3,3'-((Arylmethylene)bis(4-methoxy-3,1-phenylene)) dipyridine derivatives as convenient ligands for Suzuki–Miyaura chemo- and homoselective cross-coupling reactions

Article abstract of DOI:10.1007/s13738-021-02373-y

Four novel N,N-bidentate triarylmethane-based ligands bearing β-pyridyl residues have been prepared and the catalytic activity of their in-situ generated palladium complexes were studied in the Suzuki–Miyaura cross-coupling reactions. Air and moisture stable 3,3'-((arylmethylene)bis(4-methoxy-3,1-phenylene))dipyridines L1-3 showed excellent activity in the Suzuki coupling reactions of aryl halides with aryl boronic acids under thermal and sonochemical reaction conditions. The described methodology provided good to high yields in short reaction times at ambient conditions. Moreover, it offered a straightforward way for Suzuki–Miyaura chemo- and homoselective cross-coupling of aryl halides with phenyl boronic acid. The structures of synthesized compounds were fully characterized by FT-IR, ¹H-NMR, ¹³C-NMR, and elemental analyses. The coordination of palladium acetate to nitrogen sites of L1 was also studied using FTIR spectroscopy, EDX analysis and SEM observations. Graphic abstract: The in-situ generated Pd-complexes of N,N-bidentate ligands L1-3 are described as robust and highly effective catalytic systems for the Suzuki cross-coupling of aryl halides with aryl boronic acids under thermal and sonochemical reaction conditions.[Figure not available: see fulltext.]

Full text of DOI:10.1007/s13738-021-02373-y

Journal of the Iranian Chemical Society
https://doi.org/10.1007/s13738-021-02373-y
ORIGINAL PAPER
3
,3'‑((Arylmethylene)bis(4‑methoxy‑3,1‑phenylene)) dipyridine
derivatives as convenient ligands for Suzuki–Miyaura chemo‑
and homoselective cross‑coupling reactions
Raziyeh Hosseini · Reza Ranjbar‑Karimi1 · Kazem Mohammadiannejad2
1
Received: 27 April 2021 / Accepted: 1 August 2021
©
Iranian Chemical Society 2021
Abstract
Four novel N,N-bidentate triarylmethane-based ligands bearing β-pyridyl residues have been prepared and the catalytic
activity of their in-situ generated palladium complexes were studied in the Suzuki–Miyaura cross-coupling reactions. Air
and moisture stable 3,3'-((arylmethylene)bis(4-methoxy-3,1-phenylene))dipyridines L1-3 showed excellent activity in the
Suzuki coupling reactions of aryl halides with aryl boronic acids under thermal and sonochemical reaction conditions. The
described methodology provided good to high yields in short reaction times at ambient conditions. Moreover, it oꢀered a
straightforward way for Suzuki–Miyaura chemo- and homoselective cross-coupling of aryl halides with phenyl boronic acid.
1
13
The structures of synthesized compounds were fully characterized by FT-IR, H-NMR, C-NMR, and elemental analyses.
The coordination of palladium acetate to nitrogen sites of L1 was also studied using FTIR spectroscopy, EDX analysis and
SEM observations.
Graphic abstract
The in-situ generated Pd-complexes of N,N-bidentate ligands L1-3 are described as robust and highly eꢀective catalytic
systems for the Suzuki cross-coupling of aryl halides with aryl boronic acids under thermal and sonochemical reaction
conditions.
Keywords Triarylmethanes · Palladium catalysis · N-donor ligands · Suzuki–Miyaura cross-coupling reactions · Chemo-
and homoselectivity
*
Reza Ranjbar-Karimi
r.ranjbarkarimi@vru.ac.ir
Extended author information available on the last page of the article
Vol.:(0
1
123456789)
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Journal of the Iranian Chemical Society
Introduction
as carbon [61, 62], silica [50, 63–68], magnetic nanoparti-
cles [50, 67–73], dendrimers [74], polymers [75, 76] and
polysaccharides [77] in SMC reactions, during these times,
has received enormous importance because they oꢀer sev-
eral advantages over their homogeneous counterparts includ-
ing operational simplicity, remarkable reusability, environ-
mental compatibility and exceptional stability [61–77]. In
recent years, neutral polydentate ligands containing N-donor
units, e.g., pyridine, pyrimidine, oxazoline, imidazole, pyra-
zole and triazole, have been employed to develop highly eꢁ-
cient catalysts for SMC reactions [78–87]. Li et al. have also
reported the SMC reactions of aryl boronic acids with aryl
halides or aryl dibromides mediated by PdCl2 and sodium
4-(1H-imidazo[4,5-f][1,10]phenanthrolin-1-yl)butane-1-sul-
fonate in water, and the corresponding coupling products
have obtained in good to excellent yields [88]. Triheteroar-
ylmethanes bearing pyridin-2-yl, N-methylimidazol-2-yl and
pyrazol-1-yl units have been employed as tripodal nitrogen
donor ligands for the synthesis of related palladium com-
plexes [89]. However, to the best of our knowledge, N,N-
bidentate triarylmethane-based ligands have not been yet
used in any Pd-catalyzed organic reactions. We recently
reported the synthesis of an organic molecule containing
two β-pyridyl residues linked to a triarylmethane (TRAM)
skeleton [90].
The facile and eꢁcient assembly of complex molecules is a
highly desired task in modern organic synthesis [1]. In this
context, the classical reactions such as Friedel–Crafts [2, 3],
Claisen–Schmidt condensation [4, 5], Diels–Alder [6], Wit-
tig [7] and Grignard reactions [8, 9] have been widely used
for shaping organic molecules. Over the past few decades,
cross-coupling reactions have also been continuously central
to research eꢀorts of organic chemistry and they have shown
an impressive ability to achieve transformations that were
not previously possible or only possible by means of multi-
ple steps of conventional methods [10, 11]. These reactions
utilize various organometallic reagents such as organoboron
(
Suzuki–Miyaura) [12–14], organomagnesium (Kumada or
Corriu) [14–16], organosilicon (Hiyama) [14, 17], organoz-
inc (Negishi) [14, 18, 19] and organotin (Stille) [14, 20] to
create new carbon–carbon bonds. Biaryls are privileged tem-
plates which are frequently found in natural products, func-
tional materials, polymers, liquid crystals, chiral reagents
and biologically active compounds. These fragments are also
employed as building block in organic synthesis and ligand
for homogeneous catalysis [21, 22]. The transition-metal-
catalyzed Suzuki–Miyaura coupling (SMC) reactions of aryl
boronic acids with aryl- or pseudo-halides have become truly
fundamental pathways for making biaryl scaꢀolds [23–30].
Prominent among these are Pd-catalyzed coupling reac-
tions which provide rapid and straightforward routes for the
The term of chemoselectivity is used to describe the pref-
erential reaction of a chemical reagent with one functional
group or reaction site in the presence of others [91]. Over the
last decades, there has been a growing interest in develop-
ing new reagents and catalysts to selectively aꢀord a single
product [92–97]. In addition, the concepts of chemo- and
homoselectivity have been elegantly investigated in various
reactions [98–106]. Traditionally, the chemoselectivity of
SMC reaction of substrates containing more than one halide
or pseudo-halide follows the established order of oxidative
addition I>Br≥OTs> >Cl [13, 107]. However, a reverse
chemoselectivity can be achieved by altering the catalyst
and/or ligand choice [108, 109].
2
construction of bond between two sp -hybridized carbons
[
31–37]. Palladium-catalyzed SMC reactions are typically
carried out using catalytic systems including phosphorous-
based ligands to assemble demanding molecule [13, 34,
3
8–44]. Recently, Ning et al. have employed PdCl adduct
2
of N-diphenylphosphanyl-2-aminopyridine for the highly
eꢁcient catalysis of SMC reaction of aryl chlorides with
aryl boronic acids [45]. Despite remarkable advancements,
the synthetic application of these catalytic systems has been
limited because phosphine ligands are toxic, expensive and
liable to air and moisture at elevated temperature [46, 47].
Thus, the development of highly active catalytic systems
incorporating inexpensive, readily accessible, as well as
air- and moisture-stable ligands is still in demand. In this
respect, a plethora of ligands containing coordinating atoms
such as carbon, nitrogen, oxygen, sulfur and selenium have
been employed in SMC reactions with considerable success
Sonochemistry is a new approach for promoting organic
reactions through transmission of ultrasound (US) energy.
Ultrasound irradiation utilizing synthetic protocols has
undergone explosive growth in the past few decades, because
they have been shown to substantially improve product
yields, increase reaction rates, reduce energy consumption
and raise product purity via diminishing or even eliminating
side reactions [110–112]. There are several reports avail-
able regarding the use of this unconventional methodology
to accelerate the Pd-catalyzed SMC reactions [112–116].
In continuation of our ongoing program on expanding
the synthetic applications of TRAMs [90, 117–120], and
application of ultrasonic irradiation in organic synthesis
[
48–59]. Zhang et al. have recently synthesized a series of
mono- and binuclear PdCl complexes of N,N′-disubstituted
2
imidazole-2-thiones, and several of them have shown good
to excellent catalytic activity toward Suzuki–Miyaura and
Cu-free Sonogashira coupling reactions [60]. Moreover, the
use of Pd-based complexes supported on various solids such
1
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Journal of the Iranian Chemical Society
[
121–123], we herein wish to report our eꢀorts on the use
Suzuki–Miyaura cross‑coupling reactions of aryl
halides under thermal and ultrasonic irradiation
conditions
of 3,3'-((arylmethylene)bis(4-methoxy-3,1-phenylene))dipy-
ridines L1–3 as air-stable N-donor ligands in Pd-catalyzed
SMC reaction of aryl halides with aryl boronic acids under
thermal and sonochemical reaction conditions.
Suzuki–Miyaura cross‑coupling reactions of aryl halides
under thermal conditions
Results and discussion
Having prepared the N,N-bidentate ligands L1–4, we aimed
to examine the catalytic activity of the in situ generated Pd-
complexes of ligands L1–4 for SMC reaction of aryl halides
with phenyl boronic acid. We commenced our exploration
by studying the Suzuki coupling reaction of 4-bromoaceto-
phenone 1b with phenyl boronic acid 4b as a model and the
results are listed in Table 1. Carrying out the model reaction
by taking 1b (1 mmol) and 4b (1.5 mmol) in 4 mL of DMF
Synthesis of N,N‑bidentate triarylmethane‑based
Ligands L1–4
Our attempts were initially directed toward the synthesis of
N,N-bidentate TRAM-based ligands L1–4. As depicted in
Scheme 1, brominated-triarylmethanes 3a–d were prepared
from the solvent-free reaction of 4-bromoanisole 1a with
aldehydes 2a–d in the presence of catalytic amount of silica
sulfuric acid (SSA). Precursors 3a–d were then submitted
to the Pd(PPh ) -catalyzed double-Suzuki coupling reaction
using 0.5 mol% of Pd(OAc) , 0.5 mol% of L1 and 2 mmol of
2
K CO at room temperature, furnished the coupling product
2
3
6a in 91% yield after 3 h (entry 1). Ligands L2 was also
found to be equally eꢀective in this coupling reaction (entry
2). Under the same conditions, the use of ligand L3 instead
of L1 aꢀorded an 87% yield of product 6a (entry 3), while
ligand L4 containing a bulky 1-naphthyl group on the TRAM
scaꢀold, showed a poor reactivity and its reaction provided
cross-coupled product 6a in only 37% yield (entry 4). Con-
sequently, TRAMs L1–3 were found to be mainly eꢀective
ligands for this substrate combination. We then turned our
3
4
with pyridine-3-bronic acid 4a, to aꢀord the corresponding
products L1–4 in good yields. Product L1 was also synthe-
sized via a two-step sequential SMC reaction of precursors
3
a and 5 with pyridine-3-bronic acid 4a in 76% yield. The
ligand L1 has already been described and matched with
bibliographic data [90]. The structures of new synthesized
ligands L2–4 were also conꢂrmed by NMR data.
Scheme 1. Reagents and conditions: (i) 1a (3 mmol), 2a–d (1 mmol),
SSA (200 mg), solvent-free, 70 °C, 25–60 min; (ii) 3a–d (1 mmol),
pyridine-3-bronic acid 4a (3.0 mmol), Pd(PPh ) (10 mol%), THF/
(5 mol%), THF (2 mL) and K CO (2 mL of 2 M solution), reꢃux,
2
3
12 h; (iv) 5 (1 mmol), pyridine-3-bronic acid 4a (1.5 mmol),
Pd(PPh ) (5 mol%), THF/DMF (2 mL, 1:1) and K CO (2 mL of
3
4
3 4
2
3
DMF (4 mL, 1:1) and K CO (3 mL of 2 M solution), reꢃux, 24 h;
2 M solution), reꢃux, 12 h
2
3
(
iii) 3a (1 mmol), pyridine-3-bronic acid 4a (1.5 mmol), Pd(PPh )
3 4
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Journal of the Iranian Chemical Society
attention toward the optimization of other reaction parame-
ters such as reaction medium, molar ratio of reactants, source
of palladium, catalyst loading, the ratio of [Pd] to ligand and
base. Decreasing the molar ratio of reactants to 1:1.4 and
then 1:1.2 resulted in lower yield of product 6a (entry 5),
while the use of higher molar ratios did not improve the
reaction yield (entry 6). Other palladium sources including
PdCl and PdCl (CH CN) were realized less eꢀective than
complex 7 (Scheme 2). Among the various tested solvent
systems, DMF was found to be the most eꢀective reaction
medium (entries 1 and 15–17). Of the various bases screened
(entries 1, 18 and 19), K CO provided the highest yield of
2
3
product 6a (entry 1), although K PO .3H O and Cs CO
3
4
2
2
3
were found to be eꢀective bases for this reaction (entry 18).
Additional studies indicated that the optimal loading for the
K CO was 2.0 mmol (entry 20). Based on the above results,
2
2
3
2
2
3
Pd(OAc) (entries 7 and 8). The eꢀect of catalyst loading on
the optimal reaction conditions were chosen as follows: 1b (1
2
the yield of product 6a was also studied and the highest yield
was obtained with 0.5 mol% of the catalyst (entry 1). Increas-
ing the catalyst loading from 0.5 to 0.6 and then 0.8 mol% did
not aꢀect the yield of 6a (entries 9 and 10), while applying
lower amounts of catalyst resulted in lower yields of coupling
product (entries 11 and 12). However, the reaction did not
take place in the absence of catalyst even after 6 h (entry 13).
Furthermore, the yield of reaction remained the same when
mmol), 4b (1.5 mmol), Pd(OAc) (0.5 mol%), L1 (0.5 mol%)
2
and K CO (2 mmol) in 4 mL of DMF at room temperature
2
3
(bolded line in Table 1, entry 1).
The formation of complex 7 was further studied using FT-IR
spectroscopy, EDX analysis and SEM observations. FT-IR
spectra of Pd-precursor, ligand L1 and complex 7 are given
in Scheme 3. The pure Pd(OAc) has three catachrestic peaks
2
−1
at 1605, 1429 and 696 cm corresponding to the stretching
frequencies of C=O, C–O and P–O, respectively (Scheme 3a).
In the IR spectrum of L1 (Scheme 3b), the vibrational band at
a 1:2 ratio of Pd(OAc) to L1 was used (entry 14). These
2
results suggest that coordination of ligand L1 to Pd(OAc)
2
−1
takes place from two nitrogen sites to form the chelating
1607 cm corresponds to the C=N stretching frequency. The
Table 1 Screening of the reaction conditions for the SMC reaction of 4-bromoacetophenone with phenylboronic acid.a
Entry
4b (mmol)
[Pd] Source (mol%)
L (mol%)
Yield (%)b
1
2
3
4
5
6
7
8
9
1.5
Pd(OAc) (0.5)
L1 (0.5)
L2 (0.5)
L3 (0.5)
L4 (0.5)
L1 (0.5)
L1 (0.5)
L1 (0.5)
L1 (0.5)
L1 (0.6)
L1 (0.8)
L1 (0.4)
L1 (0.2)
-
L1 (1.0)
L1 (0.5)
L1 (0.5)
L1 (0.5)
L1 (0.5)
L1 (0.5)
L1 (0.5)
91
2
1.5
Pd(OAc) (0.5)
90
2
1.5
1.5
1.4 (1.2)
1.6 (1.7)
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
Pd(OAc) (0.5)
87
37
82 (71)
91 (91)
71
77
91
91
2
Pd(OAc) (0.5)
2
Pd(OAc) (0.5)
2
Pd(OAc) (0.5)
2
PdCl (0.5)
2
PdCl (CH CN) (0.5)
2
3
2
Pd(OAc) (0.6)
2
10
11
12
13
14
15
16
17
18
19
20
Pd(OAc) (0.8)
2
Pd(OAc) (0.4)
74
58
2
c
Pd(OAc) (0.2)
2
d
No catalyst
n.d.
Pd(OAc) (0.5)
91
79
64
2
e
Pd(OAc) (0.5)
2
f
Pd(OAc) (0.5)
2
g
Pd(OAc) (0.5)
39
2
h
Pd(OAc) (0.5)
40
90
74
2
i
Pd(OAc) (0.5)
2
j
1.5
Pd(OAc) (0.5)
2
a
Unless otherwise stated, all the reactions were run in 4 mL of DMF using 1b (1 mmol) and K CO (2.0 mmol) under ambient conditions for
2
3
b
c
d
e
f
g
h
i
3
h. Isolated yield. Reaction time=6 h. n.d.=Not detected. Using Toluene. Using Dioxane. Using THF. Using 2.0 mmol of Et N.
3
j
Using 2.0 mmol of K PO .3H O or Cs CO . Using 1.5 mmol of K CO .
3
4
2
2
3
2
3
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Journal of the Iranian Chemical Society
−1
strong bands appeared at 1503 and 1474 cm correspond to
the C=C stretching frequencies. Likewise, the absorption band
−1
at 1249 cm is due to stretching vibration of C–O. On the
other hand, the IR spectrum of complex 7 (Scheme 3c) reveals
the characteristic peaks of pure substances at comparable wave
numbers. These results indicate that coordination takes place
between nitrogen atoms of L1 and Pd(OAc) .
2
The study of size and surface morphology of complex
7
was also performed by ꢂeld emission scanning electron
microscopy (FE-SEM). Scheme 4a shows the aggregation
of complex 7 particles. As can be seen in Scheme 4b, the
Scheme 2. In situ generation of the complex 7
Scheme 3. FT-IR spectrum of (a) Pd(OAc) , (b) ligand L1 and (c) complex 7
2
Scheme 4. SEM images of the complex 7
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Journal of the Iranian Chemical Society
prepared complex is composed of spherical particles with
the diameters in the range of 46–60 nm.
available than their aryl bromide counterparts [34, 44, 48,
51, 55, 124]. We focused later our attempts to explore the
The results obtained from the energy-dispersive X-ray
eꢁciency of Pd(OAc) /L1–3 catalytic systems in the SMC
2
(
EDX) of complex 7 are shown in Scheme 5, which clearly
reaction of aryl chlorides with phenyl boronic acid 4b.
Unfortunately, the reaction between 2,4-dinitrochloroben-
zene 8a with 4b did not take place under the above condi-
tions. After screening the reaction variables, the maximum
yields of product 6n was obtained via the combination of 8a
(1 mmol) with 4b (1.5 mmol) in the presence of in situ gen-
veriꢂed the existence of carbon, oxygen, nitrogen and pal-
ladium atoms in the structure of complex 7 and these are
additional indications for the attachment of Pd to ligand L1.
Likewise, the elemental mapping of complex 7 (Scheme 6)
reveals that elements C, O, N and Pd have been homogene-
ously dispersed within the texture of catalyst.
erated catalyst systems Pd(OAc) /L1–3 (2 mol%) in 4 mL
2
With the optimized conditions in hand (Table 1, entry
of DMF and 2 mmol of K CO at 100 °C under an atmos-
2
3
1
), the SMC reaction of various aryl bromides with phenyl
phere of argon (Table 3, entry 1). It is noteworthy to mention
that the use of 4b in amounts less than 1.5 mmol increases
the possibility of formation of the homocoupling product.
To expand the utility of these optimized conditions, aryl
chlorides 8b and 8c (containing nitro- and formyl electron-
withdrawing groups) were treated to 4b and their respective
coupling products 6q and 6r were achieved in good yields
after 8 h (Table 3, entries 4 and 5). Compound 6 s was also
obtained in 57 and 53% yields when a mixture of 3-chlo-
rophenol 8d and 4b was heated for 8 h in the presence of
ligands L1 and L3, respectively (Table 2, entry 6). Under the
optimized conditions, 2-chloropyridine 8e was coupled with
phenyl boronic acid 4b and the product 6t was obtained in
only 35% yield (Table 3, entry 8). However, 2-chloropyra-
zine 8f plus phenyl boronic acid gave a moderate yield of
coupling product 6u (Table 3, entry 9). These SMC reac-
tions can be described by a plausible Pd(II)/Pd(IV) catalytic
cycle which comprises some fundamental steps as shown in
Scheme 7 [125]. First, the oxidative addition of aryl halides
boronic acid 4b in the presence of ligands L1–3 was car-
ried out, and the results are illustrated in Table 2. This reac-
tion took place eꢁciently for electron-poor aryl bromides
such as 4-bromonitrobenzene 1c, 4-bromobenzaldehyde 1d,
2
-bromobenzaldehyde 1e, as well as 4-bromobenzonitrile
f, and coupling products 6d–g were provided in good to
1
high yields under mild reaction conditions (entries 4–7).
The SMC reaction for electronically neutral aryl bromides
like bromobenzene 1 g and 4-bromotoluene 1 h aꢀorded
the corresponding products 6 h and 6i in 63 and 74% yields,
respectively (entries 8 and 9). 4-Bromoanisole 1a as an
electron-rich substate was smoothly coupled with 4b and
the expected product 6j furnished in 56% yield (entry 10).
Likewise, thiophene 1i furnished the coupling product 6 k
in a moderate yield after 6 h (entry 11).
In recent years, a great deal of attention has been paid to
the use of aryl chlorides as coupling partner of aryl boronic
acid derivatives, since they are cheaper and more readily
Scheme 5. EDX spectrum of
the complex 7
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Journal of the Iranian Chemical Society
Scheme 6. Elemental mapping of the complex 7
to N,N-bidentate Pd(II) complex provides intermediate cis
(0.5 mol%), L1 (0.5 mol%) and K CO (2 mmol) in 4 mL of
2
3
(
1). This Pd(IV) species is then isomerized to intermediate
DMF was sonicated at ambient conditions under two diꢀer-
ent modes. Product 6a was isolated in 82% yield when the
reaction mixture was irradiated for 6 min using the continu-
ous ultrasound (C-US) mode. On the contrary, irradiation of
the reaction mixture with the pulsed ultrasound (P-US) mode
for 15 min provided compound 6a in 93% yield. The eꢀect of
US irradiation amplitude on this reaction was also screened
and a full conversion of starting material was obtained at
trans (1) because it is more stable than the cis form. The
replacement of X by carbonate, followed by a transmetala-
tion step including the activated organoboronic acid aꢀords
intermediate trans (2). The intermediate cis (2) is produced
via the second isomerization which in turn is subjected to a
reductive elimination to aꢀord the coupling product 6 and
regenerate the original Pd(II) complex.
3
0% amplitude. It is worthy of note that the temperature
Suzuki–Miyaura cross‑coupling reactions of aryl halides
under ultrasonic irradiation conditions
of reaction mixture reached 36 °C at the end of reaction.
Performing this reaction using ligands L2 and L3 achieved
comparable yields of 6a, but the reaction in the presence of
L4 gave 6a in 38% yield even after 30 min (Table 2, entry
1). We hence preferred to run the SMC reactions of aryl
bromides with aryl boronic acids using milder P-US method
and in the presence of ligands L1–3. Accordingly, a variety
of aryl bromides were coupled with aryl boronic acids 4b–d
Encouraged by the above results, we therefore attempted to
evaluate the utility of Pd(OAc) /L1–3 catalytic systems in
2
the SMC reactions of aryl halides with aryl boronic acids
under ultrasound irradiation. In this respective, a mixture
of aryl bromide 1b (1 mmol), 4b (1.5 mmol), Pd(OAc)
2
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Journal of the Iranian Chemical Society
Table 2 Suzuki–Miyaura cross-coupling reaction of aryl bromides with aryl boronic acids in the presence of Pd(OAc) /L1-4
2
a
Ambient conditions reaction conditions: aryl bromide 1 (1 mmol), phenyl boronic acid 4b (1.5 mmol), DMF (4 mL), Pd(OAc) (0.5 mol%), L
2
b
(
0.5 mol%), K CO (2 mmol), rt. Ultrasonic irradiation conditions: aryl bromide 1 (1 mmol), aryl boronic acid 4 (1.5 mmol), DMF (4 mL),
2
3
c
Pd(OAc) (0.5 mol%), L (0.5 mol%), K CO (2 mmol), amplitude (30%), P-US mode (the probe is on for 10 Sec / The probe is oꢀ for 10 Sec).
2
2
3
Isolated yield
1
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Journal of the Iranian Chemical Society
and their respective products 6a–k were isolated in higher
yields and dramatically shortened reaction times compared
to the thermal conditions (Table 2, entries 1–11). Double
SMC reaction of 1,4-dibromobenzene 1j with 4b in the pres-
ence of ligands L1 and L2 furnished p-terphenyl 6 l in 84
and 87% yields after 20 min, respectively (Table 2, entry 12).
Given the diꢀerence in reactivity of bromide and chloride,
the bromide group in 1-bromo-2-chlorobenzene 1 k was
selectively coupled with 4b and compound 6 m was isolated
in 86% yield under such mild reaction conditions (Table 2,
entry 13). We suppose that these signiꢂcant merits of US
irradiation can be mainly attributed to more eꢀective mass
transfer compared to magnetically stirred way. Expectedly,
aryl chlorides did not react with 4b under such mild reaction
conditions. To examine the eꢁciency of US irradiation on
these reactions, we set a series of experiments to achieve the
best conditions for combination of 2,4-dinitrophenyl chlo-
ride 8a with 4b as a model. The highest yield of coupling
product 6n was obtained when a mixture of 8a (1 mmol), 4b
4-bromobenzaldehyde 1d (1 mmol), 4-chlorobenzaldehyde
8j (1 mmol) and 4b (1.5 mmol) was sonicated. The results
showed that 1d reacts exclusively with 4b, and substrate
8j remains intact in this reaction. Under similar conditions,
an excellent halogen chemoselectivity was observed in the
reaction of 1-bromo-2-chlorobenzene 1 k with 4b. Irradia-
tion of a mixture of 1 k (1 mmol) and 4b (1.5 mmol or
even 3.0 mmol) applying the P-US or C-US mode aꢀorded
compound 6 m as the sole product (Scheme 8). Finally,
2,4,6-trichloropyrimidine 8 h and 4,7-dichloroquinoline 8i
were chosen to check the homoselectivity of the presented
method for SMC reaction of aryl chlorides (Table 3). Treat-
ment of 8 h (1 mmol) with 4b (1.5 mmol) aꢀorded prod-
ucts 6v and 6×in 51 and 36% yields, respectively. In fact,
substrate 8 h revealed a moderate homoselectivity for chlo-
rines at C-2 and C-4 positions. However, when a mixture
of 8i (1 mmol) and 4b (1.5 mmol) was irradiated under the
optimized conditions, a remarkable homoselectivity was
observed between two C–Cl reaction sites and compounds
6y was obtained in yield of 83% (Scheme 9). Compounds
6y’ and 6y” were also obtained as an unseparable mixture,
in overall yield of 10%.
(
1.5 mmol), Pd(OAc) (2 mol%), L1–3 (2 mol%) and K CO
2
2
3
(
2 mmol) in 4 mL of DMF was sonicated for 15 min at 100%
amplitude of ultrasound using the C-US mode. The ꢂnal
temperature of the reaction mixture was recorded as 64 °C.
However, the controlled experiment revealed that this reac-
tion did not take place signiꢂcantly under thermal conditions
at 64 °C. Eventually, a variety of aryl chloride substrates
Conclusion
8
a–i were submitted to the reaction with 4b under these
In conclusion, we designed and synthesized a novel series
of N,N-bidentate TRAM-based ligands L1–4. Exploring the
in situ generated palladium complexes of ligands L1–4 for
the SMC reaction of aryl halides revealed that 3,3'-((aryl-
methylene)bis(4-methoxy-3,1-phenylene))dipyridines L1–3
are aꢀordable and robust ligands for the Pd-catalyzed SMC
reactions of aryl boronic acids with several aryl bromides
and chlorides both under thermal and US irradiation condi-
tions. Furthermore, air- and moisture-stable ligands L1–3
are suggested as useful alternatives to the commonly used
phosphine ligands. The described methodology also pro-
vided remarkable chemo- and homoselectivity in SMC reac-
tions of aryl bromides and chlorides with phenyl boronic
acid mediated by Pd(OAc)2/L1 catalytic system. Moreover,
the coordination of palladium acetate to nitrogen sites of L1
was conꢂrmed through FT-IR spectroscopy, EDX analysis
and SEM observations.
optimized conditions and their respective coupling products
were achieved in 38–86% yields (Table 3, entries 1–6, 8–10
and 12). US-assisted reaction of substrate 8 h with 4b pro-
vided coupling products 6w and 6×in 51 and 36% yields,
respectively (Table 3, entry 11). However, substrate 1 k was
not activated enough to react with twofold amounts of 4b
to yield o-terphenyl 6 m”, and even after 20 min of US
irradiation, compound 6 m was isolated as the sole coupling
product in 90% yield (Table 3, entry 7). The improvement of
the yields and acceleration of the reactions is probably due
to the cavitation eꢀect of ultrasound irradiation. In other
words, the formation, expansion and implosive collapse of
bubbles in the reaction mixture produce a microenvironment
in which the reactions occur more eꢁciently.
Chemo‑ and homoselectivity
It is of interest that our catalytic system provided the che-
moselectivity (using aryl halides bearing diꢀerent halides)
and homoselectivity (using aryl halides bearing similar hal-
ides) in SMC reaction of aryl halides with phenyl boronic
acid. We ꢂrst examined the chemoselectivity for the Suzuki
coupling of aryl bromides with 4b under optimized con-
ditions as presented in Table 2. Accordingly, a mixture of
Experimental details
General information
The melting points were obtained with a Stuart SMP2 appa-
ratus and are uncorrected. NMR spectra were recorded on a
Varian UNITY Inova 500 MHz spectrometer. FT-IR spectra
1
3

Journal of the Iranian Chemical Society
Table 3 Suzuki–Miyaura cross-coupling reaction of aryl chlorides with aryl boronic acids in the presence of Pd(OAc) /L1-3
2
a
Thermal reaction conditions: aryl chloride 1 (1 mmol), phenyl boronic acid 4b (1.5 mmol), DMF (4 mL), Pd(OAc) (2 mol%), L (2 mol%),
2
b
K CO (2 mmol), 100 °C, and under argon. Ultrasonic irradiation conditions: aryl bromide 1 (1 mmol), aryl boronic acid 4b (1.5 mmol), DMF
2
3
c
(
4 mL), Pd(OAc) (2 mol%), L (2 mol%), K CO (2 mmol), amplitude (100%), and C-US mode. Isolated yield
2 2 3
1
3

Journal of the Iranian Chemical Society
Scheme 7. Plausible catalytic
cycle for SMC reactions in
the presence of Pd(OAc) /L
2
complex
obtained commercially and were used without further puriꢂ-
cation. The solvents used as reaction mediums were puriꢂed
and dried according to standard procedures. The thermally
reactions of aryl chlorides with phenyl boronic acid were
conducted in dried solvents, oven-dried apparatus, under an
atmosphere of dry argon.
General procedures
General procedure for the synthesis of triarylmethane 3a–d
(Scheme 1)
Scheme 8. Reagents and conditions: (i) DMF (4 mL), Pd(OAc)
2
(
0.5 mol%), L1 (0.5 mol%), K CO (2 mmol), amplitude (30%),
2 3
P-US mode (the probe is on for 10 Sec / The probe is oꢀ for 10 Sec);
Silica sulfuric acid (SSA) was prepared according to the
literature [126]. Triarylmethanes 3a–d were prepared in
accordance with our previous method [127]. A 25-ml round-
bottom ꢃask equipped with a magnetic stir bar is loaded
with 4-bromoanisole 1a (3 mmol), corresponding aldehyde
2a–d (1 mmol) and silica sulfuric acid (SSA, 200 mg) and
the stirred mixture was heated at 70 °C for 25–60 min. The
progress of the reaction was monitored by TLC (eluent:
n-Hexane/EtOAc 10:4). Upon completion of the reaction,
the resultant mixture was cooled to room temperature and
(
(
ii) DMF (4 mL), Pd(OAc) (1.0 mol%), L1 (1.0 mol%), K CO
2
2
3
4 mmol), amplitude (100%) and C-US mode
were acquired over the range of 400–4000 cm−1 using a
Nicolet-Impact 400D spectrophotometer from KBr pellets.
Elemental analyses were performed on a LECO CHNS-932
analyzer instrument. TLC analyses were performed on pre-
coated silica gel F-254 plates and visualized under UV light.
All chemicals and solvents, unless otherwise stated, were
1
3

Journal of the Iranian Chemical Society
Scheme 9. Reagents and
conditions: (i) DMF (4 mL),
Pd(OAc) (2 mol%), L1
2
(
2 mol%), K CO (2 mmol),
2
3
amplitude (100%) and C-US
mode
washed twice with absolute EtOH (5 mL). After separation
of catalyst by simple ꢂltration, the crude was puriꢂed by
recrystallization from EtOH to aꢀord the corresponding
TRAMs 3a–d. The products 3a has already been described
and matched with bibliographic data [90].
C, 49.73; H, 3.38; N, 2.76. Found: C, 49.16; H, 3.31; N,
2.67.
1-(Bis(5-bromo-2-methoxyphenyl)methyl)naphtha-
lene (3d) White solid. Yield 34%. Mp 157–160 °C. 1H
NMR (500 MHz, CDCl3) δ 7.84–7.88 (m, 2H), 7.75 (d,
J = 8.2 Hz, 1H), 7.32–7.46 (m, 5H), 6.91–6.94 (m, 1H),
6.85 (d, J = 2.6 Hz, 2H), 6.80 (bs, 1H, Ar3CH), 6.80 (d,
J=8.7 Hz, 2H), 3.68 (s, 6H, OMe). 13C NMR (125 MHz,
CDCl3) δ 156.17, 138.54, 134.07, 133.98, 132.63, 131.84,
130.55, 128.66, 127.33, 126.08, 125.98, 125.39, 125.15,
124.00, 112.91, 112.06, 55.94, 39.30. FT-IR (KBr) νmax
2932, 2839, 1596, 1516, 1483, 1460, 1396, 1344, 1281,
1244, 1220 cm−1. Anal. Calcd for C25H20Br2O2: C, 58.62;
H, 3.94. Found: C, 58.13; H, 3.87.
2
,2'-(Phenylmethylene)bis(4-bromo-1-methoxyben-
zene) (3a) [90] White solid. Yield 94%. Mp 148–150 °C.
H NMR (500 MHz, CDCl3) δ 7.32 (dd, J1 = 8.5 Hz,
J2 = 2.5 Hz, 2H), 7.27–7.30 (m, 2H), 7.20–7.26 (m, 1H),
.04 (d, J =7.6 Hz, 2H), 6.87 (d, J = 2.5 Hz, 2H), 6.74 (d,
J = 8.7 Hz, 2H), 6.06 (s, 1H, Ar3CH), 3.68 (s, 6H, OMe).
1
7
1
1
5
1
3C NMR (125 MHz, CDCl3) δ 156.27, 141.90, 134.29,
32.43, 130.35, 129.18, 128.26, 126.36, 112.77, 112.54,
5.86, 43.43. FT-IR (KBr) νmax 2935, 1484, 1461, 1244,
115, 913, 743, 450 cm−1. Anal. Calcd for C21H18Br2O2:
C, 54.57; H, 3.93. Found: C, 54.49; H, 3.90.
,2'-(p-Tolylmethylene)bis(4-bromo-1-methoxy-
benzene) (3b) White solid. Yield 92%. Mp 149–152 °C.
H NMR (500 MHz, CDCl3) δ 7.31 (dd, J1 = 8.7 Hz,
J2=2.5 Hz, 2H), 7.07 (d, J=7.5 Hz, 2H), 6.92 (d, J=8.1 Hz,
General procedure for the synthesis of ligands L1–4
(Scheme 1)
2
1
N,N-bidentate ligands L1–4 were prepared following the
modiꢂed version of our reported method [90]. To an oven-
dried two-necked ꢃask equipped with a condenser and a
stir bar were added Pd(PPh3)4 (10 mol%), TRAM 3a–d
(1 mmol) and pyridine-3-bronic acid 4a (3.0 mmol). After
applying an atmosphere of argon, degassed THF (2 mL),
DMF (2 mL) and K2CO3 (3 mL of 2 M solution) were
added. The resultant mixture was stirred under reꢃux con-
ditions for 24 h, cooled to room temperature, ꢂltered through
a Celite, and volatiles were evaporated under reduced pres-
sure. The resulting crude was puriꢂed by performing a ꢃash
chromatography on silica gel (eluent: petroleum ether/meth-
anol 10:1) to obtain the pure ligands L1–4. The ligand L1
has already been described and matched with bibliographic
data [90].
2
H), 6.88 (d, J=2.6 Hz, 2H), 6.02 (s, 1H, Ar3CH), 6.73 (d,
J=8.8 Hz, 2H), 3.67 (s, 6H, OMe), 2.33 (s, 3H, Me). 13C
NMR (125 MHz, CDCl3) δ 156.30, 138.73, 135.78, 134.64,
1
4
1
32.40, 130.25, 129.30, 128.98, 112.78, 112.58, 55.90,
3.03, 20.99. FT-IR (KBr) νmax 2935, 1484, 1461, 1244,
115, 913, 743, 450 cm−1. Anal. Calcd for C22H20Br2O2:
C, 55.49; H, 4.23. Found: C, 55.34; H, 4.19.
2
,2'-((3-Nitrophenyl)methylene)bis(4-bromo-1-meth-
oxybenzene) (3c) White solid. Yield 95%. Mp 147–149 °C.
H NMR (500 MHz, CDCl3) δ 8.08–8.11 (m, 1H), 7.92
t, J = 2.0 Hz, 1H), 7.44 (t, J = 7.9 Hz, 1H), 7.36 (dd,
J1=8.7 Hz, J2=2.5 Hz, 2H), 7.34 (d, J=7.7 Hz, 1H), 6.72
1
(
(
d, J = 2.5 Hz, 2H), 6.78 (d, J = 9.0 Hz, 2H), 6.12 (s, 1H,
Ar3CH), 3.69 (s, 6H, OMe). 13C NMR (125 MHz, CDCl3)
δ 156.13, 148.41, 144.69, 135.00, 132.41, 132.34, 131.12,
3,3'-((Phenylmethylene)bis(4-methoxy-3,1-phe-
nylene))dipyridine (L1) [90] White solid. Yield 73%.
Mp 190–192 °C. 1H NMR (500 MHz, CDCl3) δ 8.66 (d,
J = 2.3 Hz, 2H), 8.47 (dd, J1 = 4.8 Hz, J2 = 1.6 Hz, 2H),
7.66–7.69 (m, 2H), 7.46 (dd, J1=8.4 Hz, J2=2.4 Hz, 2H),
1
29.07, 123.94, 121.62, 112.92, 112.67, 55.79, 43.43. FT-IR
(
KBr) νmax 3068, 3010, 2937, 2905, 2838, 2530, 2040,
858, 1705, 1589 cm−1. Anal. Calcd for C21H17Br2NO4:
1
1
3

Journal of the Iranian Chemical Society
7
.20–7.31 (d, J=2.3 Hz, 2H), 6.99 (d, J=8.5 Hz, 2H), 6.26
125.14, 124.31, 123.43, 111.36, 55.92, 39.64. FT-IR (KBr)
νmax 3027, 2931, 2836, 1607, 1503, 1474, 1288, 1249,
1113, 1065, 1022, 801, 751, 712 cm−1. Anal. Calcd for
C35H28N2O2: C, 82.65; H, 5.55; N, 5.51. Found: C, 81.74;
H, 5.63; N, 5.39.
(
s, 1H, Ar3CH), 3.77 (s, 6H, OMe). 13C NMR (125 MHz,
CDCl3) δ 157.47, 149.35, 148.23, 147.98, 147.65, 142.84,
1
36.39, 134.42, 133.76, 133.02, 129.54, 129.23, 128.59,
28.18, 126.22, 123.78, 123.41, 111.27, 55.87, 43.71. FT-IR
1
(
KBr) νmax 3027, 2931, 2836, 1607, 1503, 1474, 1288,
1
249, 1113, 1065, 1022, 801, 751, 712 cm−1. Anal. Calcd
for C31H26N2O2: C, 81.20; H, 5.72; N, 6.11. Found: C,
1.15; H, 5.70; N, 6.06.
,3'-((p-tolylmethylene)bis(4-methoxy-3,1-phenylene))
General procedure for SMC reaction of aryl bromides
with phenyl boronic acid using Pd(OAc) / L1–4 catalytic
2
8
system under ambient conditions (Table 2)
3
dipyridine (L2) White solid. Yield 68%. Mp 184–187 °C.
A 25-ml round-bottom ꢃask equipped with a stir bar was
charged with Pd(OAc)2 (0.5 mol%), L1–4 (0.5 mol%) and
4 mL of DMF. After stirring for 5 min, the aryl bromide
1a–i (1 mmol) and phenyl boronic acid 4b (1.5 mmol) and
K3CO3 (2 mmol) were added. The resulting mixture was
stirred at room temperature for appropriate time. The reac-
tion mixture was ꢂltered through a Celite, and solvents were
removed under reduced pressure. The crude product was
puriꢂed by performing a ꢃash chromatography on silica gel
(eluent: n-Hexane/EtOAc10:2) obtaining the pure products
6a–k.
1
8
7
7
H NMR (500 MHz, CDCl3) δ 8.66 (d, J = 2.4 Hz, 2H),
.47 (dd, J1=4.9 Hz, J2=1.7 Hz, 2H), 7.66–7.70 (m, 2H),
.45 (dd, J1=8.4 Hz, J2=2.5 Hz, 2H), 7.23–7.26 (m, 2H),
.50 (d, J =2.5 Hz, 2H), 7.08 (d, J = 8.2 Hz, 2H), 6.98 (d,
J = 8.4 Hz, 2H), 6.23 (s, 1H, Ar3CH), 3.77 (s, 6H, OMe),
2
1
1
1
4
1
.33 (s, 3H, Me). 13C NMR (125 MHz, CDCl3) δ 157.56,
47.99, 147.59, 139.65, 136.46, 135.55, 133.70, 133.41,
32.11, 132.03, 131.85, 131.83, 129.58, 129.10, 128.90,
28.56, 128.48, 128.39, 126.10, 123.34, 111.37, 55.87,
3.35, 21.01. FT-IR (KBr) νmax 3672, 3460, 2986, 2901,
452, 1407, 1220, 1066, 893, 772 cm−1. Anal. Calcd for
1-([1,1'-biphenyl]-4-yl)ethanone (6a) White solid. Mp
116–118 °C (lit. [128] 119–122 °C). 1H NMR (500 MHz,
CDCl3) δ 8.04 (d, J=8.0 Hz, 2H), 7.69 (d, J=8.2 Hz, 2H),
7.63 (d, J=9.0 Hz, 2H), 7.44–7.52 (m, 2 H), 7.35–7.44 (m,
1 H), 2.63 (s, 3H). 13C NMR (125 MHz, CDCl3) δ 197.57,
145.74, 139.87, 135.92, 128.93, 128.87, 128.20, 127.23,
127.18, 26.56. FT-IR (KBr) νmax 3097, 2922, 1679, 1426,
1402, 1359, 1219, 1119, 836 cm−1.
C32H28N2O2: C, 81.33; H, 5.97; N, 5.93. Found: C, 81.20;
H, 5.69; N, 5.87.
3
,3'-(((3-nitrophenyl)methylene)bis(4-methoxy-
3
7
8
1
,1-phenylene))dipyridine (L3) White solid. Yield
6%. Mp 186–188 °C. 1H NMR (500 MHz, CDCl3) δ
.66 (s, 1H), 8.50 (d, J = 3.6 Hz, 1H), 8.08 (d, J = 7.9 Hz,
H), 7.97 (s, 1H), 7.68 (d, J = 7.7 Hz, 2H), 7.36–7.51
(
(
m, 7H), 7.27–7.30 (m, 1H), 6.90–7.10 (m, 5H), 6.78
d, J = 8.7 Hz, 1H), 6.23 (s, 1H, Ar3CH), 3.76 (s, 3H,
General procedure for SMC reaction of aryl chlorides
OMe), 3.70 (s, 3H, OMe). 13C NMR (125 MHz, CDCl3)
δ 157.25, 156.27, 148.44, 147.97, 147.91, 145.19, 136.08,
with phenyl boronic acid using Pd(OAc) / L1–3 catalytic
2
system under thermal conditions (Table 3)
1
1
1
3
1
35.00, 133.76, 132.84, 132.47, 131.03, 130.91, 130.08,
28.94, 128.47, 127.05, 123.96, 123.41, 121.48, 112.95,
12.70, 111.57, 55.81, 55.73, 43.74. FT-IR (KBr) νmax
008, 2935, 2838, 1719, 1607, 1529, 1504, 1440, 1397,
350, 1287, 1249, 1219, 1186 cm−1. Anal. Calcd for
An oven-dried two-necked ꢃask equipped with a condenser
and a stir bar was charged with Pd(OAc)2 (2 mol%), L1–3
(2 mol%) and DMF (4 mL). Two cycles of vacuum-argon
were applied and the resulting mixture was stirred for 5 min.
Then, aryl bromide 8a–f (1 mmol), phenyl boronic acid 4b
(1.5 mmol) and K2CO3 (2 mmol) were added. The reaction
mixture was stirred at 100 °C for allotted times. After cool-
ing to room temperature, the reaction mixture was ꢂltered
through a Celite, and solvents were removed under reduced
pressure. The crude product was puriꢂed according to the
described method in Sect. 4.2.3 to obtain the pure products
6n–u.
C31H25N3O4: C, 73.94; H, 5.00; N, 8.34. Found: C,
7
3.81; H, 4.96; N, 7.25.
3
,3'-((naphthalen-1-ylmethylene)bis(4-methoxy-
3
,1-phenylene))dipyridine (L4) Yellow oil. Yield 42%.
1
H NMR (500 MHz, CDCl3) δ 8.57 (s, 1H), 8.43 (d,
J = 3.8 Hz, 1H), 7.99 (d, J = 8.3 Hz, 1H), 7.84 (m, 1H),
7
.73 (d, J = 8.1 Hz, 1H), 7.69–7.65 (m, 2H), 7.60–7.58
m, 1H), 7.56–7.53 (m, 1H), 7.48–7.44 (m, 3H),
.43–7.39 (m, 2H), 7.33 (dd, J1 = 7.6 Hz, 1H), 7.20 (dd,
J1 = 7.8 Hz, J2 = 4.8 Hz, 1H), 7.04–7.03 (m, 1H), 7.01
(
7
4-methyl-2-nitro-1,1'-biphenyl (6k) Yellow oil. 1H
NMR (500 MHz, CDCl3) δ 7.65–7.70 (bs, 1H), 7.37–7.45
(m, 4H), 7.30–7.35 (m, 3H), 2.48 (s, 3H). 13C NMR
(125 MHz, CDCl3) δ 149.18, 138.65, 137.45, 133.49,
132.92, 131.71, 128.57, 127.97, 127.94, 124.32, 20.79.
(
s, 1H, Ar3CH), 6.99–6.98 (m, 1H), 3.78 (s, 3H, OMe).
1
1
1
3C NMR (125 MHz, CDCl3) δ 157.41, 147.73, 147.40,
39.42, 136.46, 134.04, 133.83, 132.72, 132.00, 129.53,
28.74, 128.62, 127.22, 126.36, 126.00, 125.88, 125.32,
1
3

Journal of the Iranian Chemical Society
FT-IR (KBr) νmax 3060, 3029, 2924, 2856, 1602, 1528,
482, 1444, 1356, 1272, 1148, 1075, 1038 cm−1.
2,4-dichloro-6-phenylpyrimidine (6x) White Solid. Mp
1
1
98–101 °C. H NMR (500 MHz, CDCl ) δ 8.02–8.10 (m,
3
1
3
2
H), 7.46 (s, 1H), 7.42–7.60 (m, 3H). C NMR (125 MHz,
General procedure for SMC reaction of aryl bromides
CDCl ) δ 168.14, 162.89, 160.95, 134.07, 132.42, 129.19,
3
with aryl boronic acid using Pd(OAc) / L1–4 catalytic
127.56, 115.26 ppm. FT-IR (KBr) ν
3063, 2924, 1599,
max
2
−
1
system under US irradiation (Table 2)
1554, 1518, 1325, 1249, 1145, 818, 774, 688 cm .
Supplementary Information The online version contains supplemen-
To a mixture of Pd(OAc)2 (0.5 mol%), L1–4 (0.5 mol%),
aryl bromide 1a–k (1 mmol), and aryl boronic acids 4b–d
tary material available at https://doi.org/10.1007/s13738-021-02373-y.
(
1.5 mmol) and K2CO3 (2 mmol) was added 4 mL of DMF.
Acknowledgements We are grateful to the research council of the
The resulting mixture was sonicated for appropriate time at
Vali-e-Asr University of Rafsanjan for ꢂnancial support of this work.
3
0% amplitude using the P-US irradiation mode (Pulsed-
mode US, the probe is on for 10 Sec / The probe is oꢀ for 10
Sec). The reaction mixture was puriꢂed as described in the
References
4
.2.3 section to obtain the pure products 6a–m. The prod-
uct 6 l was also synthesized using double SMC reaction of
substrate 1j with twofold amounts of phenyl boronic acid 4b
under similar conditions.
1. R.K. Friedman, K.M. Oberg, D.M. Dalton, T. Rovis, Pure Appl.
Chem. 82, 1353 (2010)
2
3
. M. Rueping, B. J. Nachtsheim, Beilstein J. Org. Chem. 6 (2010)
https://doi.org/10.3762/bjoc.6.6
2
-chloro-1,1'-biphenyl (6m) Yellow oil (lit. [129]
. A. Buchcic, S. Zawisza, M. Leśniak, Rachwalski. Catalysts 10,
971 (2020)
3
1
1
1
1
4 °C). 1H NMR (500 MHz, CDCl3) δ 7.28–7.66 (m, 9H).
3C NMR (126 MHz, CDCl3) δ 140.59, 139.45, 132.55,
31.37, 129.94, 129.44, 128.74, 128.50, 128.03, 127.58,
27.16, 126.79. FT-IR (KBr) νmax 3023, 2934, 1586, 1568,
466, 1421, 1035, 722, 698 cm−1.
4
5
. G.D. Yadav, D.P. Wagh, ChemistrySelect 5, 9059 (2020)
. S. Das, B. Porashar, S. Saikia, R. Borah, ChemistrySelect 5, 3041
(
2020)
6
7
. Yanga, S. Gao, Chem. Soc. Rev. 47 (2018) 7926 and references
cited therein.
. M. M. Heravi, M. Ghanbarian, V. Zadsirjan, B. Alimadadi Jani,
Monatshefte für Chemie (2019) DOI: https://doi.org/10.1007/
s00706-019-02465-9 and references cited therein.
General procedure for SMC reaction of aryl chlorides
with aryl boronic acids using Pd(OAc) / L1–3 catalytic
2
8. K. Sanshiro, Synthesis of Organometallic Compounds: A Prac-
tical Guide; Chichester: John Wiley & Sons, (1997) ISBN:
system under US irradiation (Table 3)
9
78–0–471–97195–5
9
. A. Fürstner, G. Leitner, Seidel. Org. Synth. 81, 33 (2004)
A mixture of Pd(OAc) (2 mol%), L1–3 (2 mol%), aryl chlo-
2
1
1
0. M. Trost, M.L. Crawley, Chem. Rev. 103, 2921 (2003)
1. J.-P. Corbet, G. Mignani, Chem. Rev. 106, 2651 (2006)
ride 8a–h (1 mmol), aryl boronic acids 4b–d (1.5 mmol),
K CO (2 mmol), and 4 mL of DMF was sonicated for allot-
12. V.V. Namboodiri, R.S. Varma, Green Chem. 3, 146 (2001)
2
3
1
1
3. N. Miyaura, A. Suzuki, Chem. Rev. 95, 2457 (1995)
4. V.F. Slagt, A.H.M. de Vries, J.G. de Vries, R.M. Kellogg, Org.
Process Res. Dev. 14, 30 (2010)
ted time at 100% amplitude using the continuous-ultrasonic
irradiation mode (C-US mode). The reaction mixture was
puriꢂed as described in the 4.2.3 section to obtain the pure
products 6n–y.
1
1
1
5. K. Tamao, K. Sumitani, M. Kumada, J. Am. Chem. Soc. 94, 4374
(1972)
6. R. J. P. Corriu, J. P. Massé, J. Chem. Soc., Chem. Commun.
(1972) 144.
3
-nitro-2-phenylpyridine (6v) Yellow oil (lit. [130]
1
Yellow oil). H NMR (500 MHz, CDCl ) δ 8.85 (dd,
1
3
7. Y. Hatanaka, T. Hiyama, J. Org. Chem. 53, 918 (1988)
J = 4.75 Hz, J = 1.6 Hz, 1H), 8.13 (dd, J = 8.15 Hz,
2
1
18. E.-I. Negishi, Angew. Chem. Int. Ed. 50, 6738 (2011)
19. J.M. Hass, R. Hammann, P. Greiner, Knochel. ACS Catal. 6,
1540 (2016)
J = 1.6 Hz, 1H), 7.52–7.60 (m, 2H), 7.35–7.50 (m, 4H).
2
1
3
C NMR (125 MHz, CDCl ) δ 152.83, 152.33, 152.08,
3
2
0. C. Cordovilla, J.M. Bartolomé, P. Martínez-llarduya, Espinet.
1
1
1
36.33, 134.10, 132.09, 129.73, 128.69, 128.08, 122.90,
ACS Catal. 5, 3040 (2015)
22.34. FT-IR (KBr) ν
3046, 2924, 1591, 1560, 1438,
max
21. C.G. Blettner, W.A. König, W. Stenzel, T. Schotten, J. Org.
−
1
355, 1219, 817, 772 cm .
Chem. 64, 3885 (1999)
2
2. V. K. Olkhovik, D. A. Vasilevskii, A. A. Pap, G. V. Kalechyts, Y.
V. Matveienko, A. G. Baran, N. A. Halinouski, V. G. Petushok,
Arkivoc ix (2008) 69 and references cited therein.
3. M. Tobisu, T. Xu, T. Shimasaki, N. Chatani, J. Am. Chem. Soc.
133, 19505 (2011)
4
,6-dichloro-2-phenylpyrimidine (6w) White Solid. Mp
1
9
2
6–100 °C. H NMR (500 MHz, CDCl ) δ 8.12–8.16 (m,
3
1
3
H), 8.01 (s, 1H), 7.45–7.60 (m, 3H). C NMR (125 MHz,
2
2
CDCl ) δ 167.63, 135.67, 131.62, 129.06, 127.59, 127.44,
3
4. C. Wolf, H. Xu, J. Org. Chem. 73, 162 (2008)
1
1
10.90. FT-IR (KBr) ν
3060, 2925, 1572, 1513, 1497,
max
−
1
25. J. Han, Y. Liu, R. Guo, J. Am. Chem. Soc. 131, 2060 (2009)
237, 1072, 820, 744, 688 cm .
2
6. F.-S. Han, Chem. Soc. Rev. 42, 5270 (2013)
1
3

Journal of the Iranian Chemical Society
2
7. S. Xu, E.H. Kim, A. Wei, E.-I. Negishi, Sci. Technol. Adv. Mater.
61. M. Gholinejad, Z. Naghshbandi, C. Nájera, ChemCatChem 11,
1792 (2019)
1
5, 044201 (2014). https://doi.org/10.1088/1468-6996/15/4/
0
44201
62. N. Hussain, A. Borah, G. Darabdhara, P. Gogoi, V.K. Azhagan,
M.V. Shelke, M.R. Das, New J. Chem. 39, 6631 (2015)
63. M. Opanasenko, P. Štěpnička, J. Čejka, RSC Adv. 4, 65137
(2014)
2
2
3
8. X.-Y. Lu, L.-Y. Yan, J.-S. Li, J.-M. Li, H.-P. Zhou, R.-C. Jiang,
C.-C. Liu, R. Lua, R. Hu, Chem. Commun. 56, 109 (2020)
9. P.K. Prajapati, S. Saini, S.L. Jain, J. Mater. Chem. A 8, 5246
(
2020)
64. M. Zarei, M.A. Zolꢂgol, A.R. Moosavi-Zare, E. Noroozizadeh,
Org. Chem. Res. 4, 43 (2018)
0. S.K. Gurung, S. Thapa, A. Kaꢃe, D.A. Dickie, R. Giri, Org. Lett.
1
6, 1264 (2014)
65. V. Polshettiwar, C. Len, A. Fihri, Coord. Chem. Rev. 253, 2599
(2009)
3
3
1. Chatterjee, T. R. Ward, Catal Lett 146 (2016) 820
2. K.C. Nicolaou, P.G. Bulger, D. Sarlah, Angew. Chem. Int. Ed.
66. Erigoni and U. Diaz, Catalysts 11 (2021) 79, DOI: https://doi.
org/10.3390/catal11010079
4
4, 4442 (2005)
3
3. S. Gallagher-Duval, G. Hervé, G. Sartori, G. Enderlin, C. Len,
New J. Chem. 37, 1989 (2013)
67. M. Nasrollahzadeh, Molecules 23, 2532 (2018). https://doi.org/
10.3390/molecules23102532
3
3
4. R. Martin, S.L. Buchwald, Acc. Chem. Res. 41, 1461 (2008)
5. S.E. Hooshmand, B. Heidari, R. Sedghi, R.S. Varma, Green
Chem. 21, 381 (2019)
68. M.A. Zolꢂgol, V. Khakyzadeh, A.R. Moosavi-Zare, A. Rostami,
A. Zare, N. Iranpoor, M.H. Beyzavi, R. Luque, Green Chem. 15,
2132 (2013)
3
6. Z. Li, C. Gelbaum, Z.S. Campbell, P.C. Gould, J.S. Fisk, B.
Holden, A. Jaganathan, G.T. Whiteker, P. Pollet, C.L. Liotta,
New J. Chem. 41, 15420 (2017)
69. M.A. Zolꢂgol, T. Azadbakht, V. Khakyzadeh, R. Nejatyamid,
D.M. Perrin, RSC Adv. 4, 40036 (2014)
70. M. Aghayee, M.A. Zolꢂgol, H. Keypour, M. Yarie, L. Moham-
madi, Appl. Organometal. Chem. 30, 612 (2016)
71. D. Wang, W. Liu, F. Bian, W. Yu, New J. Chem. 39, 2052 (2015)
72. T. Azadbakht, M.A. Zolꢂgol, R. Azadbakht, V. Khakyzadeh,
D.M. Perrin, New J. Chem. 39, 439 (2015)
3
7. Taheri Kal Koshvandi, M. M. Heravi, T. Momeni, Appl Organo-
metal Chem. 32 (2018) e4210, DOI:https://doi.org/10.1002/aoc.
4
210.
3
3
4
8. L.-C. Campeau, K. Fagnou, Chem. Commun. (2006) 1253
9. F. Littke, G.C. Fu, Angew. Chem. Int. Ed. 41, 4176 (2002)
0. J.B. Shaik, V. Ramkumar, B. Varghese, S. Sankararaman, Beil-
stein J. Org. Chem. 9, 698 (2013)
73. V. Kandathil, B.D. Fahlman, B.S. Sasidhar, S.A. Patil, S.A. Patil,
New J. Chem. 41, 9531 (2017)
74. R. Andrés, E. de Jesús, J.C. Flores, New J. Chem. 31, 1161
(2007)
4
1. S. Handa, E.D. Slack, B.H. Lipshutz, Angew. Chem. Int. Ed. 54,
1
994 (2015)
75. C.P. Perumgani, S.P. Parvathaneni, B. Kodicherla, S. Keesara,
M.R. Mandapati, Inorg. Chim. Acta 455, 105 (2017)
76. M. Nasrollahzadeh, M. Sajjadi, M. Shokouhimehr, R.S. Varma,
Coord. Chem. Rev. 397, 54 (2019)
4
4
2. S. Muthumari, R. Ramesh, RSC Adv. 6, 52101 (2016)
3. S.V. Bhosale, M.B. Kalyankar, S.V. Bhosale, S.J. Langford, E.F.
Reid, C.F. Hogan, New J. Chem. 33, 2409 (2009)
4
4
4
4
4
4
5
5
4. M.-Q. Yan, J. Yuan, F. Lan, S.-H. Zeng, M.-Y. Gao, S.-H. Liu, J.
Chen, G.-A. Yu, Org. Biomol. Chem. 15, 3924 (2017)
5. J.-J. Ning, J.-F. Wang, Z.-G. Ren, D.J. Young, J.-P. Lang, Tetra-
hedron 71, 4000 (2015)
77. Wolfson and O. Levy-Ontman, Catalysts 10 (2020) 136, DOI:
https://doi.org/10.3390/catal10010136.
78. M.R. Buchmeiser, T. Schareina, R. Kempe, K. Wurst, J. Orga-
nomet. Chem. 634, 39 (2001)
6. A.-E. Wang, J.-H. Xie, L.-X. Wang, Q.-L. Zhou, Tetrahedron 61,
79. B. Tao, D.W. Boykin, Tetrahedron Lett. 43, 4955 (2002)
80. Y.-Z. Zhu, Z.-P. Li, J.-A. Ma, F.-Y. Tang, L. Kang, Q.-L. Zhou,
A. S. C. Chan, Tetrahedron: Asymmetry 13 (2002)161
81. M.S. Grasa, J. Viciu, C. Huang, M.L. Zhang, S.P. Trudell, Nolan.
Organometallics 21, 2866 (2002)
2
59 (2005)
7. S. Mohanty, D. Suresh, M.S. Balakrishna, J.T. Mague, J. Orga-
nomet. Chem. 649, 2114 (2009)
8. G. Liu, F. Han, C. Liu, H. Wu, Y. Zeng, R. Zhu, X. Yu, S. Rao,
G. Huang, J. Wang, Organometallics 38, 1459 (2019)
9. V. Polshettiwar, A. Decottignies, C. Len, A. Fihri, Chemsuschem
82. Mazet, L. H. Gade, Eur. J. Inorg. Chem. (2003) 1161
83. S. Shotwell, H. L. Ricks, J. G. M. Morton, M. Laskoski, J. Fiscus,
M. D. Smith, K. D. Shimizu, H.-C. zur Loye, U. H. F. Bunz, J.
Organomet. Chem. 671 (2003) 43
3
, 502 (2010)
0. O. Maluenda, Navaro. Molecules 20, 7528 (2015). (and refer-
ences cited therein)
84. K. Verma, R.R. Jha, R. Chaudhary, R.K. Tiwari, A.K. Danodia,
Adv. Synth. Catal. 421, 421 (2013)
1. L. Kantam Mannepalli, C. Gadipelly, G. Deshmukh, P. Likhar,
S. Pottabathula, Bull. Chem. Soc. Jpn. 93 (2020) 355
2. Sindhuja, R. Ramesh, Y. Liu, Dalton Trans. 41 (2012) 5351
3. K. Rao, A. Kumar, B. Kumar, D. Kumar, A.K. Singh, Dalton
Trans. 41, 1931 (2012)
85. Y. Zhang, X. Luan, Y. Han, X. Wang, C. Wen, J. Ding, J. Gao,
Green Chem. 15, 2081 (2013)
5
5
86. Y. Zhang, L. Zhang, X. Zhang, D. Yang, C. Du, L. Wan, C. Au,
J. Chen, M. Xie, New J. Chem. 44, 15202 (2020)
87. L.-Y. Xu, C.-Y. Liu, S.-Y. Liu, Z.-G. Ren, D.J. Young, J.-P. Lang,
Tetrahedron 73, 3125 (2017)
5
4. P. Mao, L. Yang, Y. Xiao, J. Yuan, X. Liu, M. Song, J. Orga-
nomet. Chem. 705, 39 (2012)
5
5
5. N. Shahnaz, B. Banik, P. Das, Tetrahedron Lett. 54, 2886 (2013)
6. X. Tang, Y.-T. Huang, H. Liu, R.-Z. Liu, D.-S. Shen, N. Liu, F.-S.
Liu, J. Organomet. Chem. 729, 95 (2013)
88. Q. Li, L.-M. Zhang, J.-J. Bao, H.-X. Li, J.-B. Xie, J.-P. Lang,
Appl. Organometal. Chem. 28, 861 (2014)
89. P.K. Byers, A.J. Canty, R.T. Honeyman, J. Organomet. Chem.
385, 417 (1990)
5
5
7. M. N. Zafar, M. F. Nazar, S. H. Sumrra, G. E-Saba, A. Yasmin,
A. H. Atif, Russ. J. Coord. Chem. 42 (2016) 225
90. R. Mohammadiannejad, R. Hosseini, C.R. Ranjbar-Karimi,
Chimie 23, 363 (2020)
8. B. Lamia, A. Chakchouk-Mtibaa, B. Hallouma, L. Mansour, L.
Mellouli, I. Özdemir, S. Yaşar, N. Hamdi, Molecules 22, 420
91. R.A. Shenvi, D.P. Ómalley, P.S. Baran, Acc. Chem. Res. 42, 530
(2009)
(
2017). https://doi.org/10.3390/molecules22030420
5
6
9. O. Oloyede, H. Görls, J.A.O. Woods, W. Plass, A.O. Eseola, J.
Mol. Struct. 1197, 336 (2019)
92. M.D. Graaf, K.D. Moeller, J. Org. Chem. 81, 1527 (2016)
93. F. R. Pinacho Crissótomo, R. Carillo, T. Martín, F. García-
Tellado, V. S. Martín, J. Org. Chem. 70 (2005) 10099
94. B.M. Trost, Science 219, 245 (1983)
0. L.-M. Zhang, H.-Y. Li, H.-X. Li, D.J. Young, Y. Wang, J.-P.
Lang, Inorg. Chem. 56, 11230 (2017)
1
3

Journal of the Iranian Chemical Society
9
5. T. Verlee, T. van der Heugebaert, P.I. Meer, F.V. Kerchev, C.V.
Breusegem, Stevens. Beilstein J. Org. Chem. 13, 303 (2017)
6. G. Nagendrappa, Reson. 13, 929 (2008)
114. X. Gao, P. Lu, Y. Ma, Polymer 55, 3083 (2014)
115. R. Rajagopal, D. V. Jarikote, K. V. Srinivasan, Chem. Commun.
(2002) 616.
9
9
7. X. Zhang, T.-L. Wang, C.-D. Huo, X.-C. Wang, Z.-J. Quan,
Chem. Commun. 54, 3114 (2018)
116. M.R. Panahi, J.M. Naimi-Jamal, J. Organomet. Chem. 868, 36
(2018)
9
8. Z. Dehbanipour, M. Moghadam, S. Tangestaninejad, V.
Mirkhani, I. Mohammadpoor-Baltork, Appl. Organometal.
Chem. 32, e4436 (2018). https://doi.org/10.1002/aoc.4436
9. A. Kashani, M. Landarani-Isfahani, S. Moghadam, V. Tangesta-
ninejad, I. Mirkhani, Mohammadpoor-Baltork. Appl. Organo-
metal. Chem. 32, e4440 (2018). https://doi.org/10.1002/aoc.4440
117. Mohammadpoor-Baltork, M. Moghadam, S. Tangestaninejad, V.
Mirkhani, K. MohammadiannejadAbbasabadi, H. R. Khavasi,
Eur. J. Org. Chem. (2011) 1357.
9
118. K. Mohammadiannejad-Abbasabadi, I. MohammadpoorBaltork,
S. Tangestaninejad, M. Moghadam, V. Mirkhani, R. Kia, Tetra-
hedron 72, 1433 (2016)
1
1
1
1
1
1
1
00. M. A. Zolꢂgol, F. Shirini, A. Ghorbani Choghamarani, Synthesis
119. K. Mohammadiannejad, R. Ranjbar-Karimi, F. Haghighat, New
J. Chem. 43, 5543 (2019)
(
2006) 2043
01. M. Safaiee, M. Moeinimehr, M.A. Zolꢂgol, Polyhedron 170, 138
120. K. Mohammadiannejad, R. Ranjbar-Karimi, F. Haghighat, Poly.
Arom. Comp. (2019). https://doi.org/10.1080/10406638.2019.
1604555.22
(
2019)
02. G. Hasaninejad, M.A. Chehardoli, Zolꢂgol and A. Abdoli, Phos-
phorus, Sulfur and Silicon 186, 271 (2011)
121. M. Mohammadpoor-Baltork, S. Moghadam, V. Tangestaninejad,
K. Mirkhani, M.A. MohammadiannejadAbbasabadi, Zolꢂgol, ,
J. Iran. Chem. Soc. 8, 840 (2011)
03. G. Chehardoli, M.A. Zolꢂgol, Phosphorus. Sulfur and Silicon
1
85, 193 (2010)
04. Ghorbani-choghamarani, M. A. Zolꢂgol and T. Rastegar, Chin.
J. Catal. 30 (2009) 273
122. R. Ranjbar-Karimi, Ultrason. Sonochem. 17, 768 (2010)
123. R. Ranjbar-Karimi, M. Mashak-Shoshtari, A. Darehkordi, Ultra-
son. Sonochem. 18, 258 (2011)
05. Amani, M. A. Zolꢂgol, A. Ghorbani-Choghamarani and M. Haj-
jami, Monatsh. Chem. 140 (2009) 65
124. J. Rodríguez-Aguilar, B. Ordóñez, M. Vidal, M.C. Rezende, M.
Domínguez, SynOpen 1, 24 (2017)
06. M.A. Zolꢂgol, K. Amani, A. Ghorbani-Choghamarani, M. Haj-
jami, R. Ayazi-Nasrabadi, S. Jafari, Catal. Commun. 9, 1739
125. H. Aghahosseini, M. R. Saadati, S. J. Tabatabaei Rezaei, A.
Ramazani, N. Asadi, H. Yahiro3, M. Mori, N. Shajari, A. R.
Kazemizadeh, Sci. Rep. 11 (2021) 10239.
(
2008)
1
07. Kawada, A. Arimura, T. Tsuri, M. Fuji, T. Komurasaki, S.
Yonezawa, A. Kugimiya, N. Haga, S. Mitsumori, M. Inagaki,
T. Nakatani, Y. Tamura, S. Takechi, T. Taishi, J. Kishino, M.
Ohtani, Angew. Chem. Int. Ed. 137 (998) 973.
126. Zolꢂgol, Tetrahedron 57 (2001) 9509.
127. M. Mohammadpoor-Baltork, S. Moghadam, V. Tangestaninejad,
K. Mirkhani, M.A. MohammadiannejadAbbasabadi, C.R. Zolf-
igol, Chimie 14, 934 (2011)
1
1
1
08. F. Littke, G.C. Fu, Angew. Chem. Int. Ed. 37, 3387 (1998)
09. F. Schoenebeck, K.N. Houk, J. Am. Chem. Soc. 132, 2496 (2010)
10. M. Vieira, B.T. Dalberto, F.L. Coelho, P.H. Schneider, Ultrasonic
Sonochemistry 68, 105228 (2020). https://doi.org/10.1016/j.ultso
nch.2020.105228
128. J. Hill, M.D. Bowman, B. Esselman, S.D. Byron, J. Kreitinger,
N.E. Leadbeater, J. Chem. Educ. 91, 1054 (2014)
129. J.M.A. Miguez, L.A. Adrio, A. Sousa-Pedrares, J.M. Vila, K.K.
Hii, J. Org. Chem. 72, 7771 (2007)
1
1
11. R.B. Said, Salem, Advances in Chemical. Eng. Sci. 6, 111 (2016)
12. J.A. Azua, P. Mata, E. Heymes, F. Peris, J. Lamaty, E. Martinez,
Colacino. Adv. Synth. Catal. 355, 1107 (2013)
130. M. Ali, A. McKillop, M.B. Mitchell, R.A. Rebelo, P.J. Wallbank,
Tetrahedron 48, 8117 (1992)
1
13. D. Garella, S. Tagliapietra, V.P. Mehta, E. Van der Eycken, G.
Cravotto, Synthesis 1, 136 (2010)
Authors and Aꢀliations
Raziyeh Hosseini · Reza Ranjbar‑Karimi1 · Kazem Mohammadiannejad2
1
2
Kazem Mohammadiannejad
kmmohammadi@gmail.com
NMR Laboratory, Faculty of Science, Vali-E-Asr University
of Rafsanjan, Rafsanjan 77176, Islamic Republic of Iran
1
Department of Chemistry, Vali-E-Asr University
of Rafsanjan, Rafsanjan 77176, Islamic Republic of Iran
1
3