acid (2a)
25–27). Gratifyingly, the couplings of vinyl halides 1q–s
a
with boronic acid 2a were carried out smoothly in the
presence of 10 mol% of CuI and 20 mol% of TBAB (en-
tries 28–30).
MeO
Br
+
B(OH)2
MeO
1a
2a
3
Table 2 The Suzuki–Miyaura Cross-Coupling Reaction Catalyzed
Entry
Copper catalyst Solvent
Time (h) Yield (%)b
by CuI/TBAB Catalytic Systema
1c
CuI, TBAB
CuI
CuI
CuI
CuI
CuI
CuI
CuI
CuI
CuI
CuBr
DMF
24
24
24
20
24
24
24
24
20
24
24
24
24
24
24
trace
46
X
+
ArB(OH)2
Ar
R
Cs2CO3, DMSO
Ar, 135–140 °C
R
2
DMF
3d
4
DMF
48
Time Yield (%)b
Entry Aryl halide
ArB(OH)2
(
h)
(product)
DMSO
dioxane
EtOH
55
5
trace
28
1
2
MeO
1a
Br
MeO
B(OH)2 22
48 (4)
6
2b
F
7
m-xylene
–
trace
13
1a
B(OH)2
20
24
88 (5)
8e
9f
2c
Me
Me
DMSO–DMF
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
53
B(OH)2
B(OH)2
3
1a
trace (6)
1
1
1
1
1
0
1
2
30
Cu O
trace
29
2
2d
Cu(OAc)2
4
5
6
2
O N
I
18
20
20
messy (7)
70 (8)
3g
CuI
50
1
b
O
2a
2a
4h
CuI
CuI
39
I
1
a
5i
58
1
1
c
Unless otherwise indicated, the reaction conditions were as follows:
I
2a
96 (9)
1
a (0.5 mmol), 2a (0.65 mmol), [Cu] (10 mol%), TBAB (Bu NBr, 20
mol%), Cs CO (2 equiv), and solvent (2 mL) at 135–140 °C under
argon.
Isolated yield.
Without TBAB.
TBAB (1 equiv).
TBAB (1.5 g).
DMSO–DMF (1:1, 2 mL).
TBABF (Bu NBF , 20 mol%) instead of TBAB.
4
2
3
d
1d
7
8
2b
2c
22
20
87 (3)
b
c
d
e
f
1d
98 (10)
9
0
1
2
1d
1d
18
40
18
16
65 (11)
83 (12)
70 (13)
95 (14)
B(OH)2
B(OH)2
O
g
h
i
4
4
4
2e
TBAI ((Bu NI, 20 mol%) instead of TBAB.
CuI (50 mol%).
4
1
1
1
S
2
f
dard reaction conditions, the other aryl halides including
aryl iodides 1c–g and aryl bromides 1i–n, all work suc-
cessfully with arylboronic acids. For instance, treatment of
iodobenzene (1d) with arylboronic acids 2a–c and 2e–g,
N
B(OH)2
1d
2
g
Me
I
2a
1
0 mol% of CuI and 20 mol% of TBAB in DMSO afford-
ed the corresponding products 9, 3 and 10–13 in 96%,
7%, 98%, 65%, 83%, and 70% yields, respectively (en-
1
e
I
8
1
1
3
4
2a
24
50 (15)
Me
tries 6–11). We were delighted to note that heteroaryl bro-
mides 1m and 1n were also suitable substrates providing
moderate yields (entries 23 and 24). To our surprise, aryl
halides 1b, 1c, 1h and 1i bearing electron-withdrawing
groups are less selective toward the cross-coupling reac-
1f
MeO
I
2a
2a
21
21
65 (3)
93 (3)
1g
1g
tion under the standard conditions, and the reactions of 15c
substrates 1b and 1h were messy (entries 4, 5, 16 and 17).
Unfortunately, aryl chlorides 1o and 1p were still unsuit-
able substrates for the copper-catalyzed reaction (entries
Synthesis 2007, No. 7, 984–988 © Thieme Stuttgart · New York

9
86
J.-H. Li et al.
PAPER
Table 2 The Suzuki–Miyaura Cross-Coupling Reaction Catalyzed
by CuI/TBAB Catalytic System (continued)
A working mechanism is proposed as outlined in
a
1,2
Scheme 1. The reaction of intermediate 21, a four-cen-8
CuI, TBAB
tered transition state proposed by Castro and Stephens,
X
+
ArB(OH)2
Ar
with aryl halides afforded intermediate 22. Transmetala-
R
Cs2CO3, DMSO
Ar, 135–140 °C
R
tion of intermediate 22 with ArB(OH) 2 then occurred to
2
form intermediate 23, followed by reductive elimination
of intermediate 23 to give the coupled product and regen-
eration of the active copper(I) complex 21. We deduce
that TBAB may play two roles in the present reaction on
the basis of the previously reported results on the effect of
TBAB:1 (i) a promoter or/and a ligand to activate and
stabilize the active Cu species; (ii) phase-transfer catalyst
for the inorganic base/solvent/substrate/product phases.
Study of the accurate role of TBAB is in progress.
Entry Aryl halide
ArB(OH)2
Time Yield (%)b
(
h)
(product)
O2N
Br
Br
1
1
1
6
7
8
2a
2a
2a
20
18
20
messy (7)
,2,9
1h
O
60 (8)
75 (9)
1
1
i
Br
CuI
L
j
1
2
9
0
1j
2b
2f
21
21
65 (3)
L3CuI
2
1
ArX + base
1j
96 (12)
Ar Ar'
-20
1
3
L + baseX
L = solvent, TBAB, etc.
2
2
1
2
Me
Br
2a
2a
20
21
71 (14)
60 (16)
2L
1k
Me
L
Ar'
Cu
I
Cu
Br
L
Ar
L
Ar
I
Me
22
2
3
1l
Br
Ar'B(OH)2 + base
L + base-B(OH)2
2
2
3
4
2a
2a
20
20
55 (17)
65 (18)
N
Scheme 1 A possible mechanism for the copper-catalyzed Suzuki–
Miyaura reaction
1
m
N
N
In summary, an inexpensive and ligand-free copper-cata-
lyzed Suzuki–Miyaura cross-coupling reaction has been
developed. In the presence of 10 mol% of CuI and 20
mol% of TBAB, a variety of aryl halides underwent the
coupling with arylboronic acids smoothly to afford the
corresponding products in moderate to good yields. Sev-
eral features are established on the base of these results:
Br
1
n
O2N
Cl
2
2
2
5
2a
2a
2a
24
24
24
trace (7)
10 (7)
1
o
1o
6c
(
1) TBAB has a fundamental influence on the reaction.
7c
8
trace (14)
Me
Cl
Without TBAB, only trace amount of the target product 3
1
1
1
1
p
q
r
s
was isolated in DMF using CuI as the catalyst and Cs CO3
2
as the base (entry 1 in Table 1), whereas the yield of 3 was
enhanced to 46% when 20 mol% of TBAB was added (en-
try 2 in Table 1). (2) The present reaction showed excel-
lent substituent tolerance, and the scope was extended to
the less activated aryl bromides and vinyl bromides. (3)
CuI combined with TBAB is significantly inexpensive
and readily available, which emerged as an attractive al-
ternative to the palladium/phosphine ligand system for the
Suzuki cross-coupling reaction. As a result, further appli-
cation of the catalytic system in other transformations
should be considerably attractive.
2
2
2a
2a
2a
24
24
24
75 (19)
58 (19)
53 (20)
I
9d
0
Br
Br
3
a
Reaction conditions: 1 (0.5 mmol), 2 (0.65 mmol), CuI (10 mol%),
TBAB (20 mol%), Cs CO (2 equiv) and DMSO (2 mL) at 135–
2
3
1
40 °C under argon.
Isolated yield.
CuI (50 mol%).
b
NMR spectroscopy was performed on an INOVA-400 (Varian), an
INOVA-500 (Varian) or an AMX-300 (Bruker) spectrometer oper-
c
d
1
13
Ratio of E/Z isomer is 9:1 as determined by GC-MS analysis.
ating at 400 MHz ( H NMR) and 100 MHz ( C NMR), 500 MHz
1
13
1
(
H NMR) and 125 MHz ( C NMR), or 300 MHz ( H NMR) and
Synthesis 2007, No. 7, 984–988 © Thieme Stuttgart · New York

PAPER
Cross-Coupling Reactions of Aryl Halides with Arylboronic Acids
987
1
3
13
7
5 MHz ( C NMR). TMS was used an internal standard and CDCl
C NMR (75 MHz, CDCl ): d = 142.0, 128.7, 128.6, 127.3, 127.2,
3
3
was used as the solvent. Mass spectrometric analysis was performed
on a Shimadzu GCMS-QP 2010 instrument.
127.1, 123.7, 111.6.
+
LRMS (EI, 70 eV): m/z (%) = 144 (M , 100).
TBAB-Promoted CuI -Catalyzed Suzuki–Miyaura Cross-
Coupling Reaction
-Phenylthiophene (12)13
H NMR (400 MHz, CDCl ): d = 7.61–7.57 (m, 2 H), 7.35 (t, J = 7.6
Hz, 2 H), 7.29–7.23 (m, 2 H), 7.05 (t, J = 4.0 Hz, 1 H).
2
2
1
3
A mixture of aryl halide 1 (0.5 mmol), arylboronic acid 2 (0.65
mmol), CuI (10 mol%), TBAB (20 mol%), Cs CO (2 equiv) and
2
3
1
3
C NMR (100 MHz, CDCl ): d = 144.4, 134.3, 128.8, 127.9, 127.4,
DMSO (2 mL) was added into a Schlenk tube under argon. The
mixture was then stirred at 135–140 °C for the desired time until
complete consumption of starting material as monitored by TLC.
3
1
25.9, 124.7, 123.0.
+
LRMS (EI, 70 eV): m/z (%) = 160 (M , 100).
The mixture was filtered, poured into Et O (10 mL), washed with
2
brine (5 × 3 mL), and the filtrate was extracted with Et O (3 × 5
14
2
4-Phenylpyridine (13)
mL). The solvent was evaporated and the residue was purified by
flash column chromatography (hexane or hexane–EtOAc) to afford
the desired coupled products (Table 2).
1
H NMR (500 MHz, CDCl ): d = 8.69 (d, J = 6.1 Hz, 2 H), 7.67 (d,
J = 7.4 Hz, 2 H), 7.54–7.46 (m, 5 H).
3
1
3
C NMR (125 MHz, CDCl ): d = 150.2, 148.4, 138.2, 129.1, 129.0,
3
-Methoxybiphenyl (3)3,4
127.0, 121.6.
4
1
+
H NMR (500 MHz, CDCl ): d = 7.60–7.56 (m, 4 H), 7.46 (t, J = 7.8
LRMS (EI, 70 eV): m/z (%) = 155 (M , 100).
3
Hz, 2 H), 7.34 (t, J = 7.5 Hz, 1 H), 7.02 (d, J = 9.0 Hz, 2 H), 3.89 (s,
3
,4
3
H).
4-Methylbiphenyl (14)
1
1
3
H NMR (400 MHz, CDCl
J = 8.0 Hz, 2 H), 7.42 (t, J = 7.6 Hz, 2 H), 7.31 (t, J = 7.6 Hz, 1 H),
.24 (d, J = 8.0 Hz, 2 H), 2.38 (s, 3 H).
): d = 7.59 (t, J = 7.6 Hz, 2 H), 7.49 (d,
3
C NMR (125 MHz, CDCl ): d = 159.2, 140.9, 133.8, 128.7, 128.2,
3
1
26.8, 126.7, 114.2, 55.4.
7
1
+
LRMS (EI, 70 eV): m/z (%) = 184 (M , 100).
3
C NMR (100 MHz, CDCl ): d = 141.1, 138.3, 137.0, 129.5, 128.7,
3
,4¢-Dimethoxybiphenyl (4)10
127.3, 127.2, 127.0, 21.1.
4
1
+
H NMR (300 MHz, CDCl ): d = 7.48 (d, J = 8.4 Hz, 4 H), 6.95 (d,
LRMS (EI, 70 eV): m/z (%) = 168 (M , 100).
3
J = 8.87 Hz, 4 H), 3.84 (s, 6 H).
1
1
1
3
2-Methylbiphenyl (15)
C NMR (100 MHz, CDCl ): d = 158.7, 133.5, 127.7, 114.1, 59.3.
3
1
H NMR (400 MHz, CDCl ): d = 7.40 (t, J = 7.2 Hz, 2 H), 7.32 (t,
J = 6.8 Hz, 3H), 7.25–7.23 (m, 4 H), 2.27 (s, 3 H).
3
+
LRMS (EI, 70 eV): m/z (%) = 214 (M , 100).
13C NMR (100 MHz, CDCl
128.0, 127.2, 126.7, 125.7, 125.6, 20.4.
): d = 141.9, 135.3, 130.3, 129.8, 129.2,
-Fluoro-4¢-methoxybiphenyl (5)11
3
4
1
H NMR (300 MHz, CDCl ): d = 7.50–7.45 (m, 4 H), 7.09 (t, J = 8.4
3
+
Hz, 2 H), 6.96 (d, J = 8.7 Hz, 2 H), 3.83 (s, 3 H).
LRMS (EI, 70 eV): m/z (%) = 168 (M , 100).
1
3
C NMR (100 MHz, CDCl ): d = 163.7, 160.4, 159.0, 132.7, 128.2
3
,5-Dimethylbiphenyl (16)15
3
(
d, J = 9.3 Hz, 1 C), 128.0, 115.5 (d, J = 28.2 Hz, 1 C), 114.2, 55.3.
1
H NMR (400 MHz, CDCl ): d = 7.59 (d, J = 8.4 Hz, 2 H), 7.44–
3
+
LRMS (EI, 70 eV): m/z (%) = 202 (M , 100).
7
.40 (m, 2 H), 7.31–7.28 (m, 1 H), 7.19 (d, J = 8.4 Hz, 2 H), 6.98
(
d, J = 9.2 Hz, 1 H), 2.37 (s, 3 H), 2.35 (s, 3 H).
1
-Biphenyl-4-ylethanone (8)3,4
13C NMR (100 MHz, CDCl
27.2, 127.1, 125.1, 21.4.
): d = 141.5, 138.1, 128.9, 128.7, 127.9,
1
3
H NMR (300 MHz, CDCl ): d = 8.04 (d, J = 8.4 Hz, 2 H), 7.69 (d,
J = 8.4 Hz, 2 H), 7.64 (d, J = 7.6 Hz, 2 H), 7.50–7.40 (m, 3 H), 2.64
3
1
+
(
s, 3 H).
LRMS (EI, 70 eV): m/z (%) = 182 (M , 100).
1
3
C NMR (75 MHz, CDCl ): d = 198.1, 146.1, 140.2, 136.2, 130.1,
3
-Phenylpyridine (17)14
H NMR (400 MHz, CDCl ): d = 8.85 (s, 1 H), 8.59 (d, J = 6.4 Hz,
H), 7.88 (d, J = 12.0 Hz, 1 H), 7.60 (d, J = 8.4 Hz, 2 H), 7.49 (t,
3
1
29.2, 128.6, 127.6, 118.5, 27.0.
1
3
+
LRMS (EI, 70 eV): m/z (%) = 196 (M , 100).
1
J = 7.2 Hz, 2 H), 7.43–7.35 (m, 2 H).
Biphenyl (9)10
13C NMR (100 MHz, CDCl
29.0, 128.1, 127.1, 123.5.
): d = 148.4, 148.3, 137.8, 136.6, 134.3,
1
3
H NMR (300 MHz, CDCl ): d = 7.59 (d, J = 8.4 Hz, 4 H), 7.43 (t,
J = 7.2 Hz, 4 H), 7.36 (t, J = 7.8 Hz, 2 H).
3
1
+
1
3
LRMS (EI, 70 eV): m/z (%) = 155 (M , 100).
C NMR (75 MHz, CDCl ): d = 141.6, 129.1, 127.6, 127.5.
3
+
LRMS (EI, 70 eV): m/z (%) = 154 (M , 100).
-Phenylpyrimidine (18)14
5
1
H NMR (400 MHz, CDCl ): d = 9.21 (s, 1 H), 8.96 (s, 2 H), 7.58
3
4
-Fluorobiphenyl (10)4
(
d, J = 8.8 Hz, 2 H), 7.53 (t, J = 8.8 Hz, 2 H), 7.47 (t, J = 7.2 Hz, 1
1
H NMR (400 MHz, CDCl ): d = 7.57–7.53 (m, 4 H), 7.44 (t, J = 7.6
Hz, 2 H), 7.35 (t, J = 7.2 Hz, 1 H), 7.13 (t, J = 8.8 Hz, 2 H).
3
H).
1
3
C NMR (100 MHz, CDCl ): d = 157.3, 154.8, 134.2, 134.1, 129.3,
3
1
3
C NMR (100 MHz, CDCl ): d = 163.7, 161.2, 140.2, 137.3, 128.8,
3
128.9, 126.7.
1
27.2, 115.8, 115.6.
+
LRMS (EI, 70 eV): m/z (%) = 156 (M , 100).
+
LRMS (EI, 70 eV): m/z (%) = 172 (M , 100).
(
E)-1,2-Diphenylethene (19)16
2
-Phenylfuran (11)12
1
H NMR (300 MHz, CDCl ): d = 7.51 (d, J = 8.4 Hz, 4 H), 7.35 (t,
3
1
H NMR (300 MHz, CDCl ): d = 7.67 (d, J = 8.8 Hz, 1 H), 7.60 (d,
3
J = 7.2 Hz, 4 H), 7.27 (t, J = 6.3 Hz, 2 H), 7.11 (s, 2 H).
J = 8.8 Hz, 2 H), 7.46–7.34 (m, 5 H).
1
3
C NMR (125 MHz, CDCl ): d = 137.4, 128.8, 128.7, 127.6, 126.5.
3
Synthesis 2007, No. 7, 984–988 © Thieme Stuttgart · New York

9
88
J.-H. Li et al.
PAPER
+
LRMS (EI, 70 eV): m/z (%) = 180 (M , 100).
(4) For papers on the copper-catalyzed Suzuki–Miyaura cross-
coupling reaction, see: (a) Thathagar, M. B.; Beckers, J.;
Rothenberg, G. J. Am. Chem. Soc. 2002, 124, 11858.
(b) Thathagar, M. B.; Beckers, J.; Rothenberg, G. Adv.
Synth. Catal. 2003, 345, 979. (c) Li, J.-H.; Li, J.-L.; Wang,
D.-P.; Pi, S.-F.; Xie, Y.-X.; Zhang, M.-B.; Hu, X.-C. J. Org.
Chem. 2007, 72, in press (DOI: 10.1021/jo0623742).
1
,1-Diphenylethene (20)16
1
H NMR (400 MHz, CDCl ): d = 7.35–7.30 (m, 10 H), 5.45 (s, 2 H).
3
1
3
C NMR (100 MHz, CDCl ): d = 150.0, 141.5, 128.2, 128.1, 127.7,
3
1
14.3.
+
LRMS (EI, 70 eV): m/z (%) = 180 (M , 100).
(
5) For papers on the other cross-coupling reaction catalyzed by
a catalytic amount of copper, see: (Sonogashira reaction)
(
a) Okuro, K.; Furuune, M.; Enna, M.; Miura, M.; Nomura,
Acknowledgment
M. J. Org. Chem. 1993, 58, 4716. (b) Gujadhur, R. K.;
Bates, C. G.; Venkataraman, D. Org. Lett. 2001, 3, 4315.
The authors thank Hunan Provincial Natural Science Foundation of
China (No. 05JJ1002), Fok Ying Dong Education Foundation (No.
(
c) Thathagar, M. B.; Beckers, J.; Rothenberg, G. Green
Chem. 2004, 6, 215. (d) Ma, D.; Liu, F. Chem. Commun.
004, 1934. (e) Wang, Y. F.; Deng, W.; Liu, L.; Guo, Q. X.
Chin. Chem. Lett. 2005, 16, 1197; Chem. Abstr. 2005, 144,
2662. (f) Saejueng, P.; Bates, C. G.; Venkataraman, D.
1
2
01012), the Key Project of Chinese Ministry of Education (No.
06102), Scientific Research Fund of Hunan Provincial Education
2
Department (No. 05B038) and the National Natural Science Foun-
dation of China (No. 20572020) for financial support.
2
Synthesis 2005, 1706. (g) Xie, Y.-X.; Deng, C.-L.; Pi, S.-F.;
Li, J.-H.; Yin, D.-L. Chin. J. Chem. 2006, 24, 1290. (Stille
reaction) (h) Kang, S.-K.; Kim, J.-S.; Choi, S.-C. J. Org.
Chem. 1997, 62, 4208. (i) Wang, Y.; Burton, D. J. Org. Lett.
References
(
1) For reviews, see: (a) Bringmann, G.; Walter, R.; Weirich, R.
Angew. Chem., Int. Ed. Engl. 1990, 29, 977. (b) Miyaura,
N.; Suzuki, A. Chem. Rev. 1995, 95, 2457. (c) Diederich,
F.; Stang, P. J. Metal-Catalyzed Cross-Coupling Reactions;
Wiley-VCH: Weinheim, 1998. (d) Miyaura, N. Cross-
Coupling Reaction; Springer: Berlin, 2002. (e) Negishi, E.
Handbook of Organopalladium Chemistry for Organic
Synthesis; Wiley-Interscience: New York, 2002. (f) Yong,
B. S.; Nolan, S. P. Chemtracts: Org. Chem. 2003, 205.
2
006, 8, 1109. (j) Mohapatra, S.; Bandyopadhyay, A.;
Barma, D. K.; Capdevila, J. H.; Falck, J. R. Org. Lett. 2003,
, 4759. (k) Kang, S.-K.; Yamaguchi, T.; Kim, T.-H.; Ho,
5
P.-S. J. Org. Chem. 1996, 61, 9082. (l) Li, J.-H.; Tang, B.-
X.; Tao, L.-M.; Liang, Y.; Zhang, M.-B. J. Org. Chem. 2006,
71, 7488.
(
(
6) For a paper on the use of the CuI/DABCO catalytic system
for Heck reaction, see: Li, J.-H.; Wang, D.-P.; Xie, Y.-X.
Tetrahedron Lett. 2005, 46, 4941.
7) For a preliminary communication, see: Li, J.-H.; Wang, D.-
P. Eur. J. Org. Chem. 2006, 2063.
8) Stephens, R. D.; Castro, C. E. J. Org. Chem. 1963, 28, 2163.
9) For the representative papers on TBAB-promoted
palladium-catalyzed Suzuki–Miyaura cross-coupling
reactions, see: (a) Reetz, M. T.; de Vries, J. G. Chem.
Commun. 2004, 1559; and references cited therein. (b) Liu,
W.-J.; Xie, Y.-X.; Liang, Y.; Li, J.-H. Synthesis 2006, 860.
(
g) Tang, S.; Liang, Y.; Liu, W.-J.; Li, J.-H. Chin. J. Org.
Chem. 2004, 24, 1133; Chem. Abstr. 2005, 142, 93160.
h) de Meijere, A.; Diederich, F. Metal-Catalyzed Cross-
Coupling Reactions; Wiley-VCH: Weinheim, 2004.
i) Phan, N. T. S.; van der Sluys, M.; Jone, C. P. Adv. Synth.
(
(
(
(
Catal. 2006, 348, 609.
(
2) For special reviews on copper-catalyzed cross-couplings,
see: (a) Siemsen, P.; Livingston, R. C.; Diederich, F. Angew.
Chem. Int. Ed. 2000, 39, 2632. (b) Hassan, J.; Sevignon,
M.; Gozzi, C.; Schulz, E.; Lemaire, M. Chem. Rev. 2002,
(
c) Bedford, R. B.; Blake, M. E.; Butts, C. P.; Holder, D.
Chem. Commun. 2003, 466.
102, 1359. (c) Ley, S. V.; Thomas, A. W. Angew. Chem. Int.
(
(
10) Venkatraman, S.; Li, C.-J. Org. Lett. 1999, 1, 1133.
11) Littke, A. F.; Dai, C.; Fu, G. C. J. Am. Chem. Soc. 2000, 122,
Ed. 2003, 42, 5400. (d) Beletskaya, I. P.; Cheprakov, A. V.
Coord. Chem. Rev. 2004, 248, 2337.
3) For representative papers on the nickel-catalyzed Suzuki–
Miyaura cross-coupling reaction, see: (a) Saito, S.; Ohtani,
S.; Miyaura, N. J. Org. Chem. 1997, 62, 8024. (b) Zim, D.;
Lando, V. R.; Dupond, J.; Monteiro, A. L. Org. Lett. 2001,
4020.
(
(
(
12) Pridgen, L. N.; Jones, S. S. J. Org. Chem. 1982, 47, 1590.
13) Wynberg, H.; van Driel, H. J. Am. Chem. Soc. 1965, 87,
3998.
(
(
14) Molander, G. A.; Biolatto, B. J. Org. Chem. 2003, 68, 4302.
15) Akiyama, R.; Kobayashi, S. Angew. Chem. Int. Ed. 2001, 40,
3, 3049. (c) Percec, V.; Golding, G. M.; Smidrkal, J.;
Weichold, O. J. Org. Chem. 2004, 69, 3447.
3
469.
16) Zeni, G.; Braga, A. L.; Stefani, H. A. Acc. Chem. Res. 2003,
6, 731; and references cited therein.
(
3
Synthesis 2007, No. 7, 984–988 © Thieme Stuttgart · New York