Palladium(II) tetrakis(4-N,N,N-trimethylammoniumphenylene)porphyrin supported on ion-exchange resins as efficient and reusable catalysts for C-C coupling reactions

Article abstract of DOI:10.1016/j.jorganchem.2014.02.006

In this research, the Heck and Suzuki reactions catalyzed by tetrakis(4-N,N,N-trimethylammoniumphenylene)porphyrinatopalladium(II) iodide, [Pd(TTMAPP)]I₄, immobilized on ion-exchange resins such as Dowex 50 WX8 and Amberlite IR-120 are reported. In this manner, first, tetrakis(4-N,N-dimethylaminophenylene)porphyrin was converted to tetrakis(4-N,N,N-trimethylammoniumphenylene)porphyrin iodide, [H ₂TTMAPP]I₄, with methyl iodide. Then this water soluble porphyrin was metalated by palladium(II) chloride and the [Pd(TTMAPP)]I ₄ was produced. This cationic palladium porphyrin was immobilized onto the ionic supports via electrostatic interactions. The catalysts, [Pd(TTMAPP)]@Dowex 50 WX8 and [Pd(TTMAPP)]@Amberlit IR-120, were characterized by FT-IR and diffuse reflectance UV-Vis spectroscopic methods, and scanning electron microscopy. These heterogeneous catalysts are thermally stable, oxygen insensitive, phosphine-free, air- and moisture-stable in the C-C coupling reactions and are reusable several times without significant loss of their catalytic activity.

Full text of DOI:10.1016/j.jorganchem.2014.02.006

Accepted Manuscript
Palladium(II) tetrakis(4-N,N,N-trimethylammoniumphenylene)porphyrin supported on
ion-exchange resins as efficient and reusable catalysts for C-C coupling reactions
Faranak Sadegh, Omid Bagheri, Majid Moghadam, Valiollah Mirkhani, Shahram
Tangestaninejad, Iraj Mohammadpoor-Baltork
PII:
S0022-328X(14)00085-0
10.1016/j.jorganchem.2014.02.006
JOM 18485
DOI:
Reference:
To appear in: Journal of Organometallic Chemistry
Received Date: 22 November 2013
Revised Date: 6 February 2014
Accepted Date: 13 February 2014
Please cite this article as: F. Sadegh, O. Bagheri, M. Moghadam, V. Mirkhani, S. Tangestaninejad,
I. Mohammadpoor-Baltork, Palladium(II) tetrakis(4-N,N,N-trimethylammoniumphenylene)porphyrin
supported on ion-exchange resins as efficient and reusable catalysts for C-C coupling reactions, Journal
of Organometallic Chemistry (2014), doi: 10.1016/j.jorganchem.2014.02.006.
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ACCEPTED MANUSCRIPT
Efficient Heck and Suzuki reactions catalyzed by tetrakis(4-N,N,N-
trimethylammuniumphenylene)porphyrinatopalladium(II) iodide,
[Pd(TTMAPP)]I4, immobilized on ion-exchange resins such as
Dowex 50 WX8 and Amberlite IR-120 are reported. These
heterogeneous catalysts are thermally stable, oxygen insensitive,
phosphine-free, air- and moisture-stable in the C-C coupling
reactions and are reusable several times.

ACCEPTED MANUSCRIPT
R
B(OH)2
X
[Pd(TTMAPP)]@Ion-Exchange Resin
R
DMF/H2O, K2CO3
∆
X=Cl, Br, I
R
X
[Pd(TTMAPP)]@Ion-Exchange Resin
R
DMF, K2CO3
∆
X=Cl, Br, I

ACCEPTED MANUSCRIPT
Palladium(II) tetrakis(4-N,N,N-
trimethylammoniumphenylene)porphyrin supported on ion-exchange
resins as efficient and reusable catalysts for C-C coupling reactions
Faranak Sadegh, Omid Bagheri, Majid Moghadam, Valiollah Mirkhani,* Shahram Tangestaninejad,
Iraj Mohammadpoor-Baltork
Department of Chemistry, Catalysis Division, University of Isfahan, Isfahan 81746-73441, Iran
Abstract- In this research, the Heck and Suzuki reactions catalyzed by tetrakis(4-N,N,N-
trimethylammoniumphenylene)porphyrinatopalladium(II) iodide, [Pd(TTMAPP)]I4, immobilized on
ion-exchange resins such as Dowex 50 WX8 and Amberlite IR-120 are reported. In this manner, first,
tetrakis(4-N,N-dimethylaminophenylene)porphyrin
was
converted
to
tetrakis(4-N,N,N-
trimethylammoniumphenylene)porphyrin iodide, [H2TTMAPP]I4, with methyl iodide. Then this water
soluble porphyrin was metallated by palladium(II) chloride and the [Pd(TTMAPP)]I4 was produced.
This cationic palladium porphyrin was immobilized onto the ionic supports via electrostatic
interactions. The catalysts, [Pd(TTMAPP)]@Dowex 50 WX8 and [Pd(TTMAPP)]@Amberlit IR-120,
were characterized by FT-IR and diffuse reflectance UV-Vis spectroscopic methods, and scanning
electron microscopy. These heterogeneous catalysts are thermally stable, oxygen insensitive,
phosphine-free, air- and moisture-stable in the C-C coupling reactions and are reusable several times
without significant loss of their catalytic activity.
Keywords: Palladium(II) porphyrin; Heterogeneous catalyst; Ion-exchange resins; C-C coupling
reactions; Aryl halides.
1. Introduction
Palladium(II) and palladium(IV) porphyrins have long been known specially for their photophysical
properties. The Pd-catalyzed synthetic methods are frequently applied to the synthesis and
Corresponding authors: Tel: +98-311-7932712; fax: +98-311-6689732; e-mail: moghadamm@sci.ui.ac.ir (M. Moghadam);
stanges@sci.ui.ac.ir (S. Tangestannejad)
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functionalization of porphyrins in these days and the fusion of Pd chemistry, and porphyrin chemistry
seems to be ready for entering a new dimension. Thus, a survey of recent studies on palladium and
porphyrins would be meaningful.
Recent studies have found that platinum(II) and palladium(II) porphyrins act as photosensitizers for
photochemical conversion and storage of solar-energy [2, 3], as potential molecular conductors [4] and
as photosensitizers for the cis to trans isomerization of stilbene [5]. These compounds also display
intense phosphorescence that has allowed their use as oxygen sensing probes [6].
The first synthesis of palladium tetraphenylporphyrin (PdTPP) was reported in 1959 [7]. Palladium
porphyrins typically are prepared by metalation of the free base porphyrin using PdCl2 in refluxing
acetic acid, [7] Pd(OAc)2 in refluxing benzonitrile, [8] or Pd(OAc)2 in CH2Cl2/MeOH at room
temperature.
Heck and cross-coupling reactions are two core chemistries that have provided a great impact on the
development of the new area of “metal-catalyzed organic syntheses”. Suzuki cross-coupling reaction
represents a powerful method for the C-C bond formation [9-14]. Construction of biaryl compounds via
the palladium-catalyzed Suzuki reaction is an interesting area in organic synthesis. The importance of
biaryl units as molecular components in pharmaceuticals, herbicides and natural products, as well as in
engineering materials such as conducting polymers, molecular wires and liquid crystals, has attracted
enormous interest [15-17]. These reactions represent an attractive alternative over other methods using
organometallics because organoboranes are air- and moisture-stable with relatively low toxicity.
Palladium-catalyzed coupling of aryl halides with alkenes, Heck cross-coupling reaction, is an
extremely valuable method for carbon-carbon bond formation too [18-21].
With various metals being employed in coupling reactions, palladium probably is the most versatile
metal in promoting or catalyzing reactions involving C–C and C–N bond formationdue to its excellent
catalytic efficiency in this type of reactions [22-25]. In recent years, various homogeneous palladium-
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phosphine catalysts [26-33] have been developed for the efficient cross-coupling reactions. However,
these catalysts usually need to be handled under inert atmosphere or dry conditions.
Palladium catalysts based on bulky, electron-donating alkylphosphines and N-heterocyclic carbenes
have been newly developed as ligands for carrying out these reactions of chloroarenes. This fascinating
field is still growing and continues to provide essential tools for precise synthesis of organic
compounds of practical significance [34-37].
It is also essential to find a precatalyst that remains stable even under the harsh conditions needed for
the activation and conversion of demanding substrates (aryl chlorides), but generates sufficient
amounts of coordinatively unsaturated Pd. Macrocyclic Pd complexes (e.g., phthalocyanines,
porphyrins, etc.) are characterized by a very high thermal and chemical stability, complete coordinative
saturation of the central atom, and a preference for the Pd(II) oxidation state. Although Pd-catalyzed
C–C coupling reactionshave widely been used to modify macrocyclic ligands like porphyrins,
porphyrazins or phthalocyanines [38-44], but only few examples of their application as C-C coupling
reaction catalystshave beenreported [45-46]. For example, Kostas et al. have used a water-soluble Pd
porphyrin as catalyst for the Suzuki reaction of aryl bromides with phenylboronic acid in water [47].
Wan et al. reported the first use of a Pd porphyrin for the Heck reaction of aryl iodides using ionic
liquids as reaction medium. The intact Pd porphyrin was detected by UV-Vis spectroscopy after the
reaction [48].
Ion-exchange resins are commercial products commonly available in the form of small beads (16-400
mesh, 1180-38 ꢀm diameter) or as membranes. Shape and size allow these materials to be easily and
quantitatively recovered by simple filtration or decantation. This is not the case for other powdered
materials often used as catalysts support (e.g., silica, zeolites, carbon, etc.). When the particle size is
about 1 ꢀm or less, they might not settle in the solution within a short time, and it would be very
difficult to collect them for recycling. The separation of the catalyst thus requires centrifugation or
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ultrafiltration. Very fine powders may also clog or poison the reactors or the autoclaves employed in
the catalytic experiments.
In continuation of our interest in the application of Pd based catalysts [49], here, the preparation,
characterization andcatalytic activity of a new thermally stable, oxygen insensitive, phosphine-free, air-
and moisture-stable, and reusable palladium porphyrin, [4-N,N,N-trimethylammoniumphenylene)-
porphyrinatopalladium(II) iodide, supported on Amberlit IR-120 and Dowex 50 WX8 in the C–C
coupling reactions via the Suzuki–Miyaura cross-coupling and Heck reactions are reported (Scheme 1).
2. Experimental
2.1. General Remarks
All the reagents were analytical grade and used without further purification. The chemicals used in this
work were purchased from Merck, Fluka and Sigma-Aldrich chemical companies.
1
The FT-IR spectra were recorded on a Jasco 6300 spectrophotometer. H NMR (400 and 100 MHz)
spectra were recorded on a Bruker-Avance 400 MHz spectrometer using DMSO-d6 as solvent.
Thermogravimetric analysis (TGA) was carried out on a Mettler TG50 instrument under air flow at a
uniform heating rate of 5 °Cmin-1 in the range 30-600 °C. The scanning electron micrographs were
taken on a Philips XL30 scanning electron microscope (SEM). The Pd content of the catalyst was
determined by a Perkin-Elmer ICP analysis.Substances were identified and quantified by gas
chromatography (GC) on an Agilent GC 6890 equipped with an 19096C006 80/100 WHP packed
column and a flame ionization detector (FID). UV-Vis spectra were recorded using a commercial
Shimadzu UV-160 spectrophotometer. Melting points were determined with a Stuart Scientific SMP2
apparatus. Diffuse reflectance ultraviolet-visible (DR UV-Vis) spectra were recorded on a JASCO, V-
670 spectrophotometer.
2.2. Synthesis of tetrakis(4-N,N,N-trimethylammoniumphenylene)porphyrinatopalladium(II) iodide,
[PdTTMAPP]I4
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First, the tetrakis(4-N,N-dimethylaminophenyleneporphyrin) was prepared in according to the classical
method of Adler and Longo [50] by the reaction of the p-N,N-diaminobenzaldehyde (0.3 mol) with
freshly distilled pyrrole (0.3 mol) in refluxing propionic acid (1000 ml) for 3 h (Yield 10%) [50]. FT-
IR spectra: 1676 (C=N), 1351 (C–N), 1607 and 1470 (C=C), 3309 and 1520 cm-1 (N–H pyrrole); UV-
Vis spectra in dimethylformamide (DMF): 416 (Soret band), 439, 513, 585 and 668 nm (Q bands).
Then, tetrakis(4-N,N-dimethylaminophenyleneporphyrin) (2.5 mmol) was converted to water soluble
tetrakis(4-N,N,N-trimethylammoniumphenyleneporphyrin) iodide, [H2TTMAPP]I4, with methyl iodide
(20 mmol) in DMF (100 ml) for 8 h at 100 °C under N2 atmosphere (Yield 70%)[51, 52]. FT-IR
spectra:1657 (C=N), 1351 (C–N), 1624 and 1472 (C=C), 3327 and 1557 cm-1 (N–H pyrrole); UV-Vis
spectra in DMF: 418 (Soret band), 513, 546, 588 and 643 nm (Q bands). Finally, tetrakis(4-N,N,N-
trimethylammoniumphenylene)porphyrinatopalladium(II) iodide, [PdTTMAPP]I4, was prepared by
refluxing of [H2TTMAPP]I4 (1 mmol) and Na2Pd2Cl6 (1 mmol) [prepared in situ from PdCl2 (1 mmol)
and NaCl (1 mmol) in (8 ml) deionizied water for 12 h] in water (100 ml) for 12 h (88% yield) [53]
1
(Scheme 2). In the H NMR spectrum of [Pd(TTMAPP)]I4 in DMSO-d6, the signal at -3 ppm
correspond to pyrrolic hydrogens in [H2TTMAPP]I4 was disappeared in [PdTTMAPP]I4 which
1
confirmed the synthesis and metallation of the ionic porphyrin. H NMR (400 MHz, DMSO-d6) for
[H2TTMAPP]I4: δ (ppm) = 8.87-8.40 (m, 24H, aromatic and β-hydrogens), 3.93 (s, 36H, CH3), -2.96
1
(s, 2H, pyrrolic hydrogens) ppm. H NMR (400 MHz, DMSO-d6) for [Pd(TTMAPP)]I4: δ (ppm) =
8.86-8.42 (m, 24H, aromatic and β-hydrogens), 3.93-3.92 (s, 36H, CH3).
2.3. Immobilization of [PdTTMAPP]I4 on Amberlit IR-120 and Dowex 50 WX8
The [Pd(TTMAPP)]@Dowex 50 WX8 and [Pd(TTMAPP)]@Amberlit IR-120 were prepared
according to the following procedure: Palladium(II) porphyrin (500 mg) was dissolved in minimum
volume of DMSO and a 1:1 acetone: water (50 ml) was added to this solution. The ion-exchange resin
(5 g) was added to this solution and heated at 80 °C for 24 h with stirring. At the end of the reaction,
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the catalyst was filtered, washed with DMSO, acetone and water, and dried under vaccum.The prepared
catalysts were characterized by ICP, thermogravimetric analysis (TGA) and DR UV-Vis spectroscopy.
3. Results and Discussion
3.1. Characterization of tetrakis(4-N,N,N-trimethylammoniumphenylene)porphyrinatopalladium(II)
iodide, [PdTTMAPP]I4, supported on Amberlit IR-120 and Dowex 50 WX8
1
The synthesis of [PdTTMAPP]I4 was monitored by UV-Vis and H NMR spectroscopy. UV-Vis
spectrum in DMSO: 416 (Soret band), and 521 and 585 nm (Q bands) (Fig.1).[PdTTMAPP]I4 has been
classified as hypsoporphyrins (irregular porphyrins) as the Soret and Q bands of this palladium(II)
porphyrin undergo a shift to shorter wavelength (a hypsochromic shift) with respect to
[H2TTMAPP]I4.The pyrrolic hydrogens signal in [H2TTMAPP]I4 (-3 ppm) was omitted in the 1H NMR
spectrum of [PdTTMAPP]I4 which confirmed the synthesis and metallation of the ionic porphyrin free
base (Fig. 2a and 2b).
-
Dowex 50 WX8 and Amberlit IR-120 are cation-exchange resins, which are contains the SO3 groupsin
their structures. [Pd(TTMAPP)]I4, which contains the trimethylphenylammunium groups at the meso-
positions of the porphyrin ligand was immobilized onto the Dowex 50 WX8 and Amberlit IR-120 via
electrostatic binding to prepare the [Pd(TTMAPP)]@Dowex 50 WX8 and [Pd(TTMAPP)]@Amberlite
IR-120 (Fig. 3). The ionic bonding of porphyrin with the ion-exchange resins was too strong in which
no palladium(II) porphyrin was eluted from the support with water, methanol, acetone and DMF.
The Pd content of the [Pd(TTMAPP)]@Dowex 50 WX8 was determined by ICP (0.115 mmol/g).
Thermogravimetric analysis was used to determine the thermal stability of the immobilized metal
complex [Pd(TTMAPP)]@Dowex 50 WX8. The free palladium(II) porphyrin shows a 23% weight loss
at temperatures below 225 °C (Fig. 4a). However, for the corresponding supported complex, there is a
continuous weight loss that extends above 257 °C, which confirms the thermal stability of the catalyst
after immobilization (Fig. 4b and 4c). The SEM images of the Dowex and [Pd(TTMAPP)]@Dowex 50
6

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WX8 showed that some of microspheres have been broken upon immobilization of Pd porphyrin on
Dowex 50 WX8 (Fig.5). In the reflectance spectrum of the [Pd(TTMAPP)]@Dowex 50 WX8 the Soret
band was appeared at 416 nm and the Q bands observed at 528 and 586 nm. These observations clearly
proved the presence of metalloporphyrin on the Dowex (Fig. 6a and 6b).
The Pd content of the [Pd(TTMAPP)]@Amberlit IR-120 was also determined by ICP (0.074 mmol/g).
In the thermogram of [Pd(TTMAPP)]@Amberlit IR-120 a less defined weight loss step and a weak
peak is observed at temperatures below 225 °C. However, for the corresponding immobilized complex,
a 5% weight loss was appeared. This behavior indicates the thermal stability of the catalyst upon
immobilization on to Amberlite (Fig. 7a and 7b). The same results were obtaiend for this catalyst by
SEM but the particles remain their microsphere nature (Fig. 8). In the DR UV-Vis spectrum of the
[Pd(TTMAPP)]@Amberlit IR-120 the Soret band was appeared at 415 nm and the Q bands observed at
527 and 585 nm. These observations clearly proved the presence of metalloporphyrin on the Amberlit
(Fig. 9a and 9b).
3.2. Suzuki–Miyaura cross-coupling of aryl halides with phenylboronic acid in the presence of
[Pd(TTMAPP)]@Dowex 50 WX8 and [Pd(TTMAPP)]@Amberlit IR-120
In the Suzuki C–C coupling reaction, for optimization of reaction parameters such as kind of base and
solvent, temperature and catalyst amount, the coupling of 4-iodoanisole (1 mmol) and phenylboronic
acid (1.5 mmol) under air was chosen as model reaction. The progress of the reaction was monitored by
GC. In the optimization of the catalyst amount, the best results were obtained using 0.0043 mmol of
catalyst (Table 1, entries1-5). This coupling reaction was found to be highly sensitive to the reaction
temperature. A reaction temperature of 95 °C was found to be optimal for the model reaction (Table 1,
entries 5-9). Then, the same reaction was carried out in different aqueous/organic media. The results
showed when the reaction was conducted in solvents like DMF and N-methylpyrrolidin-2-one (NMP),
the higher yields were produced. The use of tetrahydrofuran (THF), MeOH, EtOH and MeCN as
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solvent led to lower yields, and the lowest desired cross coupling product was observed in a non-polar
solvent such as toluene. Among the solvents examined, DMF/H2O (2:1) was proved to be the best
reaction medium (Table 1, entries 10-15). It seems that the water attack to phenylboronic acid to form
-
Ph-B(OH)3 and facilitates the elimination of B(OH)3.
The model reaction was carried out in the presence of different organic and inorganic bases such as
NEt3, Na3PO4and K2CO3. Amongst them, K2CO3 was found to be the most efficient base. Comparison
of inorganic bases utilized showed that carbonate base was more stable than the other one and an
organic base like Et3N was not as efficient as K2CO3 (Table 1, entries 16-18). Therefore, it was
concluded that the optimum reaction conditions involved 4-iodoanisole (1 mmol), phenylboronic acid
(1.5 mmol), K2CO3 (1.5 mmol) and [Pd(TTMAPP)@Dowex 50 WX8] (0.43 mol% Pd) in DMF/H2O
(2:1, 3 ml) at 95 °C under air (Table 1, entry 4).
When, Pd(TTMAPP)@Amberlit IR-120 was used as catalyst in the model reaction,the best results
were obtained in DMF/H2O (2:1, 3 ml) at 110 °C in the presence of 0.59 mol% Pd using K2CO3 as base
(Table 1).
The scope and generality of this method were investigated in the reaction of substituted aryl halides
with phenylboronic acid. As can be seen in Table 2, different aryl iodides, bromides and chlorides
containing electron-donating and electron-withdrawing substituents reacted efficiently with
phenylboronic acid under the optimized conditions to afford the desired cross-coupling products in
high yields. The experimental results showed that the electronic properties of the substituents on the
aromatic rings of starting materials had no significant influence on the reaction. As expected; aryl
iodides were found to be more reactive than aryl bromides and chlorides.
The catalytic activity of homogeneous [Pd(TTMAPP)]I4 was also investigated in the model reaction.
The results showed that in the reaction involved 4-iodoanisole (1 mmol), phenylboronic acid (1.5
mmol), K2CO3 (1.5 mmol) and [Pd(TTMAPP)]I4 (0.38 mol% Pd) in DMF/H2O (2:1, 3 ml) at 95 °C
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under air, the amount of desired product was 98% after 4 minutes (TOF 3868 h-1). The manin
disadvantage of homogeneous [Pd(TTMAPP)]I4 is its solubllity in the reaction mixture and can not be
recovered and reused.
1
All products were identified by comparison of their H NMR and IR spectral data and melting points
with those reported in the literature.
Comparison of the catalytic activity of both catalysts showed that [Pd(TTMAPP)]@Dowex 50 WX8 is
more reactive than [Pd(TTMAPP)]@Amberlit IR-120 (by comparison of the TOFs for aryl idides,
bromides and chlorides) and the reaction occures under milder conditions (lower temperature) (Table
3). This can be attributed to the different structurs of Dowex 50 WX8 and Amberlit IR-120. It is
important to note that Amberlit IR-120 is a cross-linked polymer (typically 0.5-20%) which controls
the resin porosity. The resin porosity affects some bulk properties of the resins which in turns affect the
resin properties in catalytic applications, i.e. swelling, capacity, equilibration rate, and selectivity.
3.3. Catalyst recovery and reuse
Easy catalyst separation and recycling insuccessive batch operations can greatly increase the efficiency
ofthe reaction. So, we studied the reusability of the present heterogeneous palladium catalysts in the
Suzuki coupling reaction of 4-iodoanisole and phenylboronic acid (Table 4). After completion of the
reactions, the catalysts were recovered by simple filtration and washed with DMF, H2O, diethyl ether
followed by acetone and dried under reduced pressure at 60 °C. The recovered catalysts were employed
in the next run with fresh 4-iodoanisole and phenylboronic acid. The catalysts showed slight loss in
their activity up to five reaction cycles. No catalysts leaching were observed after first two runs,
confirming the high stability of the heterogeneous catalysts under the reactions conditions. Moreover,
palladium leaching in these catalysts was also determined by ICP analysis. The nature of the recovered
catalysts was monitored by diffuse reflectance UV–Vis spectrophotometry. No change was observed in
the DR UV–Vis spectrum of the catalysts, which indicates the stability and robustness of the catalysts.
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The DR UV–Vis spectrum of recovered [Pd(TTMAPP)]@Dowex50 WX8 in Suzuki reaction is shown
in Fig. 10.
3.4. Heck cross-coupling of aryl halides with styrene in the presence of [Pd(TTMAPP)]@Dowex 50
WX8 and [Pd(TTMAPP)]@Amberlit IR-120
The successful application of [Pd(TTMAPP)]@Dowex 50 WX8 and [Pd(TTMAPP)]@Amberlit IR-
120 catalysts in the Suzuk-Miyaura coupling reaction, prompted us to explore their ability in the Heck
C-C coupling reaction.
First, the coupling of 4-iodoanisole (1 mmol) with styrene (2 mmol) in the presence of
[Pd(TTMAPP)]@Dowex 50 WX8 was studied as the model reaction under air and the reaction
conditions were systematically optimized. The results, which are summarized in Table 5, showed that
the highest yoeld was obtained using K2CO3 (2 mmol) as base and DMF (2 ml) as solvent in the
presence of 0.75 mol% Pd at 120 °C (Table 5, entry 4). Among the various bases studied, inorganic
bases such as K2CO3 and Na3PO4 were superior to NEt3 as an organic base. K2CO3 was found to be the
best base. Na3PO4 appeared to be a more moderate base than K2CO3 under these reaction conditions.
The effect of temperature on the activity of this catalyst was studied in the range 50–140 °C. As can be
seen in Table 5, by increasing the temperature to 120 °C, the yield is increased but increasing it from
120 to 140 °C did not influence the yield of reaction. When the reaction was performed at room
temperature, the reaction yield was significantly decreased. The effect of atalyst amount on the Heck
reaction was alsostudied. The results showed that the highest catalytic activity was observed with 0.745
mol% Pd. The effect of solvent on Heck coupling reaction was also examined in different polar and
non-polar solvents. Among different polar solvents, such as DMF, NMP, THF, MeOH, EtOH and
MeCN, the highest catalytic activity was observed in DMF. Non-polar solvents such as toluene were
not favorable for the Heck coupling reaction under these reaction conditions. Based on NMR spectra,
in all Heck coupling reactions, the trans-product was obtained with 100% selectivity.
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When the [Pd(TTMAPP)]@Amberlit IR-120 was used as catalyst in the Heck cross-coupling reaction,
the same results were obtained except for the catalyst amount in which the best results were detected in
the presence of 0.830 mol% Pd.
This protocol was applied for coupling of various aryl halides with styrene (Table 6). Styrene was
found to couple smoothly with iodobenzene and the corresponding product was obtained in excellent
yield (Table 6, entry 1). Less reactive aryl halides such as bromo and chlorobenzene were also
successfully coupled with styrene (Table 6, entries 2 and 3). Electron-donating groups such as methyl
and methoxy and electron-withdrawing groups such as nitro and Ac were successfully reacted with
styrene under the optimized reaction conditions. Sterically hindered 2-methyl-4-nitro-iodobenzene and
2-nitrobromobenzene were also reacted with styrene in good yields (Table 6, entries 7 and 11). 4-
Chloroacetophenone could also be converted to its corresponding coupling product in the presence of
this catalytic system (Table 6, entry 12). All the compounds were obtained exclusively with an (E)-
configuration.
When homogeneous [Pd(TTMAPP)]I4 (0.70 mol% Pd) was used as catalyst in the Heck reaction of 4-
iodoanisole (1 mmol) with styrene (2 mmol) using K2CO3 (2 mmol) as base in DMF (2 ml) at 120 °C
under air, the yield of desired product was 95% after 17 minutes (TOF 479 h-1).
All reactions were also repeated using [Pd(TTMAPP)]@Amberlit IR-120 as catalyst. As can be seen,
the corresponding coupled products were produced in good to excellent yields (Table 6). Comparison
of the obtained TOFs (for aryl idides, bromides and chlorides) of both catalysts showed that
[Pd(TTMAPP)]@Dowex 50 WX8 is more reactive than [Pd(TTMAPP)]@Amberlit IR-120 (Table 7).
The recyclability of these heterogeneous palladium catalysts was also investigated in the Heck cross-
coupling reaction of 4-iodoanisol with styrene. At the end of each reaction, the catalysts were separated
by simple filteration, washed with DMF, diethyl ether and acetone, and dried at reduced pressure at 60
°C. The recovered catalysts were reused in the next cycle with fresh 4-iodoanisol with styrene. The
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results showed that both catalysts could be reused five consecutive cycles without significant loss of
their catalytic activity (Table 8). The amounts of Pd leached were detected by ICP. As can be seen, no
catalyst was leached after first two catalytic cycles. No change was observed in the DR UV–Vis
spectrum of the catalysts, which indicates the stability and robustness of the catalysts (Fig. 11).
4. Conclusions
In summary, an example of Suzuki and Heck cross coupling reactions catalyzed by air stable, well
defined
and
recyclable
heterogeneous
[Pd(TTMAPP)]@Dowex
50
WX8
and
[Pd(TTMAPP)]@Amberlit IR-120 catalysts was described. The preparation of the catalysts from
commercially available supports, highly air and moisture stablility, good catalytic activity and high
reusability are noteworthy advantages of these catalysts in the C-C coupling reactions. These systems
were successfully applied for a wide variety of aryl halides in short reaction times.
Acknowledgements
The authors are grateful to the Research Council of the University of Isfahan for financial support of
this work.
References
[1] J. -I. Setsune, J. Porphyrins Phthalocyanines 8 (2004) 93-102.
[2] K. Kalyanasundaram, M. Neumann-Spallart, J. Phys. Chem.86 (1982) 5163-5169.
[3] P.J. Spellane, M. Gouterman, A. Antipas, S. Kim, Y.C. Liu, Inorg. Chem. 19 (1980) 386-391.
[4] E.M. McGhee, B.M. Hoffman, J.A. Ibers,Inorg. Chem. 30 (1991)2162-2165.
[5] J.A. Mercer-Smith, D.G. Whitten, J. Am. Chem. Soc.1 (1978) 2620-2625.
[6]B.W. Atwater, J. Fluoresc.2 (1992) 237-246.
[7]D.W. Thomas, A.E. Martell, J. Am. Chem. Soc. 81 (1959) 5111–5119.
[8]J.W. Buchler, in: Porphyrins and Metalloporphyrins,K. M. Smith, Ed.; Elsevier Scientific Publishing
Co., Amsterdam (1975) 157–231.
12

ACCEPTED MANUSCRIPT
[9] D. Alberico, M.E. Scott, M. Lautens, Chem. Rev.107 (2007) 174-238.
[10] N. Miyaura, A. Suzuki, Chem. Rev.95 (1995) 2457-2483.
[11] A. Suzuki, J. Organomet. Chem.57 (1999) 147-168.
[12] A. Suzuki, Angew. Chem. Int. Ed. 50 (2011) 6723-6737.
[13] G. C. Fortman, S. P. Nolan, Chem. Soc. Rev. 40 (2011) 5151-5169.
[14] F. S. Han, Chem. Soc. Rev. 42 (2013) 5270-5298.
[15] G. Bringmann, R. Walter, R. Weirich, Angew. Chem. Int.Ed. Engl. 44 (1990) 977-991.
[16] M. Kertesz, C. H. Choi, S. Yang, Chem. Rev.105 (2005) 3448-3481.
[17] B. Fabio, C. Adriano, R. Renzo, Synthesis (2004) 2419-2440.
[18] J. Board, Platinum Met. Rev.57 (2013) 234-258.
[19] X. Shang, Z. Q. Liu, Chem. Soc. Rev. 42 (2013) 3253-3260.
[20] H. J. Xu, Y. Q. Zhao, X. F. Zhou, J. Org. Chem. 76 (2011) 8036-8041.
[21] K. C. Nicolaou, P. G. Bulger, D.Sarlah, Angew. Chem. Int. Ed. 44 (2005)4442-4489.
[22] T.E. Barder, S.D. Walker, J.R. Martinelli, S.L. Buchwald, J. Am. Chem. Soc. 127(2005) 4685-
4696.
[23] M. Larhed, A. Hallberg, in: E. Negishi (Ed.), Handbook of Organopalladium Chemistry for
Organic Synthesis, vol. 1, Wiley-Interscience, New York, 2002,p. 1133.
[24] F. Diederich, P.J. Stang (Eds.), Metal-Catalyzed Cross-Coupling Reactions, Wiley-VCH,
Weinheim, 1998.
[25] M.R. Buchmeiser, T. Schareina, R. Kempe, K. Wurst, J. Organomet. Chem. 634(2001) 39-46.
[26] S. Demir, I. Özdemir, B. Çetinkaya, Appl. Organomet. Chem. 20 (2006)254-259.
[27] I. Özdemir, M. Yigit, E. Çetinkaya, B. Çetinkaya, Appl. Organomet. Chem. 20(2006) 187-192.
[28] B. Punji, G. Ganesamoorthy, M.S. Balakrishna, J. Mol. Catal. A: Chem. 259 (2006)78-83.
[29] R. B. Bedford, S.L. Welch, Chem. Commun. (2001) 129-130.
13

ACCEPTED MANUSCRIPT
[30] U. Christmann, R. Vilar, Angew. Chem. Int. Ed. 44 (2005) 366-374.
[31] R. Martin, S. L. Buchwald,Acc. Chem. Res.41 (2008) 1461-1473.
[32] M. Platon, R. Amardeil, L. Djakovitch, J. C. Hierso, Chem. Soc. Rev. 41 (2012) 3929-3968.
[33]C. Barnard, Platinum Met. Rev. 52 (2008) 38-45.
[34] B. P. Fors, D. A. Watson, M. R. Biscoe, S. L. Buchwald, J. Am. Chem. Soc. 130 (2008) 13552-
13554.
[35] E. A. B. Kantchev, C. J. O. Brien, M. G. Organ, Angew. Chem. Int. Ed. 46 (2007) 2768-2813.
[36] G. L. Duc, S. Meiries, S. P. Nolan, Organometallics.32 (2013) 7547-7551.
[37] G.C. Fortman, S. P. Nolan, Chem. Soc. Rev.40 (2011) 5151–5169.
[38] J. Sakamoto, A. D. Schluter, Eur. J. Org. Chem. 16 (2007) 2700-2712.
[39] M. Albrecht, R. Froehlich, Synlett 14 (2007) 2295-2297.
[40] H. Ali, N. Canchou, J. E. van Lier, Photochem. Photobiol. Sci. 8 (2009) 868-874.
[41] A. Goulomis, G. M. A. Rahman, J. Abel, G. de La Torre, P. Vazquez, L. Echegoyen, D. M. Guldi,
T. Torres, Aust. J. Chem. 61 (2008) 256-261.
[42] H. Ali, J. E. van Lier, Tetrahedron Lett. 50 (2009) 1113-1116.
[43] H. Ali, J. E. van Lier, Tetrahedron Lett. 50 (2009) 337-339.
[44] C. A. Barker, X. Zeng, S. Bettington, A. S. Batsanov, M. B. Bryce, A. Becby, Chem. Eur. J. 13
(2007) 6710-6717.
[45] C. Rçhlicha, K. Kçhler, Adv. Synth. Catal. 353 (2010) 2263-2274.
[46] C. Rçhlich, K. Kçhler, Chem. Eur. J. 16 (2010) 2363-2365.
[47] I. D. Kostas, A. G. Coutselos, G. Charalambidis, A. Skondra, Tetrahedron Lett. 48 (2007) 6688-
6691.
[48] Q. Wan, Y. Liu, Catal. Lett. 128 (2009) 487-492.
14

ACCEPTED MANUSCRIPT
[49] A. Landarani Isfahani,I. Mohammadpoor-Baltork,V. Mirkhani,A. R. Khosropour,M.
Moghadam,S. Tangestaninejad,R.Kia, Adv. Synth. Catal. 355 (2013)957–972.
[50] A. Adler, F. R. Longo, J. D. Finarelli, J. Goldmacher, J. Assour, L. Korsakoff, J. Org. Chem. 32
(1967) 476-477.
[51] M. Krishnamurthy, Indian. J. Chem. 15 (1977) 964-966.
[52] Y. Liu, H. J. Zhang, Y. Lu, Y. Q. Cai, X. L. Liu, Green Chem. 9 (2007) 1114-1119.
[53] R. Bernini, S. Cacchi, G. Fabrizi, G. Forte, F. Petrucci, A. Prastaro, S. Niembro, A. Shafird, A.
Vallribera, Green Chem. 12 (2010) 150–158.
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Fig. 1. The UV-Vis spectrum of [PdTTMAPP]I4 in DMSO: (a) 350-750 nm and (b) 450-750 nm
Fig. 2. The 1H NMR spectrum of: (a)[H2TTMAPP]I4 in DMSO-d6 and (b) Pd(TTMAPP)]I4 in DMSO-
d6
Fig. 3. The Pd(II) catalysts applied in this study: (a) [Pd(TTMAPP)]@Dowex 50 WX8 and (b)
[Pd(TTMAPP)]@Amberlit IR-120
Fig. 4. TG-DTG curve of: (a) [Pd(TTMAPP)]I4; (b) Dowex 50 WX8 and (c)
[Pd(TTMAPP)]@Dowex50 WX8
Fig. 5. SEM images of: a) Dowex 50 WX8 and b) [Pd(TTMAPP)]@Dowex 50 WX8
Fig. 6. The DR UV-Vis spectrum of: (a)Dowex 50 WX8 and (b) [Pd(TTMAPP)]@Dowex 50 WX8
Fig. 7. TG-DTG curve of: (a) Amberlit IR-120 and (b) [Pd(TTMAPP)]@Amberlit IR-120
Fig. 8. SEM image of: (a) Amberlit IR-120 and (b) [Pd(TTMAPP)]@Amberlit IR-120
Fig. 9. DR UV-Vis spectrum of: (a) Amberlit IR-120 and (b) [Pd(TTMAPP)]@Amberlit IR-120
Fig. 10. The DR UV-Vis spectrum of recovered [Pd(TTMAPP)]@Dowex50 WX8 in Suzuki reaction
Fig. 11. The DR UV-Vis spectrum of recovered [Pd(TTMAPP)]@Amberlit IR-120 in Heck reaction
16

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Table 1. Optimization of conditions in the Suzuki reaction of 4-iodoanisole and phenylboronic acid catalyzed by supported Pd porphyrin.a
OMe
I
B(OH)2
Supported Pd(II) porphyrin
Solvent, Base
T (oC)
MeO
Entry
Catalyst (mol% Pd)
Base
Solvent
T (°C)
Yield (%)b
[Pd(TTMAPP)]
[Pd(TTMAPP)]
[Pd(TTMAPP)]
[Pd(TTMAPP)]
[Pd(TTMAPP)]
[Pd(TTMAPP)]
@Amberlit IR-120
After 10 min
0
@Dowex 50 WX8
@Amberlit IR-120
@Dowex 50 WX8
@Amberlit IR-120 @Dowex 50 WX8
after 5 min
1
2
0
0
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
No Base
Na3PO4
NEt3
DMF/H2O (2:1)
DMF/H2O (2:1)
DMF/H2O (2:1)
DMF/H2O (2:1)
DMF/H2O (2:1)
DMF/H2O (2:1)
DMF/H2O (2:1)
DMF/H2O (2:1)
DMF/H2O (2:1)
MeOH/H2O (2:1)
EtOH/H2O (2:1)
MeCN/H2O (2:1)
Toluene/H2O (2:1)
NMP/H2O (2:1)
THF/H2O (2:1)
DMF/H2O (2:1)
DMF/H2O (2:1)
DMF/H2O (2:1)
95
95
110
0
0.055
0.35
0.43
0.75
0.43
0.43
0.43
0.43
0.43
0.43
0.43
0.43
0.43
0.43
0.43
0.43
0.43
0.22
0.46
0.59
0.75
0.59
0.59
0.59
0.59
0.59
0.59
0.59
0.59
0.59
0.59
0.59
0.59
0.59
110
30
81
97
97
20
62
77
98
55
70
62
40
82
44
4
25
73
97
98
22
64
70
96
53
73
65
38
81
47
2
3
95
110
4
95
110
5
95
110
6
r.t.
r.t.
7
50
50
8
70
95
9
120
Reflux
Reflux
Reflux
Reflux
Reflux
Reflux
95
130
10
11
12
13
14
15
16
17
18
Reflux
Reflux
Reflux
Reflux
Reflux
Reflux
110
95
110
70
35
73
32
95
110
aReaction conditions: 4-Iodoanisole (1 mmol), phenylboronic acid (1.5 mmol), base (1.5 mmol), solvent (3 ml) under air atmosphere.
bIsolated yield.
17

ACCEPTED MANUSCRIPT
Table 2. Suzuki cross-coupling reaction of aryl halides and phenylboronic acid catalyzed by
[Pd(TTMAPP)]@Dowex 50 WX8 and [Pd(TTMAPP)]@Amberlit IR-120.a
R
B(OH)2
X
[Pd(TTMAPP)]@Ion-Exchange Resin
R
DMF/H2O, K2CO3
∆
X=Cl, Br, I
[Pd(TTMAPP)]@Dowex 50 WX8b
[Pd(TTMAPP)]@Amberlit IR-120c
Entry
R
X
Time (min)
Yield (%)d
Time (min)
Yield (%)d
1
2
H
H
H
I
4
9
99
96
86
97
97
99
80
95
99
98
91
89
8
99
95
82
97
97
99
77
93
98
99
90
87
Br
Cl
I
15
26
9
3
18
4
4
4-Me
4-MeO
4-NO2
5
I
5
10
6
6
I
2
7
2-Me/4-NO2
4-MeO
4-NO2
I
6
12
19
13
12
20
19
8
Br
Br
Br
Br
Cl
12
8
9
10
11
12
4-Ac
8
2-NO2
15
12
4-Ac
aReaction conditions: Aryl halide (1 mmol), phenylboronic acid (1.5 mmol), K2CO3 (1.5 mmol), DMF/H2O
(2:1, 3 ml) under air.
b95 °C, Catalyst (0.43mol% Pd).
c110 °C, Catalyst (0.59 mol% Pd).
dIsolated yield.
18

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Table 3. Comparing of catalytic activity of supported Pd(II) porphyrin catalysts in the Suzuki reaction.a
Entry Aryl halide
T (°C)
95
Time (min)
Yield (%)b
TOF (h-1)
1
2
4-Iodoanisole
5
8
97c
2791
95
99c
1744
1-Bromo-4-nitrobenzene
3
4
5
6
4-Chloroacetophenone
4-Iodoanisole
95
12
10
13
19
89c
97d
98d
87d
1163
1017
782
110
110
110
1-Bromo-4-nitrobenzene
4-Chloroacetophenone
535
aReaction conditions: Aryl halide (1 mmol), phenylboronic acid (1.5 mmol), K2CO3 (1.5 mmol),
DMF/H2O (2:1, 3 ml).
bIsolated yield.
c[Pd(TTMAPP)]@Dowex 50 WX8 (0.43 mol% Pd)
d[Pd(TTMAPP)]@Amberlit IR-120 (0.59 mol% Pd)
19

ACCEPTED MANUSCRIPT
Table 4. Recycling and reuse of [Pd(TTMAPP)]@Dowex 50 WX8 and
[Pd(TTMAPP)]@Amberlit IR-120inthe Suzuki reaction.a
[Pd(TTMAPP)]@Dowex 50 WX8b
[Pd(TTMAPP)]@Amberlit IR-120c
Entry
Yield (%)d
Pd leached (%)e
Yield (%)d
Pd leached (%)e
1
2
3
4
5
97
97
96
96
94
1.35
97
96
95
95
93
1.23
1.16
1.06
-
-
-
-
-
-
aReaction conditions: 4-Iodoanisole (1 mmol), phenylboronic acid (1.5 mmol), K2CO3
(1.5 mmol), DMF/H2O (2:1, 3 ml) under air.
b95 °C, catalyst (0.43 mol% Pd), 5 min.
c110 °C, catalyst (0.59 mol% Pd), 10 min.
dIsolated yield.
eDetermined by ICP.
20

ACCEPTED MANUSCRIPT
Table 5.Optimization of the conditions in the Heck reaction of 4-iodoanisole and styrene catalyzed by supported Pd(II) porphyrin catalysts.a
OMe
I
[Pd(TTAAPP)]@Ion-Exchange Resins
Solvent, Base
MeO
T (oC)
Entry
Catalyst (mol% Pd)
Base
Solvent
T (°C)
Yield (%)b
[Pd(TTMAPP)]@Dowex [Pd(TTMAPP)]@Amberlit
[Pd(TTMAPP)]@Dowex 50
[Pd(TTMAPP)]@Amberlit
WX8
after 20 min
0
IR-120
after 25 min
0
50 WX8
0
IR-120
0
1
2
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
No Base
Na3PO4
NEt3
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
DMF
MeOH
EtOH
MeCN
Toluene
NMP
THF
120
120
0.33
0.43
0.75
0.86
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.37
0.74
0.83
0.93
0.83
0.83
0.83
0.83
0.83
0.83
0.83
0.83
0.83
0.83
0.83
0.83
0.83
25
67
95
97
20
58
70
98
48
66
60
37
80
44
2
24
66
89
91
16
56
72
91
46
65
60
33
80
42
3
3
120
4
120
5
120
6
r.t.
7
50
8
95
9
140
10
11
12
13
14
15
16
17
18
Reflux
Reflux
Reflux
Reflux
Reflux
Reflux
120
DMF
DMF
DMF
120
72
31
69
28
120
aReaction conditions: 4-Iodoanisole (1 mmol), styrene (2 mmol), base (2 mmol), solvent (2 ml) under air.
bIsolated yield.
21

ACCEPTED MANUSCRIPT
Table 6. Heck cross-coupling reactions of aryl halides with styrene using [Pd(TTMAPP)]@Dowex 50
WX8 and [Pd(TTMAPP)]@Amberlit IR-120.a
X
R
[Pd(TTMAPP)]@Ion-Exchange Resins
R
DMF (2.0 ml)
K2CO3 (2.0 mmol)
120 oC
X=Cl, Br, I
[Pd(TTMAPP)]@Dowex 50 WX8b [Pd(TTMAPP)]@Amberlit IR-120c
Entry
R
X
I
Time (min)
Yield (%)d
Time (min)
Yield (%)d
1
2
H
16
40
60
18
20
10
35
49
28
26
53
45
95
88
61
93
95
97
75
90
94
94
65
85
21
44
68
20
25
16
41
55
38
40
61
70
90
81
56
88
89
93
70
83
88
89
80
60
H
Br
Cl
I
3
H
4
4-Me
4-MeO
4-NO2
5
I
6
I
7
2-Me/4-NO2
4-MeO
4-NO2
4-Ac
I
8
Br
Br
Br
Br
Cl
9
10
11
12
2-NO2
4-Ac
aReaction conditions: Aryl halide (1 mmol), styrene (2 mmol), K2CO3 (2 mmol), DMF (2 ml), 120 °C
under air.
bCatalyst (0.75 mol% Pd).
cCatalyst (0.83 mol% Pd),
dIsolated yield.
22

ACCEPTED MANUSCRIPT
Table 7. Comparison of catalytic activity of [Pd(TTMAPP)]@Dowex 50 WX8 and
[Pd(TTMAPP)]@Amberlit IR-120 in the Heck reaction.
Entry Aryl Halide
T (°C)
120
Time (min)
Yield (%)b
95c
TOF (h-1)
400
1
20
28
4-Iodoanisole
2
120
94c
286
1-Bromo-4-nitrobenzene
3
4
5
6
120
120
120
120
45
25
38
70
85c
89d
88d
60d
178
289
190
103
4-Chloroacetophenone
4-Iodoanisole
1-Bromo-4-nitrobenzene
4-Chloroacetophenone
aReaction conditions: Aryl halide (1 mmol), phenylboronic acid (1.5 mmol), K2CO3 (1.5 mmol),
DMF/H2O (2:1, 3 ml).
bIsolated yield.
c[Pd(TTMAPP)]@Dowex 50 WX8 (0.75 mol% Pd)
d[Pd(TTMAPP)]@Amberlit IR-120 (0.83 mol% Pd)
23

ACCEPTED MANUSCRIPT
Table 8. Recycling and reuse of [Pd(TTMAPP)]@Dowex 50 WX8 and
[Pd(TTMAPP)]@Amberlit IR-120inoptimum model Suzuki reactions.a
[Pd(TTMAPP)]@Dowex 50 WX8b [Pd(TTMAPP)]@Amberlit IR-120c
Entry
Yield (%)d
Pd leached (%)e
Yield (%)d
Pd leached (%)e
1
2
3
4
5
95
93
92
92
89
0.15
89
87
86
86
86
0.10
0.10
0.08
-
-
-
-
-
-
aReaction conditions: 4-Iodoanisole (1 mmol), styrene (2 mmol), K2CO3 (2 mmol),
DMF (3 ml), 120 °C under air.
bCatalyst (0.75 mol% Pd), 20 min.
cCatalyst (0.83 mol% Pd), 25 min.
dIsolated yield.
eDetermined by ICP.
24

ACCEPTED MANUSCRIPT
Fig. 1. The UV-Vis spectrum of [PdTTMAPP]I4 in DMSO: (a) 350-750 nm and (b) 450-750 nm
25

ACCEPTED MANUSCRIPT
Fig. 2. The 1H NMR spectrum of: (a) [H2TTMAPP]I4 in DMSO-d6 and (b) [Pd(TTMAPP)]I4 in
DMSO-d6
26

ACCEPTED MANUSCRIPT
(A)
Me
Me
Me
N+
I-
N
N
N
Me
Me
-
Me N+
N+
R
R
SO3
Pd
I-
Me
Me
I-
Me
N
I-
N+
Me
Me
Me
Me
Me
(B)
Me
N+
I-
N
N
N
Me
Me
- Me N+
N+
R
R
SO3
Pd
I-
Me
Me
I-
Me
N
R= SO3Na
I-
N+
Me
Me
Me
Fig. 3. The Pd(II) catalysts applied in this study: (a) [Pd(TTMAPP)]@Dowex 50 WX8 and (b)
[Pd(TTMAPP)]@Amberlit IR-120
27