Palladium catalyzed Mizoroki-Heck and Suzuki-Miyaura reactions using naphthalenomethyl-substituted imidazolidin-2-ylidene ligands in aqueous media

Article abstract of DOI:10.1080/00958972.2013.819092

Naphthalenomethyl-substituted imidazolidinium salts (1a-g) were prepared and characterized by conventional spectroscopic methods, ¹H NMR, ¹³C NMR, FTIR, and elemental analysis techniques. The in situ prepared three component systems naphthalenomethyl-substituted imidazolidinium salts, Pd(OAc)2, and K2CO3 catalyzed quantitatively the Mizoroki-Heck and Suzuki-Miyaura coupling of aryl halides under mild conditions in aqueous media.

Full text of DOI:10.1080/00958972.2013.819092

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Palladium catalyzed Mizoroki-Heck and Suzuki-Miyaura
reactions using naphthalenomethyl-substituted
imidazolidin-2-ylidene ligands in aqueous media
a
b
a
AYDIN AKTAŞ , SENEM AKKOÇ & YETKİN GÖK
a
Faculty of Science and Arts, Department of Chemistry , Inönü University , 44280 , Malatya ,
Turkey
b
Faculty of Science, Department of Chemistry , Erciyes University , 38039 , Kayseri , Turkey
Accepted author version posted online: 25 Jun 2013.
To cite this article: Journal of Coordination Chemistry (2013): Palladium catalyzed Mizoroki-Heck and Suzuki-Miyaura
reactions using naphthalenomethyl-substituted imidazolidin-2-ylidene ligands in aqueous media, Journal of Coordination
Chemistry, DOI: 10.1080/00958972.2013.819092
To link to this article: http://dx.doi.org/10.1080/00958972.2013.819092
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Palladium catalyzed Mizoroki-Heck and Suzuki-Miyaura reactions using
naphthalenomethyl-substituted imidazolidin-2-ylidene ligands in aqueous
media
AYDIN AKTAކ, SENEM AKKOÇ*‡ and YETKİN GÖK†
†
Faculty of Science and Arts, Department of Chemistry, Inönü University, 44280 Malatya, Turkey
Faculty of Science, Department of Chemistry, Erciyes University, 38039 Kayseri, Turkey
‡
Naphthalenomethyl-substituted imidazolidinium salts (1a-g) were prepared and characterized
1
13
by conventional spectroscopic methods, H NMR, C NMR, FT-IR and elemental analysis
techniques. The in situ prepared three component systems naphthalenomethyl-substituted
2 2 3
imidazolidinium salts, Pd(OAc) and K CO catalyzed quantitatively the Mizoroki-Heck and
Suzuki-Miyaura coupling of aryl halides under mild conditions in aqueous media.
Keywords: Imidazolidinium salt; Mizoroki-Heck reaction; Suzuki-Miyaura reaction;
Catalyst; N-Heterocyclic carbene
1. Introduction
Palladium catalyzed cross-coupling reactions for C-C bond formation have been recognized
as versatile and efficient methods. The Mizoroki-Heck cross-coupling reaction, which
consists of coupling of an alkene with a halo compound, has been developed from synthetic
and mechanistic points of view [1-3]. The Mizoroki-Heck reaction has been applied to many
areas such as in bioactive compounds, drug intermediates, natural products, fine chemical
syntheses, antioxidants, UV absorbers, and industrial applications [4-10]. The importance of
this reaction has transcended its applications in the laboratory and it has become of interest in
industry [11-15]. However, industrial applications of Mizoroki-Heck reactions are rare,
mainly due to two problems. First, palladium is expensive, and contamination of the product
by palladium has to be strictly controlled. Second, many phosphine ligands are even more
expensive and are air sensitive, poisonous, and subject to P-C bond degradation at elevated
temperatures.
The use of in situ formed bisbenzimidazole-benzimidazole–pyrimidine-imidazolidine-
2-ylidene-palladium(II) systems displayed high activities in various coupling reactions of aryl
bromides and aryl chlorides in studies conducted by our research groups [16-22]. To find
more stable, efficient and active ligand precursors, we prepared a series of seven new
*
Corresponding author. Email: senemakkoc@erciyes.edu.tr
1

1
-naphthalenomethyl-3-alkylimidazolidinium salts (scheme 1) and now report the use of the
in situ generated catalytic system consisting of Pd(OAc) as palladium source, 1a-g salts as
carbene precursors, and K CO as a base for cross-coupling of aryl halides with styrene
Mizoroki-Heck) or phenylboronic acid (Suzuki-Miyaura) in aqueous media.
2
2
3
(
2
. Experimental
.1. Materials and methods
2
All reactions for the preparation of 1-naphthalenomethyl-3-alkylimidazolidinium salts were
carried out under argon in flame dried glassware using standard Schlenk flasks. Test reactions
for the catalytic activity of the carbene ancillary ligands in the Mizoroki-Heck and Suzuki-
1
13
Miyaura coupling reactions were carried out in air. H NMR and C NMR spectra were
1
recorded using a Bruker AC300P FT spectrometer operating at 300.13 MHz ( H) and
1
3
7
5.47 MHz ( C). Chemical shifts (δ) are given in ppm relative to TMS, and coupling
constant (J) in Hz. With the use of an Electrothermal 9200 melting point apparatus, melting
points were measured in open capillary tubes. Elemental analyses were performed by the
TUBITAK Microlab Center (Turkey).
2
.2. General procedure for preparation of the imidazolidinium salts (1a-g)
Alkyl halide (1.0 mmol) was added slowly to a solution of 1-naphthalenomethylimidazolidine
1.0 mmol) in DMF (4 mL) at 25 °C and the resulting mixture was heated to 80 °C for 12 h.
(
Diethylether (15 mL) was added to obtain a white crystalline solid which was filtered off.
The solid was washed with diethylether (3×10 mL) and dried under vacuum. The crude
product was recrystallized from EtOH-Et O (1:2) at room temperature.
2
2.2.1. 1-3-Di(naphthalenomethyl)imidazolidinium chloride (1a). To a solution of
1-naphthalenomethylimidazolidine (1.0 mmol) in DMF (4 mL), 1-(chloromethyl)naphthalene
(
1.0 mmol) was added slowly at 25 °C. The resulting mixture was stirred at room temperature
for 2 h and then heated at 80 °C for 12 h. Diethyl ether (10 mL) was added to gain a white
crystalline solid, which was filtered off. The solid was washed with diethyl ether (3×10 mL),
dried under vacuum and recrystallized from EtOH/Et
2
O (1:2) at room temperature. Yield:
2%, m.p.: 217-218 °C, υ(C=N): 1651.6 cm . H NMR (300.13 MHz, CDCl ), δ 3.60 (s, 4H,
NCH CH N); 5.37 (s, 4H, NCH C H ); 7.37-8.21 (m, 14H, Ar-H); 11.12 (s, 1H, 2-CH).
-1 1
8
3
2
2
2
10
7
1
3
C NMR (75.47 MHz, CDCl
3
), δ 47.8 (NCH
2
2 2 10 7
CH N); 50.1 (NCH C H ); 123.1, 125.5, 126.6,
2

127.8, 128.1, 128.7, 129.2, 130.2, 131.3, and 134.4 (Ar-C); 159.2 (2-CH). Anal. calcd. for
25 23 2
C H N
Cl (%): C, 77.61; H, 5.99; N, 7.24. Found: C, 77.59; H, 6.00; N, 7.21.
2.2.2. 1-Naphthalenomethyl-3-benzylimidazolidinium chloride (1b). Compound 1b was
prepared in the same way as 1a, from 1-naphthalenomethylimidazolidine (1.0 mmol) and
-1 1
benzyl chloride (1.0 mmol). Yield: 75%, m.p.: 97-99 °C, υ(C=N): 1658.6 cm . H NMR
(
(
300.13 MHz, CDCl ), δ 3.61-3.70 (m, 4H, NCH CH N); 4.84 (s, 2H, NCH C H ); 5.35
3
2
2
2
6
5
13
s, 2H, NCH
), δ 47.5 and 48.1 (NCH
26.5, 127.6, 128.1, 128.3, 128.4, 128.6, 129.2, 130.1, 131.2, 132.5, and 133.9 (Ar-C); 159.0
2-CH). Anal. calcd. for C21 Cl (%): C, 74.88; H, 6.28; N, 8.32. Found: C, 74.76; H,
2
C
10
H
7
); 7.34-8.21 (m, 12H, Ar-H); 10.70 (s, 1H, 2-CH). C NMR (75.47 MHz,
CDCl
3
2
CH N); 50.0 (NCH ); 52.3 (NCH ); 122.9, 125.3,
2
2
C
6
H
5
2 10 7
C H
1
(
21 2
H N
6
.25; N, 8.33.
2.2.3.
1-Naphthalenomethyl-3-(2-methylbenzyl)imidazolidinium
chloride
(1c).
Compound 1c was prepared in the same way as 1a, from 1-naphthalenomethylimidazolidine
(
1.0 mmol) and 2-methylbenzyl chloride (1.0 mmol). Yield: 70%, m.p.: 99-101 °C, υ(C=N):
-1
1
1
638.3 cm . H NMR (300.13 MHz, CDCl
3
6 4 3
), δ 2.34 (s, 3H, C H CH -2); 3.61 and 3.68
(
m, 4H, NCH CH N); 4.87 (s, 2H, NCH C H CH -2); 5.41 (s, 2H, NCH C H ); 7.23 and
2 2 2 6 4 3 2 10 7
1
3
8
.23 (m, 11H, Ar-H); 10.48 (s, 1H, 2-CH). C NMR (75.47 MHz, CDCl
CH -2); 38.0, and 44.9 (NCH CH N); 47.9 (NCH CH -2); 50.0 (NCH
22.7, 125.3, 126.5, 127.6, 128.1, 128.2, 128.4, 128.7, 129.1, 129.3, 130.1, 131.2, and 133.9
Cl (%): C, 75.31; H, 6.61; N, 7.98. Found: C,
3
), δ 19.3
(C
6
H
4
3
2
2
2
C
6
H
4
3
2 10 7
C H
);
1
(Ar-C); 158.8 (2-CH). Anal. calcd. for C22
H
23
N
2
7
5.28; H, 6.71; N, 7.97.
2.2.4.
1-Naphthalenomethyl-3-(3-methylbenzyl)imidazolidinium
chloride
(1d).
Compound 1d was prepared in the same way as 1a, from 1-naphthalenomethylimidazolidine
(
1.0 mmol) and 3-methylbenzyl chloride (1.0 mmol). Yield: 81%, m.p.: 157-159 °C, υ(C=N):
-1 1
1
658.7 cm . H NMR (300.13 MHz, CDCl
3
), δ 2.63 (s, 3H, C
6
H
4
CH
3
-3); 3.23-3.38 (m, 4H,
NCH
2
CH N); 4.79 (s, 2H, NCH CH -3); 5.35 (s, 2H, NCH
2
2
C
6
H
4
3
2
C
10
H
7
); 7.37-8.33 (m, 11H,
1
3
Ar-H); 10.63 (s, 1H, 2-CH). C NMR (75.47 MHz, CDCl ), δ 22.9 (C H CH -3); 33.9 and
3
6
4
3
39.4 (NCH
2 2 2 6 4 3 2 10 7
CH N); 50.9 (NCH C H CH -3); 53.8 (NCH C H ); 124.9, 127.9, 128.2, 129.0,
129.9, 130.6, 131.3, 131.9, 132.5, 133.2, 135.5, and 136.1 (Ar-C); 167.4 (2-CH). Anal. calcd.
for C22
H
23
N
2
Cl (%): C, 75.31; H, 6.61; N, 7.98. Found: C, 75.42; H, 6.63; N, 7.95.
3

2.2.5.
1-Naphthalenomethyl-3-(4-methylbenzyl)imidazolidinium
chloride
(1e).
Compound 1e was prepared in the same way as 1a, from 1-naphthalenomethylimidazolidine
(
1.0 mmol) and 4-methylbenzyl chloride (1.0 mmol). Yield: 74%, m.p.: 186-187 °C, υ(C=N):
-1 1
1
657.1 cm . H NMR (300.13 MHz, CDCl ), δ 2.27 (s, 3H, C H CH -4); 3.58-3.70 (m, 4H,
3
6
4
3
NCH
2
CH
2
N); 4.75 (s, 2H, NCH
2
C
6
H
4
CH
3
-4); 5.36 (s, 2H, NCH
2
C
10
H
7
); 7.16-8.21 (m, 11H,
CH -4); 47.3 and
7.9 (NCH CH N); 49.9 (NCH C H CH -4); 52.0 (NCH C H ); 123.0, 125.4, 127.6, 128.2,
1
3
Ar-H); 10.74 (s, 1H, 2-CH). C NMR (75.47 MHz, CDCl
3
), δ 21.1 (C
6
H
4
3
4
1
2
2
2
6
4
3
2
10
7
28.6, 128.7, 129.4, 130.0, 131.2, and 133.9 (Ar-C); 158.8 (2-CH). Anal. calcd. for
C H N Cl (%): C, 75.31; H, 6.61; N, 7.98. Found: C, 75.39; H, 6.58; N, 7.93.
22
23
2
2
.2.6. 1-Naphthalenomethyl-3-(2,3,5,6-tetramethylbenzyl)imidazolidinium chloride (1f).
Compound 1f was prepared in the same way as 1a, from 1-naphthalenomethylimidazolidine
1.0 mmol) and 2,3,5,6-tetramethylbenzyl chloride (1.0 mmol). Yield 85%, m.p.: 245-247 °C,
(
-
1 1
υ(C=N): 1655.2 cm . H NMR (300.13 MHz, CDCl
,3,5,6]; 3.54-3.75 (m, 4H, NCH CH N); 4.89 [s, 2H, NCH
NCH
δ 15.9, and 20.4 [C
3
), δ 2.15 and 2.17 [s, 12H, C
6
H(CH
-2,3,5,6]; 5.40 (s, 2H,
),
3 4
) -
2
2
2
2
C
1
6
3
3 4
H(CH )
2
C
10
H
7
); 7.38-8.22 (m, 8H, Ar-H); 10.41 (s, 1H, 2-CH). C NMR (75.47 MHz, CDCl
3
6
H(CH -2,3,5,6]; 46.8, and 47.4 (NCH
3
)
4
2
CH
2
N); 47.8 [NCH
2
C
6
H(CH
3
)
4
-
2
1
7
,3,5,6]; 49.9 (NCH C H ); 123.1, 125.4, 126.4, 127.5, 128.0, 128.3, 128.7, 128.9, 130.0,
2 10 7
29 2
31.2, 132.7, 133.8, and 134.7 (Ar-C); 158.4 (2-CH). Anal. calcd. for C25H N Cl (%): C,
6.41; H, 7.44; N, 7.13. Found: C, 76.46; H, 7.38; N, 7.10.
2.2.7. 1-Naphthalenomethyl-3-(2,3,4,5,6-pentamethylbenzyl)imidazolidinium chloride
(1g). Compound 1g was prepared in the same way as 1a, from
1-naphthalenomethylimidazolidine (1.0 mmol) and 2,3,4,5,6-pentamethylbenzyl chloride
-
1 1
(
1.0 mmol). Yield: 69%, m.p.: 116-118 °C, υ(C=N): 1641.2 cm . H NMR (300.13 MHz,
CDCl ), δ 2.19, 2.20, and 2.24 [s, 15H, C (CH -2,3,4,5,6]; 3.61-3.98 (m, 4H, NCH CH N);
.92 [s, 2H, NCH (CH -2,3,4,5,6]; 5.39 (s, 2H, NCH ); 7.29-8.22 (m, 7H, Ar-H);
3
6
3
)
5
2
2
4
1
2
1
1
2
C
6
3
)
5
2 10 7
C H
13
0.05 (s, 1H, 2-CH). C NMR (75.47 MHz, CDCl ), δ 15.7, 15.9, and 20.5 [C (CH ) -
3
6
3 5
,3,4,5,6]; 46.7, and 47.8 (NCH
2
CH
2
N); 48.8 [NCH
2
C
6
(CH
3
)
5
-2,3,4,5,6]; 50.1 (NCH
2
C
10
H
7
);
22.7, 122.9, 125.4, 126.5, 127.5, 128.0, 128.3, 128.7, 129.1, 130.1, 131.2, 132.8, 133.2,
33.5, 133.8, 134.7, 156.4, and 157.9 (Ar-C); 158.1 (2-CH). Anal. calcd. for C26 Cl (%):
31 2
H N
C, 76.73; H, 7.68; N, 6.88. Found: C, 76.78; H, 7.66; N, 6.89.
4

2
.3. General procedure for the Mizoroki-Heck cross-coupling reactions
1
-Naphthalenomethyl-3-alkylimidazolidinium salts (1a-g) (2.0 mmol %), Pd(OAc)
2
2 3
(1.0 mmol %), styrene (1.5 mmol), aryl bromide (1.0 mmol), K CO (2.0 mmol), DMF
(3 mL) and water (3 mL) were added to a small Schlenk tube for the Mizoroki-Heck reaction
and the mixture was heated to 80 °C for 2 h. The Mizoroki-Heck cross-coupling reactions for
catalytic activities of the carbene ancillary ligands were carried out in the presence of air. At
the end of the Mizoroki-Heck cross-coupling reactions, the mixture was cooled, extracted
with hexane/ethylacetate (5:1), filtered through a pad of silica gel with copious washings,
concentrated and purified by flash chromatography on silica gel. The purity of the
compounds was checked by GC and NMR. Yields are based on arylbromide. All reactions
were monitored by GC-FID with an HP-5 column of 30 m length, 0.32 mm diameter and
0
.25 μm film thickness.
2
.4. General procedure for the Suzuki-Miyaura coupling reaction
Pd(OAc)
2
(1.0 mmol %), 1-naphthalenomethyl-3-alkylimidazolidinium salts (1a-g)
(
2.0 mmol %), aryl chloride (1.0 mmol), phenylboronic acid (1.5 mmol), K CO (2.0 mmol)
2
3
and water (2 mL) were added to a small Schlenk tube and the mixture was heated to 80 °C for
h. At the end of the reaction, the mixture was cooled, extracted with ethylacetate/hexane
1:5), filtered through a pad of silica gel with copious washings, concentrated, and purified by
2
(
flash chromatography on silica gel. The purity of the compounds was checked by NMR and
GC; yields were based on arylchloride.
3
3
. Results and discussion
.1. Synthesis and characterization of naphthalenomethyl-substituted imidazolidinium
salts (1a-g)
Naphthalenomethyl-substituted imidazolidinium salts (1a-g) are conventional NHC
precursors. These salts were obtained in almost quantitative yield by quaternization of
1-naphthalenomethylimidazolidine with various alkyl halides in DMF [23, 24] (scheme 1).
The structures of 1a-g were determined by their characteristic spectroscopic data and
1
elemental analysis. The H NMR spectra of the imidazolidinium salts further supported the
assigned structures; the resonances for C(2)-H were observed as sharp singlets at 11.12, 10.70,
13
1
0.48, 10.63, 10.74, 10.41, and 10.05 ppm for 1a-g, respectively. The C NMR chemical
5

shifts were consistent with the proposed structure; the imino carbon appeared as a typical
1
singlet in the H-decoupled mode at 159.2, 159.0, 158.8, 167.4, 158.8, 158.4, and 158.1 ppm
for 1a-g, respectively.
N
Cl
N
N
N
Cl
1b
Cl
N
N
1a
1
c
N
N
Cl
N
N
N
N
Cl
1d
1
g
N
N
N
N
Cl
Cl
1e
1f
Scheme 1. Synthesis of the naphthalenomethyl-substituted imidazolidinium salts, 1a-g.
6

3
.3. Mizoroki-Heck cross-coupling reaction
The palladium catalyzed coupling of styrene with various aryl bromides has been observed to
t
proceed under a variety of conditions. Diverse bases (K
2
CO
3
, Cs
2
CO
3
, and KOBu ) and
solvents (DMF, H
2
O, and dioxane), as well as ligand precursors, have been employed with
varying degrees of success according to the substrates. A series of experiments was
performed with styrene and 4-bromoacetophenone as model compounds to find optimum
conditions. K CO as a base was the best choice in DMF/water systems. Water was used as
2
3
solvent in the Mizoroki-Heck cross-coupling reactions because it is inexpensive,
nonflammable, nontoxic, abundant, and readily separable from organic compounds. The
reactions were performed in air and without degassing water prior to use. Under the reaction
conditions using 1a-g as ligands, Pd(OAc)
2
as the catalyst, DMF-water mixture as the solvent
and K CO as the base at 80 °C, various aryl bromides and styrene were examined (table 1).
2
3
After establishing the optimized coupling reaction conditions, the scope of the reaction and
efficiencies of the salts were evaluated by investigating the coupling of various p-substituted
aryl bromides with styrene. The corresponding products C were obtained in good yields. The
results are given in table 1.
We conducted control experiments (not using ligand precursors) by using
p-bromoacetophenone and found that the reaction resulted in a 4% yield. This result shows
that the synthesized ligand precursors are very efficient in the Mizoroki-Heck and Suzuki-
Miyaura coupling reactions.
The ligand precursors used for Mizoroki-Heck reactions were stable against air and
moisture. These ligands render the design of goal-oriented catalysts possible because their
steric and electronic effects can be easily changed. Electron-poor arylbromides, such as
p-bromobenzaldehyde or p-bromoacetophenone, were equally effective in the presence of
catalysts generated from imidazolidinium salts and excellent yields were obtained when
coupled with styrene (table 1, entries 1-14). Reactions of electron-rich arylbromides, such as
p-bromoanisole or p-bromotoluene, with a number of styrenes resulted in full conversion to
give the desired products after 2 h at 80 °C in excellent yields (table 1, entries 15-28). The
Mizoroki-Heck coupling reaction using the synthesized ligand precursors gave yields of
87-100%.
7

3
.3. Suzuki-Miyaura coupling reaction
The palladium-catalyzed Suzuki-Miyaura cross-coupling reaction of aryl halides and pseudo-
halides is a common method employed for formation of C-C bonds. The coupling of aryl
halides with phenylboronic acid has been used in the synthesis of several industrially
applicable compounds along with a number of natural products. The ability to use aryl
chlorides as substrates in Suzuki-Miyaura coupling reactions is advantageous for two reasons.
First, aryl chlorides are more commercially available than aryl bromides. Second, they are
much less expensive [25]. The search for catalysts that can activate these substrates is a
highly topical field of study. Development of catalysts used with aryl chlorides [26] and aryl
bromides has been reported by Buchwald [27], Fu [28], Bedford [29], Beller [30], Gök [31],
and others [32].
2
In 1a-g/Pd(OAc) catalyst, chlorobenzene and phenylboronic acid were examined in
the Suzuki-Miyaura coupling as the model reaction with water as solvent. The yield of the
Suzuki-Miyaura cross-coupling reaction is between 89 and 94% (table 2). Thus, synthesized
imidazolidinium salts are effective carbene ancillary ligands in the Mizoroki-Heck and
Suzuki-Miyaura cross-coupling reactions.
In our previous study, catalytic activities in the Mizoroki-Heck and Suzuki-Miyaura
coupling (DMF-water) reactions of N-phenyl-substituted benzimidazolium salts were
examined [18]. In this study, catalytic activity of Mizoroki-Heck (DMF-water mixture as
solvent) and Suzuki-Miyaura (water as solvent) coupling of synthesized naphthalene
substituted imidazolidinium salts were analyzed. We conclude that imidazolidinium salts or
benzimidazolium salts in the Mizoroki-Heck and Suzuki-Miyaura coupling reactions show
high activity. Instead of using DMF-water as solvent in Suzuki-Miyaura coupling, the
reaction occurred in high yields when water was used as solvent as well.
4
. Conclusions
Seven new saturated and unsaturated carbene ancillary ligands were synthesized and
1
13
characterized using FT-IR, H NMR, C NMR and elemental analyses. The catalytic
behavior of the imidazolidinium salts (1a-g) was investigated in the Mizoroki-Heck and
Suzuki-Miyaura reactions, processes which are environmentally benign, easy to handle and
highly effective. Use of the in situ formed naphthalenomethyl-substituted imidazolidin-2-
ylidene palladium(II) systems exhibited high catalytic activity.
8

Acknowledgements
This work was financially supported by Inönü University Research Fund (I.U.B.A.P.
2011/130).
References
[
[
1]
2]
B.M. Trost. Science, 234, 1471 (1991).
J. Tsuji, Palladium Reagents and Catalysts: Innovations in Organic Synthesis; Wiley:
New York, NY (1995).
[
[
3]
4]
E. Negishi, A. de Meijere, Handbook of Organopalladium Chemistry for Organic
Synthesis; Eds.; John Wiley: New York, NY (2002).
J. Tsuji, Palladium Reagents and Catalysts: Innovations in Organic Synthesis; Wiley,
Chichester, UK (1995).
[
[
5]
6]
S. Liu, X. Jiang, G. Zhuo. J. Mol. Catal. A: Chem., 290, 72 (2008).
A. Kumar, M. Agarwal, A.K. Singh, R.J. Butcher. Inorg. Chim. Acta, 362, 3208
(2009).
[
[
7]
8]
C. Mazet, L.H. Gade. Eur. J. Inorg. Chem., 2003, 1161 (2003).
H. Türkmen, T. Pape, F.E. Hahn, B. Çetinkaya. Eur. J. Inorg. Chem., 2009, 285
(2009).
[
[
[
9]
B. Yiğit, Y. Gök, İ. Özdemir, S. Günal. J. Coord. Chem., 65, 371 (2012).
10] A. Kumar, P. Ghosh. Eur. J. Inorg. Chem., 3955 (2012).
11] S.T. Henriksen, P.O. Norrby, P. Kaukoranta, P.G. Andersson. J. Am. Chem. Soc., 130,
10414 (2008).
[
[
[
[
12] R.F. Heck, J.P. Nolley. J. Org. Chem., 37, 2320 (1972).
13] I.P. Beletskaya, A.V. Cheprakov. Chem. Rev., 100, 3009 (2000).
14] L. Yi, J. Liebscher. Chem. Rev., 107, 133 (2007).
15] R.T. Ruck, M.A. Huffman, M.M. Kim, M. Shevlin, W.V. Kandur, W. Daviesi. Angew.
Chem. Int. Ed., 47, 4711 (2008).
[
[
16] S. Demir, İ. Özdemir, B. Çetinkaya. Appl. Organomet. Chem., 23, 520 (2009).
17] İ. Özdemir, Y. Gök, N. Gürbüz, S. Yaşar, E. Çetinkaya, B. Çetinkaya. Polish J. Chem.,
7
8, 2141 (2004).
[
[
18] S. Akkoç, Y. Gök. J. Coord. Chem., 66, 1396 (2013).
19] H. Türkmen, S. Denizaltı, İ. Özdemir, E. Çetinkaya, B. Çetinkaya. J. Organomet.
Chem., 693, 425 (2008).
9

[
20] Y. Gök, N. Gürbüz, İ. Özdemir, B. Çetinkaya, E. Çetinkaya. Appl. Organomet. Chem.,
9, 870 (2005).
1
[
[
[
21] B. Yiğit, M. Yiğit, İ. Özdemir, E. Çetinkaya. Turk. J. Chem., 34, 327 (2010).
22] A. Slamani, S. Demir, İ. Özdemir. Catal. Commun., 29, 141 (2012).
23] A.C. Hillier, G.A. Grasa, M.S. Viciu, H.M. Lee, C.L. Yang, S.P. Nolan. J. Organomet.
Chem., 653, 69 (2002).
[
[
24] C.M. Zhang, M.L. Trudell. Tetrahedron Lett., 41, 595 (2000).
25] İ. Özdemir, N. Şahin, Y. Gök, S. Demir, B. Çetinkaya. J. Mol. Catal. A: Chem., 234,
181 (2005).
[
[
[
[
26] A.F. Littke, G.C. Fu. Angew. Chem. Int. Ed., 41, 4176 (2002).
27] J.P. Wolfe, S.L. Buchwald. Angew. Chem. Int. Ed., 38, 2413 (1999).
28] A.F. Littke, C. Dai, G.C. Fu. J. Am. Chem. Soc., 122, 4020 (2000).
29] R.B. Bedford, C.S.J. Cazin, S.J. Coles, T. Gelbrich, P.N. Horton, M.B. Hursthouse,
M.E. Light. Organometallics, 22, 2810 (2003).
[
[
[
30] A. Zapf, R. Jackstell, F. Rataboul, T. Riermeier, A. Monsees, C. Fuhrmann, N. Shaikh,
U. Dingerdissen, M. Beller. Chem. Commun., 38 (2004).
31] Y. Gök, E. Çetinkaya, İ. Özdemir, B. Çetinkaya, M.F. Lappert. Acta Chim. Slov., 51,
437 (2004).
32] R.A. Singer, S. Caron, R.E. McDermott, P. Arpin, N.M. Do. Synlett, 12, 1727 (2003).
1
0

Table 1. Mizoroki-Heck coupling of various aryl bromides with styrene in the presence of
in situ generated catalysts from different imidazolium salts.
Pd(OAc) (1 mol %)
2
1
a-g (2 mol %)
R
Br
R
DMF/H O, K CO
2
2
3
A
B
C
Entry
R
LHX
Product
Yield (%)
89
1
2
3
4
5
6
7
8
9
COCH
3
1a
1b
1c
1d
1e
1f
COCH3
91
COCH
COCH
COCH
COCH
3
3
3
3
97
COCH3
99
98
99
COCH3
CHO
CHO
CHO
CHO
CHO
CHO
CHO
1g
1a
1b
1c
1d
1e
1f
94
90
96
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
94
CHO
OCH3
CH3
98
94
96
1g
1a
1b
1c
1d
1e
1f
87
OCH
3
95
OCH3
100
91
OCH
OCH
3
3
100
91
OCH3
OCH
OCH
3
3
99
1g
1a
1b
1c
1d
1e
1f
91
CH
3
87
CH3
89
CH
CH
3
3
92
92
CH3
94
CH
CH
3
3
94
1g
93
1
1

2
3
3
3
3
3
3
9
0
1
2
3
4
5
H
H
H
H
H
H
H
1a
1b
1c
1d
1e
1f
91
99
97
H
97
94
99
1g
100
a
Reaction conditions: styrene (1.5 mmol), p-R-C H Br (1.0 mmol), Pd(OAc)
2
6
4
(
8
1.0 mmol %), K
2
CO
3
(2.0 mmol), 1 (2.0 mmol %), water (3 mL)-DMF (3 mL),
b
0 °C, 2 h. The purity of the compounds was checked by NMR and GC spectroscopy.
c
d
Yields are based on arylbromide. Isolated yields.
1
2

Table 2. The Suzuki-Miyaura coupling of aryl chlorides with phenyl boronic acid.
Pd(OAc)2 (1 mmol %)
1
a-g (2 mmol %)
Cl
+
B(OH)
2
K CO , H O
2
3
2
Entry
1
Chlorobenzene
LHX
Product
Yield (%)
94
1a
1b
1c
1d
1e
1f
2
3
4
5
6
7
93
89
92
92
90
91
Cl
1g
Reaction conditions: C
Pd(OAc) (1.0 mmol %), K
0 °C, 2 h.
6
H
5
Cl (1.0 mmol), phenylboronic acid (1.5 mmol),
CO (2.0 mmol), 1a-g (2.0 mmol %), water (2 mL),
2
2
3
8
1
3