The first heterogeneous carbonylative Stille coupling of organostannanes with aryl iodides catalyzed by MCM-41-supported bidentate phosphine palladium(0) complex

Article abstract of DOI:10.1039/b914844m

The first heterogeneous carbonylative Stille coupling reaction of organostannanes with aryl iodides under an atmospheric pressure of carbon monoxide has been achieved in DMF at 80 °C in the presence of a catalytic amount of an MCM-41-supported bidentate phosphine palladium(0) complex [MCM-41-2P-Pd(0)], yielding a variety of unsymmetrical ketones in good to high yields. This polymeric palladium catalyst exhibited higher activity and selectivity than PdCl₂(PPh₃)₂ and can be recovered and recycled by a simple filtration of the reaction solution and used for at least 10 consecutive trials without any decrease in activity. Our system not only avoids the use of carbon monoxide under pressure, but also solves the basic problem of palladium catalyst recovery and reuse. The Royal Society of Chemistry 2009.

Full text of DOI:10.1039/b914844m

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The first heterogeneous carbonylative Stille coupling of organostannanes
with aryl iodides catalyzed by MCM-41-supported bidentate phosphine
palladium(0) complex
Mingzhong Cai,* Guomin Zheng and Guodong Ding
Received 24th May 2009, Accepted 22nd July 2009
First published as an Advance Article on the web 19th August 2009
DOI: 10.1039/b914844m
The first heterogeneous carbonylative Stille coupling reaction of organostannanes with aryl
iodides under an atmospheric pressure of carbon monoxide has been achieved in DMF at 80 ◦C in
the presence of a catalytic amount of an MCM-41-supported bidentate phosphine palladium(0)
complex [MCM-41-2P-Pd(0)], yielding a variety of unsymmetrical ketones in good to high yields.
This polymeric palladium catalyst exhibited higher activity and selectivity than PdCl2(PPh3)2 and
can be recovered and recycled by a simple filtration of the reaction solution and used for at least
10 consecutive trials without any decrease in activity. Our system not only avoids the use of carbon
monoxide under pressure, but also solves the basic problem of palladium catalyst recovery and
reuse.
in unacceptable palladium contamination of the product. The
high costs of the transition metal catalysts coupled with toxic
effects associated with many transition metals has led to an
Introduction
Aryl ketones,1 a,b-acetylenic ketones,2 and a,b-vinylic ketones3
are important building blocks for a large number of natural
increased interest in immobilizing catalysts onto a support. This
products and pharmaceutical compounds. One general ap-
class of supported reagents can facilitate both the isolation and
proach for the synthesis of aryl ketones is the Friedel–Crafts
recycling of the catalysts by simple filtration, thus providing an
acylation of substituted aromatic rings.4 The crucial disadvan-
environmentally cleaner process.13 So far, polymer-supported
tage of traditional Friedel–Crafts acylation is the use of more
palladium catalysts have successfully been used for the Heck
than a stoichiometric amount of aluminium trichloride, which is
reaction,14 the Suzuki reaction,15 the Sonogashira reaction,16 and
incompatible with many functional groups and generates a large
amount of waste. A common route to a,b-acetylenic ketones
involves the acylation of alkynyl organometallic reagents, such
as silver,5 copper,6 lithium,7 zinc,8 silicon,9 and tin10 with acid
the Stille reaction,17 etc. However, to the best of our knowledge,
there has been no general study of carbonylative Stille cross-
coupling reaction catalyzed by a polymer-supported palladium
complex described to date.
chlorides. One of the most common methods for preparation of
Recent developments on the mesoporous material MCM-
a,b-vinylic ketones is based on the Horner–Emmons reaction
41 provided a new possible candidate for a solid support for
using b-oxophophonates and carbonyl compounds.11 Generally,
the preparation of unsymmetrical ketones by transition-metal-
catalyzed cross-coupling reaction is severely limited, since the
organometallic partners often react with the product ketone.
The palladium-catalyzed carbonylative cross-coupling of aryl
and vinyl halides or triflates with organostannanes in the
presence of carbon monoxide is an especially valuable synthetic
procedure for the preparation of a variety of aryl, vinylic,
and acetylenic ketones, since a wide variety of functionalities
can be tolerated on either partner and the organotin reagents
can be readily synthesized, purified, and stored.12 However,
the carbonylative Stille cross-coupling reaction generally pro-
ceeds in the presence of a homogeneous palladium catalyst
such as Pd(PPh3)4, PdCl2(PPh3)2, PdCl2(dppf), Pd(dba)2/2PPh3,
PhPdI(PPh3)2, and PhCH2PdCl(PPh3)2, which makes the re-
covery of the metal tedious if not impossible and might result
immobilization of homogeneous catalysts.18 MCM-41 has a
regular pore diameter of ca. 5 nm and a specific surface area
> 700 m2 g-1.19 Its large pore size allows passage of large
molecules such as organic reactants and metal complexes
through the pores to reach to the surface of the channel.20 It
is generally believed that high surface area of heterogeneous
catalyst results in high catalytic activity. Considering the fact
that MCM-41 support has an extremely high surface area
and the catalytic palladium species is anchored on the inner
surface of the mesopores of the MCM-41 support, we expect
that MCM-41-supported palladium catalyst will exhibit high
activity and good reusability. To date, a few palladium complexes
on functionalized MCM-41 support have been prepared and
successfully used in organic reactions.21 Recently, we have
reported the synthesis of the MCM-41-supported bidentate
phosphine palladium(0) complex [abbreviated as MCM-41-2P-
Pd(0)] and found that this complex is a highly active and
recyclable catalyst for the Sonogashira reaction of aryl halides.16e
In this paper, we wish to report that the carbonylative Stille
coupling reaction of organostannanes with aryl iodides under an
Department of Chemistry, Jiangxi Normal University, Nanchang,
330022, P.R. China. E-mail: caimzhong@163.com;
Fax: (+86)-791-812-0388
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atmospheric pressure of carbon monoxide can be easily achieved
in the presence of a catalytic amount of MCM-41-supported
bidentate phosphine palladium(0) complex [MCM-41-2P-Pd(0)]
to yield the corresponding aryl ketones, a,b-acetylenic ketones,
and a,b-vinylic ketones in good to high yields. The developed
methodology has important practical advantages deserving
special note.
were conducted in DMF, NMP and HMPA, high yields of
carbonylative coupling products A were isolated. Use of THF,
CH3CN and toluene as solvents led to slower reactions and
the direct coupling products B were formed in 19–23% yields
(entries 7–9). Increasing the amount of palladium catalyst could
shorten the reaction time, but did not increase the yield of
carbonylative coupling product A (entry 10). The low palladium
concentration usually led to a long period of reaction, which was
consistent with our experimental result (entry 11). Thus, the
optimized reaction conditions for this carbonylative coupling
reaction are the MCM-41-2P-Pd(0) (1 mol%) in DMF at 80 ◦C
under atmospheric pressure of carbon monoxide for 6 h.
Results and discussion
The MCM-41-supported bidentate phosphine palladium(0)
complex [MCM-41-2P-Pd(0)] was prepared by our previous
procedure.16e The phosphine and palladium content was 1.15
and 0.52 mmol g-1, respectively. Tanaka reported that car-
bonylative coupling reactions of aryl iodides with organos-
tannanes catalyzed by PhPdI(PPh3)2 in HMPA required high
temperature (120 ◦C) and high pressure of carbon monoxide
(30 atm).22 In our initial screening experiments, the real-
ization of a carbonylative Stille coupling reaction catalyzed
by the MCM-41-2P-Pd(0) under an atmospheric pressure of
carbon monoxide was our goal. When we searched for a
carbonylative coupling protocol for use with iodobenzene and
(4-methylphenyl)tributylstannane, we observed that iodoben-
zene could react with (4-methylphenyl)tributylstannane in the
presence of 1 mol% of the MCM-41-2P-Pd(0) in DMF under
an atmospheric pressure of carbon monoxide at 60 ◦C to
afford the desired carbonylative coupling product in 62%
yield. Encouraged by this result, we continued our search to
improve the yield of the product by optimization of the reaction
conditions (Table 1).
We have investigated the reactions using a variety of organos-
tannanes and a wide range of aryl iodides as the substrates under
the optimized reaction conditions (Scheme 1) and the results are
outlined in Table 2. As shown in Table 2, the carbonylative
Stille coupling reaction of arylstannanes with a variety of aryl
iodides proceeded smoothly under mild conditions to give the
corresponding carbonylative coupling products 3a–f in good
to high yields (entries 1–6). The presence of a strong electron-
withdrawing substituent such as NO2 is known to promote
the direct coupling reaction to produce biaryl. For example,
the carbonylative coupling reaction of triphenylalane with
4-iodonitrobenzene was reported to provide a 41% yield of 4-
nitrobenzophenone and a 55% yield of 4-nitrobiphenyl,23 and an
analogous reaction with tributyltin hydride resulted in only a 9%
yield of 4-nitrobenzaldehyde with an accompanying 84% yield
of nitrobenzene.24 This polymeric palladium catalyst exhibits
higher activity and selectivity than PdCl2(PPh3)2. For example,
the carbonylative coupling reaction of 4-iodonitrobenzene with
(4-methylphenyl)tributylstannane in the presence of 1 mol% of
MCM-41-2P-Pd(0) in DMF at 80 ◦C for 6 h gave a 90% yield of
the carbonylative coupling product 3b along with only 2% yield
of 4-methyl-4¢-nitrobiphenyl (entry 2), the same reaction in the
We tested several different temperatures for the carbonylative
coupling reaction catalyzed by MCM-41-2P-Pd(0) in DMF.
80 ◦C was found to be the most effective. Other temperatures
such as 60 and 100 ◦C were substantially less effective, and
no carbonylative coupling reaction occurred at 25 ◦C (entry
1). We then turned our attention to investigate the effect of
solvents on the carbonylative coupling reaction. The solvents
affected the selectivity of the reaction. When the reactions
◦
presence of 1 mol% of PdCl2(PPh3)2 in DMF at 80 C for 6 h
gave 3b in 79% yield and 4-methyl-4¢-nitrobiphenyl in 12% yield.
The carbonylative coupling reaction of the sterically hindered
1-iodonaphthalene with (4-chlorophenyl)tributylstannane also
proceeded to afford the corresponding carbonylative coupling
product 3f in good yield (entry 6). The reactions of tetram-
ethylstannane with aryl iodides at 70 ◦C gave the corresponding
methyl aryl ketones 3g and 3h in high yields (entries 7 and 8).
The carbonylative coupling reaction of heteroaryl iodides such
as 2-iodothiophene with tetramethylstannane at 70 ◦C afforded
the corresponding methyl heteroaryl ketone 3i in 75% yield
(entry 9).
Table 1 Carbonylative Stille cross-coupling of (4-methylphenyl)-
tributylstannane with iodobenzene under different conditionsa
Yield (%)b
Catalyst
amount
Entry
Solvent
Temp./◦C Time/h
A
B
1
2
3
4
5
6
7
8
9
DMF
DMF
DMF
DMF
NMP
HMPA
THF
Toluene 1 mol%
CH3CN 1 mol%
DMF
DMF
1 mol%
1 mol%
1 mol%
1 mol%
1 mol%
1 mol%
1 mol%
25
60
80
100
80
80
60
80
80
80
80
24
24
6
4
6
0
17
13
4
7
6
62
86
84
85
83
43
51
42
86
85
6
7
24
24
24
4
19
23
20
5
10
11
2 mol%
0.5 mol%
14
4
a Iodobenzene
(1.00
mmol),
(4-methylphenyl)tributylstannane
(1.10 mmol), CO (1 atm), and solvent (3 mL). b Isolated yields.
Scheme 1 Synthesis of unsymmetrical ketones.
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Table 2 Synthesis of unsymmetrical ketonesa
R1
reaction of iodobenzene with (4-methylphenyl)tributylstannane.
We filtered off the MCM-41-2P-Pd(0) complex after a reaction
time of 1 h and allowed the filtrate to react further. The catalyst
filtration was performed at the reaction temperature (80 ◦C)
in order to avoid possible recoordination or precipitation of
soluble palladium upon cooling. We found that, after this hot
filtration, no further reaction was observed. This result suggests
that the palladium catalyst remains on the support at elevated
temperatures during the reaction.
The heterogeneous carbonylative Stille cross-coupling of
organostannanes with aryl iodide may proceed through a
catalytic cycle analogous to that proposed for homogeneous pal-
ladium catalysts (cycle A in Scheme 2).12b,22 Oxidative addition
of ArI (1) to the MCM-41-2P-Pd(0) complex provides MCM-
41-bound arylpalladium(II) complex (5), which is followed by
migratory insertion of carbon monoxide giving MCM-41-bound
acylpalladium(II) complex (6). Subsequent transmetalation be-
tween 6 and organostannanes (2) and reductive elimination of
unsymmetrical ketone 3 from the intermediate (7) regenerate the
MCM-41-2P-Pd(0) complex. Since 5 is a common intermediate
for the carbonylation (cycle A) and the direct coupling giving
biaryls (cycle B), a large amount of biaryl (4) is often formed
when the insertion reaction of carbon monoxide into the
intermediate (5) is slower than the transmetalation between 5
and organostannanes (2).
Entry Ar
R
Product Yield (%)b
1
2
3
4
5
6
7
8
9
Ph
n-Bu 4-CH3C6H4
3a
3b
3c
3d
3e
3f
86
90
88
85
87
80
84c
86c
75c
81
86
83
80
84
85
79d
85d
84
78
82
88
86
72
89
85
90
84
4-O2NC6H4 n-Bu 4-CH3C6H4
4-CH3OC6H4 n-Bu 4-CH3C6H4
4-BrC6H4
4-H2NC6H4 n-Bu 4-ClC6H4
1-naphthyl n-Bu 4-ClC6H4
4-O2NC6H4 Me
4-CH3OC6H4 Me
2-thienyl
n-Bu 4-ClC6H4
Me
Me
Me
3g
3h
3i
3j
3k
3l
Me
≡
≡
≡
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
4-O2NC6H4 n-Bu C4H9C
C
C
C
4-CH3C6H4
n-Bu C4H9C
4-CH3OC6H4 n-Bu C4H9C
≡
Ph
4-BrC6H4
4-CH3OC6H4 n-Bu PhC
n-Bu PhC
n-Bu PhC
C
3m
3n
3o
≡
≡
C
C
=
4-O2NC6H4 n-Bu (Z)-C4H9CH CH 3p
=
4-O2NC6H4 n-Bu (Z)-PhCH CH
3q
=
4-O2NC6H4 n-Bu (E)-C4H9CH CH 3p
=
2-CH3OC6H4 n-Bu (E)-C4H9CH CH 3r
=
2-thienyl
4-ClC6H4
n-Bu (E)-C4H9CH CH 3s
n-Bu (E)-PhCH CH
=
3t
=
4-CH3OC6H4 n-Bu (E)-PhCH CH
3u
3v
3w
3x
3y
3z
=
2-CF3C6H4
Ph
n-Bu (E)-PhCH CH
n-Bu CH2 CH
=
=
3-O2NC6H4 n-Bu CH2 CH
=
4-CH3C6H4
1-naphthyl
n-Bu CH2 CH
n-Bu CH2 CH
=
a Reaction was carried out with organostannane (1.10 mmol), aryl iodide
(1.00 mmol), CO (1 atm), and 1 mol% palladium catalyst in DMF (3 mL)
at 80 ◦C for 6 h. b Isolated yields. c At 70 ◦C for 10 h. d Only (E)-isomer
was obtained.
The carbonylative Stille cross-coupling of alkynylstannanes
and vinylstannanes with a variety of aryl iodides also proceeded
smoothly under the same conditions to give the corresponding
a,b-acetylenic ketones 3j–3o (entries 10–15) and a,b-vinylic
ketones 3p–3z (entries 16–27) in good to high yields, respectively.
It was found that the (E)-configuration of the double bond
in vinylstannanes was retained in the products (entries 18–
23); however, the (Z)-configuration of the double bond in
vinylstannanes was lost completely under the reaction condi-
tions and only the (E)-isomer of the product was obtained
(entries 16 and 17). A similar observation has been made by
Stille et al. in carbonylative cross-coupling of vinyl iodides and
vinylstannanes.12b The method provides a quite general route for
synthesis of a variety of unsymmetrical ketones having various
functionalities such as alkynyl, vinyl, halogen, NO2, CH3O,
NH2, CH3, etc. The results above prompted us to investigate
the reaction of aryl bromides, but the carbonylative coupling
reaction was very slow under the conditions optimized for the
iodides. Even though the carbonylative coupling reactions of
aryl bromides were carried out in DMF at 100 or 120 ◦C,
only traces of carbonylative coupling products were formed.
On the other hand, the carbonylative coupling reaction of
4-bromoiodobenzene selectively occurred at the C–I bond, no
diketones was formed (entries 4 and 14).
Scheme 2 Catalytic cycle.
The MCM-41-2P-Pd(0) complex catalyst can be easily recov-
ered by simple filtration. We also investigated the possibility to
reuse the catalyst by using the carbonylative coupling reaction of
4-iodoanisole with (4-methylphenyl)tributylstannane and the re-
sults are given in Table 3. In general, the continuous recycling of
resin-supported palladium catalysts is difficult owing to leaching
of the palladium species from the polymer supports, which often
reduces their activity within five recycles. However, when the re-
action of 4-iodoanisole with (4-methylphenyl)tributylstannane
was performed even with 1 mol% of MCM-41-2P-Pd(0), the
catalyst could be recycled 10 times without any loss of activity.
The reaction promoted by the 10th recycled catalyst gave 3c
in 86% yield (entry 2). The average yield of 3c in consecutive
reactions promoted by the 1st through the 10th recycled catalyst
was 87% (entry 3). The high stability and excellent reusability
of the catalyst result from the chelating action of the bidentate
phosphine ligand on palladium and the mesoporous structure of
the MCM-41 support. The result is important from a practical
point of view. The high catalytic activity, excellent reusability
and the easy accessibility of the MCM-41-2P-Pd(0) complex
In order to determine whether the catalysis was due to the
MCM-41-2P-Pd(0) complex or to a homogeneous palladium
complex that comes off the support during the reaction and
then returns to the support at the end, we performed the
hot filtration test.25 We focused on the carbonylative coupling
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Table 3 Carbonylative Stille cross-coupling reaction of 4-iodoanisole
with (4-methylphenyl)tributylstannane catalyzed by recycled catalyst
under reduced pressure. The residue was purified by flash column
chromatography on silica gel (hexane–ethyl acetate = 10 : 1).
The recyclability of the MCM-41-2P-Pd(0)
After carrying out the reaction, the mixture was vacuum filtered
using a sintered glass funnel and the residue was washed with
diethyl ether (2 ¥ 5 mL), DMF (2 ¥ 5 mL), ethanol (2 ¥ 5 mL),
and diethyl ether (2 ¥ 5 mL), respectively. After being dried
in an oven, the catalyst can be reused directly without further
purification.
4-Methylbenzophenone 3a. White solid, m.p. 56–57 ◦C, lit.26
◦
1
m.p. 57–58 C. H NMR (400 MHz, CDCl3) d 7.78 (m, 2 H),
7.72 (d, J = 8.0 Hz, 2 H), 7.56 (m, 1 H), 7.46 (m, 2 H), 7.26 (m,
2 H), 2.43 (s, 3 H). 13C NMR (100 MHz, CDCl3) d 196.5, 143.3,
138.0, 134.9, 132.2, 130.3, 130.0, 129.0, 128.2, 21.7. IR (KBr) n
(cm-1) 1657, 1606, 1578, 1277, 700.
Entry Catalyst cycle
Isolated yield (%)
TON
4-◦Methyl-4¢-nitrobenzoph◦enone 3b. Yellow solid, m.p. 120–
1
2
3
1st
10th
88
86
av. 87
88
86
1
122 C, lit.27 m.p. 120–121 C. H NMR (400 MHz, CDCl3) d
1st to 10th consecutive
total of 870
8.33 (m, 2 H), 7.92 (m, 2 H), 7.71 (d, J = 8.4 Hz, 2 H), 7.32 (d,
J = 8.0 Hz, 2 H), 2.47 (s, 3 H). 13C NMR (100 MHz, CDCl3)
d 194.5, 149.7, 144.6, 143.3, 133.6, 130.6, 130.3, 129.4, 123.5,
21.8. IR (KBr) n (cm-1) 1652, 1600, 1520, 1353, 1315, 732.
make them a highly attractive supported palladium catalyst
for the parallel solution phase synthesis of diverse libraries of
compounds.
4-Methoxy-4¢-methyl◦benzophenone 3c. White solid, m.p. 88–
89 ◦C, lit.28 m.p. 85–87 C. 1H NMR (400 MHz, CDCl3) d 7.82
(m, 2 H), 7.69 (d, J = 8.0 Hz, 2 H), 7.28 (d, J = 8.4 Hz, 2 H),
6.97 (m, 2 H), 3.90 (s, 3 H), 2.45 (s, 3 H). 13C NMR (100 MHz,
CDCl3) d 195.4, 163.0, 142.6, 135.5, 132.5, 130.5, 130.0, 128.9,
113.5, 55.5, 21.6. IR (KBr) n (cm-1) 1646, 1598, 1505, 1262, 1170,
849, 761.
Experimental
Aryl iodides, tetramethyltin, and ethenyltributylstannane were
reagent grade and used as purchased. Arylstannanes, alkynyl-
stannanes, and vinylstannanes were prepared according to the
literature method.12e All the solvents were dried and distilled be-
fore use. The products were purified by flash chromatography on
silica gel. A mixture of EtOAc and hexane was generally used as
eluent. All carbonylative coupling products were characterized
by comparison of their spectra and physical data with authentic
samples. IR spectra were determined on a Perkin-Elmer 683
4-◦Bromo-4¢-chlorobenzophenone 3d. White solid, m.p. 146–
◦
1
148 C, lit.29 m.p. 147–148 C. H NMR (400 MHz, CDCl3) d
7.73 (d, J = 8.4 Hz, 2 H), 7.64 (s, 4 H), 7.47 (d, J = 8.8 Hz,
2 H). 13C NMR (100 MHz, CDCl3) d 194.4, 139.2, 136.0, 135.5,
131.8, 131.4, 131.3, 128.8, 127.8. IR (KBr) n (cm-1) 1646, 1586,
1289, 855, 753.
1
instrument. H NMR spectra were recorded on a Bruker AC-
P400 (400 MHz) spectrometer with TMS as an internal standard
inCDCl3 as solvent. 13C NMRspectrawere recordedonaBruker
AC-P400 (100 MHz) spectrometer in CDCl3 as solvent. Mass
spectra (EI, 70 eV) were determined on a Finnigan 8230 mass
spectrometer. Melting points are uncorrected. Microanalyses
were measured by using a Yanaco MT-3 CHN microelemental
analyzer.
4-◦Amino-4¢-chlorobenzophenone 3e. White solid, m.p. 183–
◦
1
184 C, lit.30 m.p. 182–184 C. H NMR (400 MHz, CDCl3) d
7.70–7.66 (m, 4 H), 7.44 (m, 2 H), 6.68 (m, 2 H), 4.18 (br, 2 H).
13C NMR (100 MHz, CDCl3) d 194.0, 151.1, 137.7, 137.1, 132.9,
131.0, 128.4, 127.1, 113.7. IR (KBr) n (cm-1) 3342, 3228, 1639,
1630, 1587, 1320, 928, 836, 766.
1-(4-Chlorobenzoyl)naphthalene 3f28. Oil. 1H NMR
(400 MHz, CDCl3) d 8.12–7.91 (m, 3 H), 7.81 (m, 2 H),
7.57–7.41 (m, 6 H). 13C NMR (100 MHz, CDCl3) d 196.6,
139.7, 136.7, 135.9, 133.8, 131.8, 131.6, 130.9, 128.8, 128.5,
127.8, 127.5, 126.6, 125.6, 124.4. IR (neat) n (cm-1) 1661, 1586,
1508, 1284, 1251, 800, 778.
Typical procedure for the carbonylative Stille cross-coupling
reaction
A 50 mL round-bottomed flask equipped with a gas inlet tube,
a reflux condenser, and a magnetic stirring bar was charged
with MCM-41-2P-Pd(0) (20 mg, 0.01 mmol Pd), aryl iodide
(1.0 mmol), and organostannanes (1.1 mmol). The flask was
flushed with carbon monoxide, and DMF (3 mL) was then
added. After stirring at 80 ◦C for 6 h under CO (1 atm),
the reaction mixture was cooled to room temperature, diluted
with diethyl ether (30 mL). The mixture was vacuum filtered
using a sintered glass funnel and washed with diethyl ether
(2 ¥ 5 mL). The ether solution was washed with water (3 ¥
10 mL) and dried over anhydrous MgSO4 and concentrated
◦
4-Acetyln◦itrobenzene 3g. Yellow solid, m.p. 76–78 C, lit.31
1
m.p. 78–80 C. H NMR (400 MHz, CDCl3) d 8.32 (m, 2 H),
8.12 (m, 2 H), 2.69 (s, 3 H). 13C NMR (100 MHz, CDCl3) d
196.3, 150.4, 141.4, 129.3, 123.9, 27.0. IR (KBr) n (cm-1) 1694,
1608, 1527, 1346, 857, 750.
1
4-Acetylanisole 3h31. Oil. H NMR (400 MHz, CDCl3) d
7.94 (m, 2 H), 6.93 (m, 2 H), 3.87 (s, 3 H), 2.56 (s, 3 H). 13C
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NMR (100 MHz, CDCl3) d 196.8, 163.5, 130.6, 130.4, 113.7,
55.5, 26.3. IR (neat) n (cm-1) 1668, 1606, 1577, 1509, 1261, 1179,
837.
(61), 204 (93), 202 (97), 150 (100). Anal. Calcd for C13H15NO3:
C, 66.94; H, 6.48. Found: C, 66.69; H, 6.30.
(E)-1-(4-Nitropheny◦ l)-3-phenylprop-2-en-1-one 3q. Yellow
2-Acetylthiophene 3i32. Oil. 1H NMR (400 MHz, CDCl3) d
7.70 (m, 1 H), 7.64 (m, 1 H), 7.13 (m, 1 H), 2.57 (s, 3 H). 13C
NMR (100 MHz, CDCl3) d 190.7, 144.6, 133.8, 132.4, 128.1,
26.9. IR (neat) n (cm-1) 1652, 1518, 1416, 1275, 858, 726.
1
solid, m.p. 145–146 C. H NMR (400 MHz, CDCl3) d 8.36
(d, J = 8.0 Hz, 2 H), 8.15 (d, J = 8.0 Hz, 2 H), 7.85 (d, J =
15.6 Hz, 1 H), 7.67 (m, 2 H), 7.51–7.45 (m, 4 H). 13C NMR
(100 MHz, CDCl3) d 189.1, 150.1, 146.9, 143.1, 134.3, 131.3,
129.4, 129.2, 128.7, 123.9, 121.3. IR (KBr) n (cm-1) 3053, 1663,
1591, 1516, 1335, 1208, 853, 742. MS (EI), m/z (%): 253 (M+,
74), 252 (100), 103 (42), 77 (31). Anal. Calcd for C15H11NO3: C,
71.14; H, 4.38. Found: C, 70.87; H, 4.19.
1-(4-Nitrophenyl)hept-2-yn-1-one 3j33. Oil. 1H NMR
(400 MHz, CDCl3) d 8.33 (d, J = 9.2 Hz, 2 H), 8.29 (d, J =
9.2 Hz, 2 H), 2.56 (t, J = 7.2 Hz, 2 H), 1.70 (m, 2 H), 1.52 (m,
2 H), 0.98 (t, J = 7.2 Hz, 3 H). 13C NMR (100 MHz, CDCl3)
d 176.0, 150.8, 141.1, 130.4, 123.7, 99.4, 79.4, 29.7, 22.1, 19.0,
13.5. IR (neat) n (cm-1) 2953, 2872, 2205, 1643, 1603, 1527,
1343, 1268, 865, 707.
1
(E)-1-(2-Methoxyphenyl)hept-2-en-1-one 3r. Oil. H NMR
(400 MHz, CDCl3) d 7.49 (m, 1 H), 7.42 (m, 1 H), 7.01–6.94
(m, 2 H), 6.82 (dt, J = 15.6, 6.8 Hz, 1 H), 6.66 (d, J = 15.6 Hz,
1 H), 3.85 (s, 3 H), 2.26 (m, 2 H), 1.47 (m, 2 H), 1.36 (m, 2 H),
0.92 (t, J = 7.2 Hz, 3 H). 13C NMR (100 MHz, CDCl3) d 193.7,
157.8, 149.0, 132.3, 130.7, 130.0, 129.4, 120.6, 111.6, 55.6, 32.2,
30.2, 22.2, 13.8. IR (neat) n (cm-1) 2931, 2872, 1663, 1618, 1465,
1245, 1024, 981. MS (EI), m/z (%): 218 (M+, 51), 161 (99), 135
(100), 121 (58), 77 (61). Anal. Calcd for C14H18O2: C, 77.03; H,
8.31. Found: C, 76.75; H, 8.12.
1-(4-Methylphenyl)hept-2-yn-1-one 3k33. Oil. 1H NMR
(400 MHz, CDCl3) d 8.03 (d, J = 8.4 Hz, 2 H), 7.27 (d, J =
8.4 Hz, 2 H), 2.50 (t, J = 7.2 Hz, 2 H), 2.42 (s, 3 H), 1.66 (m, 2 H),
1.50 (m, 2 H), 0.96 (t, J = 7.2 Hz, 3 H). 13C NMR (100 MHz,
CDCl3) d 178.0, 144.9, 134.7, 129.7, 129.2, 96.3, 79.7, 29.9, 22.1,
21.8, 18.9, 13.5. IR (neat) n (cm-1) 3031, 2959, 2873, 2200, 1642,
1605, 1268, 911, 742.
(E)-1-(2-Thienyl)hept-2-en-1-one
3s. Oil.
1H
NMR
1-(4-Methoxyphenyl)hept-2-yn-1-one 3l33. Oil. 1H NMR
(400 MHz, CDCl3) d 8.10 (d, J = 9.2 Hz, 2 H), 6.94 (d, J =
9.2 Hz, 2 H), 3.88 (s, 3 H), 2.49 (t, J = 7.2 Hz, 2 H), 1.66 (m, 2 H),
1.50 (m, 2 H), 0.96 (t, J = 7.2 Hz, 3 H). 13C NMR (100 MHz,
CDCl3) d 176.9, 164.3, 131.9, 130.4, 113.7, 95.9, 79.7, 55.5, 29.9,
22.1, 18.9, 13.5. IR (neat) n (cm-1) 3075, 2959, 2873, 2201, 1639,
1598, 1257, 1166, 845, 759.
(400 MHz, CDCl3) d 7.76 (m, 1 H), 7.64 (m, 1 H), 7.15–
7.09 (m, 2 H), 6.79 (d, J = 15.6 Hz, 1 H), 2.31 (m, 2 H), 1.50
(m, 2 H), 1.38 (m, 2 H), 0.93 (t, J = 7.2 Hz, 3 H). 13C NMR
(100 MHz, CDCl3) d 182.4, 149.3, 145.2, 133.5, 131.7, 128.1,
125.4, 32.4, 30.3, 22.3, 13.8. IR (neat) n (cm-1) 2957, 2930, 1659,
1615, 1516, 1416, 1235, 979, 721. MS (EI), m/z (%): 194 (M+,
54), 165 (36), 111 (100). Anal. Calcd for C11H14OS: C, 68.00; H,
7.26. Found: C, 67.71; H, 7.38.
1◦,3-Diphenylprop-2-yn-1-one 3m. White solid, m.p. 45–
◦
1
46 C, lit.34 m.p. 46–47 C. H NMR (400 MHz, CDCl3) d
8.23 (d, J = 8.0 Hz, 2 H), 7.69 (d, J = 7.6 Hz, 2 H), 7.64 (t, J =
7.2 Hz, 1 H), 7.54–7.41 (m, 5 H). 13C NMR (100 MHz, CDCl3)
d 178.0, 136.9, 134.1, 133.1, 130.8, 129.6, 128.7, 128.6, 120.2,
93.1, 86.9. IR (KBr) n (cm-1) 3056, 2201, 1641, 1587, 760.
(E)-1-(4-Chloro◦phenyl)-3-phenylprop-2-en-1-one 3t. White
solid, m.p. 92–94 C, lit.35 m.p. 91–92 ◦C. 1H NMR (400 MHz,
CDCl3) d 7.97 (m, 2 H), 7.82 (d, J = 15.6 Hz, 1 H), 7.65 (m,
2 H), 7.51–7.42 (m, 6 H). 13C NMR (100 MHz, CDCl3) d 189.2,
145.4, 139.2, 136.5, 134.7, 130.8, 129.9, 129.0, 128.5, 121.6. IR
(KBr) n (cm-1) 3053, 1662, 1606, 1336, 983, 829, 764.
1-(4-Bromophenyl)-3-phenylprop-2-yn-1-one
3n. White
solid, m.p. 109–110 C, lit.34 m.p. 106–107 ◦C. 1H NMR
(400 MHz, CDCl3) d 8.09 (m, 2 H), 7.70–7.66 (m, 4 H),
7.53–7.42 (m, 3 H). 13C NMR (100 MHz, CDCl3) d 176.9,
135.7, 133.1, 132.0, 131.0, 130.9, 129.6, 128.8, 119.9, 93.7, 86.6.
IR (KBr) n (cm-1) 3058, 2199, 1651, 1585, 751, 682.
◦
(E)-1-(4-Methoxyphenyl)-3-phenylprop-2-en-1-one 3u. White
◦
solid, m.p. 102–103 C, lit.12e m.p. 105–106 ◦C. 1H NMR
(400 MHz, CDCl3) d 8.04 (m, 2 H), 7.80 (d, J = 15.6 Hz,
1 H), 7.65 (m, 2 H), 7.55 (d, J = 15.6 Hz, 1 H), 7.43–7.39 (m,
3 H), 6.98 (m, 2 H), 3.89 (s, 3 H). 13C NMR (100 MHz, CDCl3)
d 188.8, 163.5, 144.0, 135.1, 131.1, 130.8, 130.3, 128.9, 128.4,
121.9, 113.9, 55.5. IR (KBr) n (cm-1) 1655, 1607, 1574, 1338,
974, 830, 763.
1-(4-Methoxyphe◦nyl)-3-phenylprop-2-yn-1-one
3o. White
solid, m.p. 100–101 C, lit.34 m.p. 97–98 ◦C. 1H NMR (400 MHz,
CDCl3): d 8.20 (d, J = 8.8 Hz, 2 H), 7.67 (d, J = 7.6 Hz, 2 H),
7.49–7.39 (m, 3 H), 6.99 (d, J = 8.4 Hz, 2 H), 3.90 (s, 3 H). 13
C
(E)-1-(2-Trifluoromethylphenyl)-3-phenylprop-2-en-1-one 3v36.
NMR (100 MHz, CDCl3) d 176.7, 164.5, 133.0, 132.0, 130.6,
130.4, 128.7, 120.4, 113.9, 92.3, 87.0, 55.6. IR (KBr) n (cm-1)
2201, 1631, 1603, 1160, 761.
1
Oil. H NMR (400 MHz, CDCl3) d 7.76 (d, J = 8.0 Hz, 1 H),
7.61 (m, 2 H), 7.53–7.45 (m, 3 H), 7.41–7.36 (m, 3 H), 7.30 (d, J =
16.0 Hz, 1 H), 7.04 (d, J = 16.0 Hz, 1 H). 13C NMR (100 MHz,
CDCl3) d 195.1, 147.8, 138.9, 134.1, 131.6, 131.1, 129.9, 129.0,
128.6, 128.1, 126.8, 126.7 (q), 125.0, 122.3. IR (neat) n (cm-1)
1651, 1606, 1576, 1449, 1315, 1172, 979, 830, 769.
(E)-1-(4-Nitrophenyl)hept-2-en-1-one 3p. Oil. 1H NMR
(400 MHz, CDCl3) d 8.31 (m, 2 H), 8.04 (m, 2 H), 7.12 (dt,
J = 15.6, 7.2 Hz, 1 H), 6.84 (d, J = 15.6 Hz, 1 H), 2.36 (m, 2 H),
1.53 (m, 2 H), 1.40 (m, 2 H), 0.95 (t, J = 7.2 Hz, 3 H). 13C NMR
(100 MHz, CDCl3) d 189.4, 152.5, 150.0, 142.9, 129.4, 125.6,
123.7, 32.7, 30.2, 22.3, 13.8. IR (neat) n (cm-1) 2931, 2861, 1674,
1621, 1602, 1524, 1346, 983. MS (EI), m/z (%): 233 (M+, 73), 231
1-Phenylprop-2-en-1-one 3w37. Oil. 1H NMR (400 MHz,
CDCl3) d 7.95 (m, 2 H), 7.58 (m, 1 H), 7.48 (m, 2 H), 7.16
(m, 1 H), 6.43 (m, 1 H), 5.93 (m, 1 H). 13C NMR (100 MHz,
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CDCl3) d 191.1, 137.3, 133.0, 132.4, 130.2, 128.7, 128.6. IR
(neat) n (cm-1) 1674, 1609, 1580, 1233, 728, 690.
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◦
1
104–106 C. H NMR (400 MHz, CDCl3) d 8.77 (s, 1H), 8.45
(m, 1 H), 8.28 (m, 1 H), 7.71 (t, J = 8.0 Hz, 1 H), 7.18 (m, 1 H),
6.53 (m, 1 H), 6.08 (m, 1 H). 13C NMR (100 MHz, CDCl3) d
188.7, 148.5, 138.6, 134.2, 132.1, 131.5, 130.0, 127.3, 123.5. IR
(KBr) n (cm-1) 1666, 1601, 1537, 1351, 1237, 727. MS (EI), m/z
(%): 177 (M+, 24), 150 (97), 104 (74), 76 (100), 55 (68). Anal.
Calcd for C9H7NO3: C, 61.02; H, 3.98. Found: C, 60.74; H, 3.73.
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1-(4-Methylphenyl)prop-2-en-1-one 3y38. Oil. 1H NMR
(400 MHz, CDCl3) d 7.86 (m, 2 H), 7.28 (d, J = 8.0 Hz, 2 H),
7.16 (m, 1 H), 6.43 (m, 1 H), 5.90 (m, 1 H), 2.42 (s, 3 H). 13C
NMR (100 MHz, CDCl3) d 190.5, 143.9, 134.8, 132.4, 129.7,
129.3, 128.9, 21.7. IR (neat) n (cm-1) 1673, 1608, 1579, 1234,
742.
1-(1-Naphthyl)prop-2-en-1-one 3z12e
.
Oil. 1H NMR
(400 MHz, CDCl3) d 8.33 (d, J = 8.0 Hz, 1 H), 7.98 (d,
J = 8.0 Hz, 1 H), 7.89 (m, 1 H), 7.72 (m, 1 H), 7.58–7.48 (m,
3 H), 6.95 (m, 1 H), 6.26 (m, 1 H), 6.04 (m, 1 H). 13C NMR
(100 MHz, CDCl3) d 195.9, 137.0, 135.8, 133.9, 132.0, 131.3,
130.6, 128.4, 127.8, 127.5, 126.5, 125.6, 124.3. IR (neat) n (cm-1)
3049, 1667, 1603, 1508, 1102, 785.
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Conclusions
In summary, we have developed a novel, efficient, practical
and green catalyst system for the carbonylative Stille coupling
reaction of organostannanes with aryl iodides by using the
MCM-41-supported bidentate phosphine palladium(0) complex
as catalyst in DMF under an atmospheric pressure of carbon
monoxide. The carbonylative coupling reaction of organostan-
nanes with aryl iodides generates a variety of unsymmetrical
ketones having various functionalities in good to high yields
under the present reaction conditions. Our system not only
avoids the use of carbon monoxide under pressure, but also
solves the basic problem of palladium catalyst recovery and
reuse.
Acknowledgements
We thank the National Natural Science Foundation of China
(Project No. 20862008) and the Natural Science Foundation
of Jiangxi Province in China (2007GZW0172) for financial
support.
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