2-(diphenylphosphino)pyridine platinum (I) and palladium (I) complex as an efficient binuclear catalyst for Suzuki-Miyaura coupling reaction in water under mild reaction conditions

Article abstract of DOI:10.1016/j.jorganchem.2015.05.047

Binuclear complex of platinum (I) and palladium (I) showed superior activity in Suzuki-Miyaura coupling reaction of aryl halides with arylboronic acids compared to the sole palladium or platinum species. The catalyst showed good tolerance in water and coupling reactions were performed in water as a green solvent. Aryl iodides were reacted at room temperature and the reactions of aryl bromides were performed at 60 °C.

Full text of DOI:10.1016/j.jorganchem.2015.05.047

Journal of Organometallic Chemistry xxx (2015) 1e8
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Journal of Organometallic Chemistry
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2-(diphenylphosphino)pyridine platinum (I) and palladium (I)
complex as an efficient binuclear catalyst for Suzuki-Miyaura coupling
reaction in water under mild reaction conditions
Mohammad Gholinejad*, Hamid R. Shahsavari*, Mehran Razeghi, Maryam Niazi,
Fatemeh Hamed
Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), PO-Box 45195-1159, Gava zang, Zanjan, 45137-6731, Iran
a r t i c l e i n f o
a b s t r a c t
Article history:
Binuclear complex of platinum (I) and palladium (I) showed superior activity in Suzuki-Miyaura coupling
reaction of aryl halides with arylboronic acids compared to the sole palladium or platinum species. The
catalyst showed good tolerance in water and coupling reactions were performed in water as a green
solvent. Aryl iodides were reacted at room temperature and the reactions of aryl bromides were per-
formed at 60 ꢀC.
Received 2 February 2015
Received in revised form
10 May 2015
Accepted 11 May 2015
Available online xxx
© 2015 Elsevier B.V. All rights reserved.
Keywords:
Platinum
Palladium
Binuclear
Suzuki
Water
1. Introduction
In recent years bimetallic catalysts have attracted great atten-
tion in the field of catalysts [24,25]. In fact, synergistic combination
Palladium has found such wide utility because it affects an
extraordinary number of very different reactions, including many
carbonecarbon bond-forming reactions [1e5]. Among the different
types of palladium catalyzed reactions, Suzuki-Miyaura coupling
reaction, which is the reaction of organic electrophiles, such as aryl
or alkenyl halides and triflates with organoboron compounds in
the presence of a base, is one of the important organic reactions
[6e14]. Despite numerous reports on development of Suzuki-
Miyaura coupling reaction, efforts to improve the conditions of
the reaction are still in progress. Along this line, improving the low
reactivity of aryl bromides and chlorides, introducing of new effi-
cient catalysts, using recyclable heterogeneous catalysts, short-
ening of the reaction times and conducting reactions in eco-
friendly solvents such as water are challenging subjects for inves-
tigation [6e23].
of two metals enhances their catalytic performance, activity,
selectivity, and stability compared to corresponding monometallic
catalysts. Along this line, catalytic activity of palladium catalysts in
the presence of other transition metals in coupling reactions were
investigated. NiFe2O4-dopamine-Pd composite has been found as a
magnetically separable and efficient catalyst for Heck CeC coupling
reactions [26].
Recently, Pd/Cu bimetallic composite nanoparticles exhibited
high catalytic activity in the Sonogashira cross-coupling reaction
between aryl iodide and terminal alkynes [27]. Also, bimetallic Au/
Pd alloy nanoclusters showed excellent reactivity for Ullmann
coupling of chloroarenes in aqueous media at low temperature
[28,29]. Recently, we have demonstrated synergistic effect between
palladium and copper species using copper ferrite supported
palladium nanoparticles in cyanation reaction of aryl halides [30].
Most recently, we have also reported assemblies of copper ferrite
and palladium nanoparticles on silica spheres as a bimetallic
catalyst for Sonogashira coupling reaction [31]. However, among
the different types of bimetallic catalysts, platinum based bime-
tallic catalysts are most commonly used in catalytic and electro
* Corresponding authors.
E-mail addresses: gholinejad@iasbs.ac.ir (M. Gholinejad), shahsavari@iasbs.ac.ir
(H.R. Shahsavari).
http://dx.doi.org/10.1016/j.jorganchem.2015.05.047
0022-328X/© 2015 Elsevier B.V. All rights reserved.
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M. Gholinejad et al. / Journal of Organometallic Chemistry xxx (2015) 1e8
Scheme 1. Synthesis of binuclear complexes of platinum (I) and palladium (I) involving 2-(diphenylphosphino)pyridine as a bridging ligand.
catalytic applications [32]. Literature search reveals that there is
only one report on using platinum catalyzed Suzuki-Miyaura
coupling reaction and platinum based catalysts are not potent
catalysts for coupling reactions [33]. However, combination of
second metal such as palladium with platinum can increase cata-
lytic activity of new bimetallic catalyst [32].
Very recently, synergistic effect of a conjugated organometallic
platinum moiety with palladium was applied in Suzuki and Heck
coupling reactions of aryl bromides under mild reaction conditions
[34,35]. Now in this article, we have introduced binuclear complex
of platinum (I) and palladium (I) catalyst involving 2-(diphenyl-
phosphino)pyridine ligand (Scheme 1) as a highly efficient catalyst
in Suzuki-Miyaura coupling reactions in neat water under mild
reaction conditions.
Pt(Ph2Ppy)2Cl2 in CH2Cl2 (Scheme 1) and was characterized using
1H (see supporting information) and 31P{1H} NMR spectroscopy.
31P{1H} NMR of the catalyst in CDCl3 shows two different signals
for phosphorus atoms (Fig. 1). The Pa atom bonded to the platinum
center is appeared at
d
¼ ꢁ7.6 ppm with a large platinum coupling
1
constant JPtP ¼ 4047 Hz, whereas the Pb atom bonded to the
palladium atom is observed at
d
¼ 7.0 ppm with a much smaller
platinum coupling constant 2JPtP value of 111 Hz. It is interesting to
note, due to PaPb coupling, the two non-equivalent phosphorus
atoms in this catalyst are coupled to each other through the PtePd
metal bond and so each resonance appears as a doublet with
3 ab
J
¼ 14 Hz.
PP
The thermogravimetric analysis (TGA) curve of catalyst has
been shown in Fig. 2. According to this curve, the prepared catalyst
has high thermal stability and negligible ligand leaching up to
200 ꢀC.
The catalyst successfully was prepared according to the reported
method by Balch and coworker [36] using Pd2(dba)3.CHCl3 and
Fig. 1. 31P{1H} NMR of catalyst in CDCl3.
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M. Gholinejad et al. / Journal of Organometallic Chemistry xxx (2015) 1e8
3
at 60 ꢀC afforded excellent yields in shorter reaction times. In
addition, aryl bromides reacted efficiently with arylboronic acids
and gave coupling products in high to excellent yields (Table 2,
entries 11e22). Reactions of aryl chlorides under optimized reac-
tion conditions were sluggish. Therefore, we increased reaction
temperature to 80 ꢀC. Under this condition, desired coupling
products were obtained in 47e56% isolated yields (Table 2, entries
23e24). Also, results of Table 2 indicated that heterocyclic aryl
halides such as 2-iodothiophene and 5-bromopyrimidine were
reacted efficiently and produced coupling products in 80e97%
yields (Table 2, entries 9 and 18e19).
The catalyst is not soluble in the reaction medium and reactions
proceeded under heterogeneous reaction conditions. However, in
order to confirm the heterogeneity of catalyst, we have studied hot
filtration test for the reaction of 4-bromoanisol and phenylboronic
acid. The reaction mixture was filtered after 8 h at the reaction
temperature and GC analysis showed 46% GC yield. Then, filtrate
allowed reacting for 24 h. GC analysis of reaction after 24 h showed
57% yield.
In addition, we have also studied poisoning test using poly(4-
vinylpyridine) with ratio of 400: 1 with respect to the catalyst for
the reaction of 4-bromoanisol and phenylboronic acid under opti-
mized reaction conditions. GC analysis of the reaction showed 69%
conversion to desired coupling product while, similar reaction in
the absence of poisoning was produced 86% GC yield. This result
also confirmed that reaction proceeded mostly under heteroge-
neous conditions [40].
Fig. 2. Thermogravimetric diagram of the catalyst.
Table 1
Screening of different reaction conditions for the reaction of 4-bromoanisole with
phenylboronic acid in the presence of catalyst.
Furthermore, leaching of the catalyst into the reaction mixture
after 24 h was determined by atomic absorption spectroscopy to be
3.5%. Therefore, we assume that the catalyst predominantly have
a heterogeneous nature at the reaction conditions.
In order to confirm the synergistic effect between Pd and Pt
species in the catalyst, we have performed reaction of 4-
bromoanisole with phenylboronic acid in the presence of sole Pd
and Pt species under optimized reaction conditions (Scheme 2).
However, results indicated that in the presence of corresponding
monometallic catalysts, low isolated yields of products were
obtained.
It is worth mentioning that it is difficult to recognize how the
electronic and chemical properties of bimetallic systems affected
property of them, compared to individual metals [24,25]. The
observed superior activity in the presented platinum (I) and
palladium (I) catalyst may related to electron exchange between
palladium and platinum which cause the modifications of the
chemical and catalytic property of the catalyst.
Entry
Solvent
Base
Temp. (ꢀ C)
Yield(%)a
1
2
3
4
5
6
7
8
CH3CN
Toluene
THF
DMF
H2O
H2OeEtOH
H2OeEtOH
H2O
H2O
H2O
H2OeEtOH
H2OeEtOH
H2OeEtOH
H2OeEtOH
DMF
K3PO4
K3PO4
K3PO4
K3PO4
K3PO4
K3PO4
K3PO4
t-BuOK
DABCO
K2CO3
K2CO3
t-BuOK
DABCO
Et3N
60
60
60
60
60
60
50
50
50
50
60
60
60
60
60
5
19
7
21
86
73
35
51
52
60
10
16
56
54
4
9
10
11
12
13
14
15
DABCO
a
GC yields.
2. Results and discussion
3. Conclusions
The catalytic activity of prepared catalyst were assessed in
Suzuki-Miyaura coupling reaction. In initial experiments, reaction
of less reactive 4-bromoanisole with phenylboronic acid was
selected as a model reaction and effect of different reaction con-
ditions such base, solvent and temperature was studied (Table 1).
The results of Table 1 indicated that using K3PO4 as a base and
H2O as a solvent at 60 ꢀC in the presence of the catalyst are the most
effective reaction conditions for the reaction of 4-bromoanisole
with phenylboronic acid. The scope of the reaction was further
expanded for the reactions of structurally varied aryl halides
under optimized reaction conditions (Table 2). Due to more reac-
tivity of aryl iodides than aryl bromides and chlorides, we decided
to perform reactions of aryl iodides in both 60 ꢀC and room tem-
perature under optimized reaction conditions (Table 2, entries
1e10). The results of Table 2 indicated that reactions of aryl
iodides with arylboronic acids proceeded well at room temperature
and desired biphenyl products were obtained in excellent yields
(Table 2, entries 2,3, and 5e10). However, reactions of aryl iodides
In conclusion, we have described application of binuclear
complex of platinum (I) and palladium (I) as an efficient catalyst
for Suzuki-Miyaura coupling reaction of aryl halides in aqueous
media. Using this catalyst, aryl iodides and bromides were reacted
effectively at 25e60 ꢀC and high to excellent isolated yields were
obtained. Reactions of aryl chlorides were sluggish and moderate
isolated yields were obtained.
4. Experimental
4.1. General
The 1H, 13C and 31P NMR spectra were recorded on a Bruker
Avance DPX 400 MHz spectrometer. The operating frequencies and
references, respectively, are shown in parentheses as follows:
1H (400 MHz, TMS), 13C (100 MHz, TMS) and 31P (162 MHz, 85%
H3PO4). The chemical shifts and coupling constants are in ppm and
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M. Gholinejad et al. / Journal of Organometallic Chemistry xxx (2015) 1e8
Table 2
Reactions of structurally different aryl halides with arylboronic acids in the presence of the catalyst.a
Entry
1
Ar1X
Temp. (ꢀC)
Ar2
Ph
Time
0.5
Product
Isolated yield(%)
99
60
2
25
25
60
25
25
25
25
25
25
Ph
15
15
2
83
98
95
96
94
75
80
97
72
3
Ph
4
Ph
5
4-MeOC6H4-
15
15
3
6
Ph
7
Ph
8
4-MeOC6H4-
3
9
Ph
Ph
5
10
24
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M. Gholinejad et al. / Journal of Organometallic Chemistry xxx (2015) 1e8
5
Table 2 (continued )
Entry
Ar1X
Temp. (ꢀC)
60
Ar2
Ph
Time
24
Product
Isolated yield(%)
86
11
12
13
14
15
60
60
60
60
Ph
24
24
24
2
81
91
87
90
4-MeOC6H4-
4-MeC6H4-
Ph
16
17
18
60
60
60
Ph
Ph
Ph
10
24
20
92
86
80
83
19
20
60
60
4-MeC6H4-
24
24
Ph
75
(continued on next page)
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M. Gholinejad et al. / Journal of Organometallic Chemistry xxx (2015) 1e8
Table 2 (continued )
Entry
Ar1X
Temp. (ꢀC)
Ar2
Time
10
Product
Isolated yield(%)
21
60
1-naphthyl
96
22
23
60
80
80
1-naphthyl
24
24
24
76
56
47
Ph
24
Ph
a
Reaction conditions: ArX (1 mmol), ArB(OH)2 (1.5 mmol), K3PO4 (1.5 mmol), H2O (2 mL), and catalyst 0.8 mol%.
Scheme 2. Reaction of 4-bromoanisole with phenylboronic acid in the presence of sole Pd and Pt species.
Hz, respectively. The microanalyses were performed using a Ther-
mofinigan Flash EA-1112 CHNSO rapid elemental analyzer. The
progress of the reactions was followed with TLC using silica gel
SILG/UV 254 plates or by GC Varian CP 3800 instrument.
Pt(Ph2Ppy)2Cl2 [37], Pd(Ph2Ppy)2Cl2 [38] and Pd2(dba)3.CHCl3 [39]
were prepared according to literature methods.
added slowly to precipitate a greenish brown solid. The precipitate
was collected by filtration and dried by vacuum. Yield 0.085 g, 73%.
C
34H28Cl2N2P2PdPt (MW ¼ 898.95): calcd. C 45.43, H 3.14, N, 3.12.
Found: C 45.21, H 3.13, N 3.48. 1H NMR in CDCl3:
d
9.61e9.50 (m,
2H), 7.75e7.32 (m, 24H), 6.78e6.67 (m, 2H). 31P NMR in CDCl3:
d
ꢁ7.6 (d, 3JaPPb ¼ 14 Hz, 1JPtP ¼ 4047 Hz, 1 P, Pa bonded to the Pt), 32.4
(d, 3JaPPb ¼ 14 Hz, 1JPtP ¼ 111 Hz, 1 P, Pb bonded to the Pd) ppm.
4.2. General procedure for the preparation of catalyst
4.3. General procedure for the SuzukieMiyaura reaction
The catalyst was prepared according to the reported procedure
in the literature [36], which briefly will explain here. A solution
containing Pd2(dba)3.CHCl3 (0.149 g, 0.15 mmol) and Pt(Ph2Ppy)2Cl2
(0.237 g, 0.30 mmol) in 50 mL of dichloromethane was heated in
reflux condition for 2 h under nitrogen atmosphere. Then the so-
lution was cooled to room temperature, and diethyl ether was
Aryl halide (1 mmol), arylboronic acid (1.5 mmol), catalyst
(0.8 mol%), K3PO4 (1.5 mmol) and distilled water (2 mL) were added
to a 5 mL flask. The mixture was stirred for appropriate reaction
time at 25 ꢀC for aryl iodides, 60 ꢀC for aryl bromides and 80 ꢀC for
aryl chlorides. The progress of the reaction was monitored by GC.
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M. Gholinejad et al. / Journal of Organometallic Chemistry xxx (2015) 1e8
7
After completion of the reaction, the aqueous layer was extracted
Appendix A. Supplementary data
with ethyl acetate or hexane (5 ꢂ 1 mL) and further purified by
column chromatography using hexane and ethyl acetate as an
eluant.
Supplementary data related to this article can be found at http://
dx.doi.org/10.1016/j.jorganchem.2015.05.047.
1a. 1H NMR (400 MHz, CDCl3)
d
(ppm): 7.61 (d, J ¼ 7.7, 2H), 7.45
(t, J ¼ 7.6, 2H), 7.36 (t, J ¼ 7.3, 1H); 13C NMR (101 MHz, CDCl3)
References
d
(ppm): 141.4, 128.9, 127.4, 127.3.
2a. 1H NMR (400 MHz, CDCl3)
d
(ppm): 7.55 (t, J ¼ 8.2, 4H), 7.42
ꢀ
ꢀ
[1] A. Molnar, Palladium-catalyzed coupling reactions: practical aspects and
future developments, in: Palladium-catalyzed Coupling Reactions: Practical
Aspects and Future Developments, Wiley-VCH Verlag GmbH & Co. KGaA,
2013.
(t, J ¼ 7.6, 2H), 7.31 (t, J ¼ 7.3, 1H), 6.98 (d, J ¼ 8.7, 2H), 3.86 (s, 3H);
13C NMR (101 MHz, CDCl3)
126.9, 126.8, 114.3, 55.5.
d (ppm): 159.3, 141.0, 134.0, 128.9, 128.3,
ꢀ
ꢀ
[2] A. Molnar, Efficient, selective, and recyclable palladium catalysts in carbon-
ꢁcarbon coupling reactions, Chem. Rev. 111 (2011) 2251e2320.
[3] R. Jana, T.P. Pathak, M.S. Sigman, Advances in transition metal (Pd,Ni,Fe)-
catalyzed cross-coupling reactions using alkyl-organometallics as reaction
partners, Chem. Rev. 111 (2011) 1417e1492.
3a. 1H NMR (400 MHz, CDCl3)
d
(ppm): 7.48 (d, J ¼ 8.6, 2H), 6.96
(d, J ¼ 8.7, 2H), 3.85 (s, 3H); 13C NMR (101 MHz, CDCl3)
d (ppm):
158.8, 133.6, 127.9, 114.3, 55.46.
4a. 1H NMR (400 MHz, CDCl3)
d
(ppm): 7.70 (d, J ¼ 7.1, 2H), 7.62
[4] M. Lamblin, L. Nassar-Hardy, J.C. Hierso, E. Fouquet, F.X. Felpin, Recyclable
heterogeneous palladium catalysts in pure water: sustainable developments
in Suzuki, Heck, Sonogashira and Tsuji-Trost reactions, Adv. Synth. Catal. 352
(2010) 33e79.
(d, J ¼ 8.1, 2H), 7.54 (t, J ¼ 7.6, 2H), 7.44 (t, J ¼ 7.4, 1H), 7.36 (d, J ¼ 7.9,
2H), 2.51 (s, 3H); 13C NMR (101 MHz, CDCl3)
137.1, 129.6, 128.8, 127.1, 127.0, 21.2.
d (ppm): 141.3, 138.5,
€
[5] B.C.G. Soderberg, Transition metals in organic synthesis: highlights for the
year 2000, Coord. Chem. Rev. 241 (2003) 147e247.
[6] D.A. Alonso, C. Najera, Oxime-derived palladacycles as source of palladium
nanoparticles, Chem. Soc. Rev. 39 (2010) 2891e2902.
[7] F. Alonso, I.P. Beletskaya, M. Yus, Non-conventional methodologies for
transition-metal catalysed carbon-carbon coupling: a critical overview. Part 2:
the Suzuki reaction, Tetrahedron 64 (2008) 3047e3101.
5a. 1H NMR (400 MHz, CDCl3)
d
(ppm): 8.30 (d, J ¼ 8.8, 2H), 7.74
(d, J ¼ 8.8, 2H), 7.63 (d, J ¼ 7.7, 2H), 7.48 (m, 3H); 13C NMR (101 MHz,
CDCl3)
d (ppm): 147.8, 147.2, 138.9, 129.3, 129.1, 128.0, 127.5, 124.3.
6a. 1H NMR (400 MHz, CDCl3)
d
(ppm): 8.26 (d, J ¼ 8.8, 2H), 7.68
(d, J ¼ 8.8, 2H), 7.58 (d, J ¼ 8.7, 2H), 7.02 (d, J ¼ 8.7, 2H), 3.87 (s, 3H);
[8] M. Blangetti, H. Rosso, C. Prandi, A. Deagostino, P. Venturello, Suzuki-Miyaura
cross-coupling in acylation reactions, scope and recent developments, Mole-
cules 18 (2013) 1188e1213.
13C NMR (101 MHz, CDCl3)
127.1, 124.2, 114.7, 55.51.
d (ppm): 160.5, 147.3, 146.6, 131.1, 128.7,
[9] M. Gholinejad, H.R. Shahsavari, N,N0-bis(2-pyridinecarboxamide)-1,2-benzene
palladium complex as a new efficient catalyst for SuzukieMiyaura coupling
reaction under phosphane free conditions, Inorg. Chim. Acta 421 (2014)
433e438.
7a. 1H NMR (400 MHz, CDCl3)
d
(ppm): 7.62 (d, J ¼ 7.3, 2H), 7.38
(t, J ¼ 7.6, 2H), 7.32e7.28 (m, 3H), 7.08 (dd, J ¼ 5.0, 3.6, 1H); 13C NMR
(101 MHz, CDCl3)
125.1, 123.3.
d (ppm): 144.7, 134.6, 129.1, 128.2, 127.7, 126.2,
ꢀ
[10] J. Hassan, M. Sevignon, C. Gozzi, E. Schulz, M. Lemaire, Arylꢁaryl bond for-
mation one century after the discovery of the Ullmann reaction, Chem. Rev.
102 (2002) 1359e1470.
8a. 1H NMR (400 MHz, CDCl3)
d
(ppm): 7.50 (t, J ¼ 7.3, 2H), 7.43
(t, J ¼ 7.1, 3H), 7.3e7.33 (m, 4H), 2.37 (s, 3H); 13C NMR (101 MHz,
[11] S. Kotha, K. Lahiri, D. Kashinath, Recent applications of the SuzukieMiyaura
cross-coupling reaction in organic synthesis, Tetrahedron 58 (2002)
9633e9695.
CDCl3)
d (ppm): 142.1, 135.5, 130.4, 129.9, 129.3, 128.9, 128.2, 127.4,
126.9, 125.9, 20.6.
[12] V. Polshettiwar, A. Decottignies, C. Len, A. Fihri, SuzukieMiyaura cross-
coupling reactions in aqueous media: green and sustainable syntheses of
biaryls, ChemSusChem 3 (2010) 502e522.
[13] R. Rossi, F. Bellina, M. Lessi, Selective palladium-catalyzed SuzukieMiyaura
reactions of polyhalogenated heteroarenes, Adv. Synth. Catal. 354 (2012)
1181e1255.
[14] A. Suzuki, Recent advances in the cross-coupling reactions of organoboron
derivatives with organic electrophiles, 1995e1998, J. Organomet. Chem. 576
(1999) 147e168.
9a. 1H NMR (400 MHz, CDCl3)
d
(ppm): 7.57 (d, J ¼ 8.7, 2H), 7.51
(d, J ¼ 8.0, 2H), 7.28 (d, J ¼ 8.0, 2H), 7.02 (d, J ¼ 8.7, 2H), 3.89 (s, 3H),
2.44 (s, 3H); 13C NMR (101 MHz, CDCl3)
(ppm): 159.0, 138.1, 136.4,
133.8, 129.6, 128.1, 126.7, 114.3, 55.4, 21.2.
d
10a. 1H NMR (400 MHz, CDCl3)
d (ppm): 7.73e7.67 (m, 4H), 7.60
(d, J ¼ 7.2, 2H), 7.49 (t, J ¼ 7.1, 2H), 7.46e7.39 (m, 1H); 13C NMR
[15] A. Fihri, M. Bouhrara, B. Nekoueishahraki, J.-M. Basset, V. Polshettiwar,
Nanocatalysts for Suzuki cross-coupling reactions, Chem. Soc. Rev. 40 (2011)
5181e5203.
(101 MHz, CDCl3)
127.3, 119.0, 111.0.
d (ppm): 145.7, 139.2, 132.7, 129.2, 128.8, 127.8,
11a. 1H NMR (400 MHz, CDCl3)
d
(ppm): 7.91 (dd, J ¼ 8.1, 1.5, 2H),
ꢀ
ꢀ
[16] M. Mora, C. Jimenez-Sanchidrian, J. Rafael Ruiz, Recent advances in the het-
erogeneous palladium-catalysed Suzuki cross-coupling reaction, Curr. Org.
Chem. 16 (2012) 1128e1150.
7.87 (d, J ¼ 8.2, 1H), 7.56e7.41 (m, 9H); 13C NMR (101 MHz, CDCl3)
d
(ppm): 140.9, 140.4, 133.9, 131.7, 130.2, 128.4, 127.8, 127.4, 127.1,
[17] K.H. Shaughnessy, Hydrophilic ligands and their application in aqueous-phase
metal-catalyzed reactions, Chem. Rev. 109 (2009) 643e710.
[18] K.H. Shaughnessy, R.B. DeVasher, Palladium-catalyzed cross-coupling in
aqueous media: recent progress and current applications, Curr. Org. Chem. 9
(2005) 585e604.
[19] M. Gholinejad, V. Karimkhani, I. Kim, Active palladium catalyst supported by
bulky diimine ligand catalyzed SuzukieMiyaura coupling reaction in water
under phosphane-free and low catalyst loading conditions, Appl. Organomet.
Chem. 28 (2014) 221e224.
[20] P. Conelly-Espinosa, R.A. Toscano, D. Morales-Morales, Synthesis and char-
acterization of hydrophilic theophylline base compounds and their use as li-
gands in the microwave assisted SuzukieMiyaura couplings of halopyridines
in water, Tetrahedron Lett. 55 (2014) 5841e5845.
126.2, 125.9, 125.5.
12a. 1H NMR (400 MHz, CDCl3)
d (ppm): 9.22 (s, 1H), 8.98 (s, 2H),
7.62e7.56 (m, 2H), 7.56e7.51 (m, 2H), 7.50e7.46 (m, 1H); 13C NMR
(101 MHz, CDCl3)
13a. 1H NMR (400 MHz, CDCl3)
7.48 (d, J ¼ 8.0, 2H), 7.33 (d, J ¼ 7.8, 2H), 2.43 (s, 3H).
14a. 1H NMR (400 MHz, CDCl3)
(ppm): 10.06 (s, 1H), 7.96 (d,
d
(ppm): 157.3, 155.0, 134.2, 129.6, 129.3, 127.2.
d
(ppm): 9.23 (s, 1H), 9.02 (s, 2H),
d
J ¼ 8.3, 2H), 7.76 (d, J ¼ 8.2, 2H), 7.66e7.61 (m, 2H), 7.49 (t, J ¼ 7.4,
2H), 7.42 (dd, J ¼ 8.4, 6.2, 1H); 13C NMR (101 MHz, CDCl3)
d (ppm):
192.1, 147.3, 139.8, 135.3, 130.4, 129.1, 128.6, 127.8, 127.5.
[21] P. Conelly-Espinosa, D. Morales-Morales, [Pd(HQS)2] (HQS
¼
8-
15a. 1H NMR (400 MHz, CDCl3)
d
(ppm): 8.37 (d, J ¼ 8.5, 2H), 7.95
(dd, J ¼ 7.9, 2.9, 2H), 7.79 (d, J ¼ 8.4, 1H), 7.68 (d, J ¼ 8.6, 2H),
7.57e7.43 (m, 4H); 13C NMR (101 MHz, CDCl3)
(ppm): 147.8, 147.3,
hydroxyquinoline-5-sulfonic acid) highly efficient catalyst for Suzu-
a
kieMiyaura cross couplings in water, Inorg. Chim. Acta 363 (2010)
1311e1315.
[22] M. Gholinejad, Palladium nanoparticles supported on agarose catalyzed
HeckeMatsuda and SuzukieMiyaura coupling reactions using aryl diazonium
salts, Appl. Organometal. Chem. 27 (2013) 19e22.
[23] H. Firouzabadi, N. Iranpoor, M. Gholinejad, 2-Aminophenyl diphenylphos-
phinite as an easily accessible ligand for heterogeneous palladium-catalyzed
SuzukieMiyaura reaction in water in the absence of any organic co-solvent,
J. Organomet. Chem. 695 (2010) 2093e2097.
[24] M. Sankar, N. Dimitratos, P.J. Miedziak, P.P. Wells, C.J. Kiely, G.J. Hutchings,
Designing bimetallic catalysts for a green and sustainable future, Chem. Soc.
Rev. 41 (2012) 8099e8139.
d
137.9, 133.9, 131.7, 131.1, 129.1, 128.7, 128.5, 128.4, 127.3, 126.9, 126.4,
125.5, 125.3, 123.7.
Acknowledgments
The authors are grateful to Institute for Advanced Studies in
Basic Sciences (IASBS) Research Council.
[25] J. Shi, On the synergetic catalytic effect in heterogeneous nanocomposite
Please cite this article in press as: M. Gholinejad, et al., Journal of Organometallic Chemistry (2015), http://dx.doi.org/10.1016/
j.jorganchem.2015.05.047

8
M. Gholinejad et al. / Journal of Organometallic Chemistry xxx (2015) 1e8
catalysts, Chem. Rev. 113 (2012) 2139e2181.
[34] X. Li, X. Zhao, S. Gao, S. Marques-Gonzalez, D.S. Yufit, J.A.K. Howard, P.J. Low,
Y. Zhao, N. Gan, Z. Guo, The structure and coordinative self-assembly of films
[26] B. Baruwati, D. Guin, S.V. Manorama, Pd on surface-modified nife2o4 nano-
particles: a magnetically recoverable catalyst for Suzuki and Heck reactions,
Org. Lett. 9 (2007) 5377e5380.
[27] D. Sengupta, J. Saha, G. De, B. Basu, Pd/Cu bimetallic nanoparticles embedded
in macroporous ion-exchange resins: an excellent heterogeneous catalyst for
the Sonogashira reaction, J. Mater. Chem. A 2 (2014) 3986e3992.
[28] R.N. Dhital, C. Kamonsatikul, E. Somsook, K. Bobuatong, M. Ehara, S. Karanjit,
H. Sakurai, Low-temperature carbonechlorine bond activation by bimetallic
gold/palladium alloy nanoclusters: an application to Ullmann coupling, J. Am.
Chem. Soc. 134 (2012) 20250e20253.
based on
a palladium compound of pyridyl-acetylene platinum and its
application in Suzuki and Heck coupling reactions, J. Mater. Chem. A 1 (2013)
9164e9172.
[35] X. Li, X. Zhao, J. Zhang, Y. Zhao, Assembly of a multilayer film and catalytic
application in Suzuki cross-coupling reaction based on synergistic effects of a
conjugated organometallic pyridyl Pt (C ≡ C)2 moiety with palladium, Chem.
Commun. 49 (2013) 10004e10006.
[36] J.P. Farr, F.E. Wood, A.L. Balch, Head-to-head and head-to-tail isomers of
binuclear complexes of platinum (I) and palladium (I) involving 2-(diphe-
[29] R.N. Dhital, C. Kamonsatikul, E. Somsook, H. Sakurai, Bimetallic gold-
palladium alloy nanoclusters: an effective catalyst for Ullmann coupling of
nylphosphino)pyridine as a bridging ligand, Inorg. Chem. 22 (1983)
3387e3393.
chloropyridines under ambient conditions, Catal. Sci. Technol.
3030e3035.
3
(2013)
[37] J.P. Farr, M.M. Olmstead, F. Wood, A.L. Balch, Formation and reactivity of some
heterobinuclear rhodium/platinum complexes with 2-(diphenylphosphino)
pyridine as a bridging ligand, J. Am. Chem. Soc. 105 (1983) 792e798.
[38] A. Maisonnat, J.P. Farr, A.L. Balch, Dinuclear palladium complexes of 2-
diphenylphosphinopyridine, Inorg. Chim. Acta 53 (1981) L217eL218.
[39] T. Ukai, H. Kawazura, Y. Ishii, J.J. Bonnet, J.A. Ibers, Chemistry of
dibenzylideneacetone-palladium(0) complexes: I. Novel tris(dibenzylidenea-
cetone)dipalladium(solvent) complexes and their reactions with quinones,
J. Organomet. Chem. 65 (1974) 253e266.
[30] M. Gholinejad, A. Aminianfar, Palladium nanoparticles supported on magnetic
copper ferrite nanoparticles: the synergistic effect of palladium and copper for
cyanation of aryl halides with K4[Fe(CN)6], J. Mol. Catal. A Chem. 397 (2015)
106e113.
[31] M. Gholinejad, J. Ahmadi, ChemPlusChem (2015), http://dx.doi.org/10.1002/
cplu.201500015.
[32] W. Yu, M.D. Porosoff, J.G. Chen, Review of Pt-based bimetallic catalysis: from
model surfaces to supported catalysts, Chem. Rev. 112 (2012) 5780e5817.
[33] R.B. Bedford, S.L. Hazelwood, D.A. Albisson, Platinum catalysts for Suzuki
biaryl coupling reactions, Organometallics 21 (2002) 2599e2600.
[40] V. Polshettiwar, A. Molnar, Silica-supported Pd catalysts for Heck coupling
reactions, Tetrahedron 63 (2007) 6949e6976.
Please cite this article in press as: M. Gholinejad, et al., Journal of Organometallic Chemistry (2015), http://dx.doi.org/10.1016/
j.jorganchem.2015.05.047