Preparation of palladium(II) complexes with long alkyl chain ligand incorporated in micelle

Article abstract of DOI:10.1016/j.ica.2012.05.015

Three palladium(II) complexes with a bidentate nitrogen ligand having a long alkyl chain (1, [PdCl₂(C₈-tmen)], C₈-tmen = N,N,N′-trimethyl-N′-octylethylenediamine; 2, [PdCl ₂(C₁₆-tmen)], C₁₆-tmen = N,N,N′- trimethyl-N′-cetylethylenediamine; 3, [PdCl₂(C ₈-bpy)], C₈-bpy = 4-octyl-2,2′-bipyridine) were prepared. Addition of 1 to an aqueous solution of cetyltrimethylammonium bromide gave a metallomicelle containing the Pd(II) complex (1A). The other palladium complexes (2 and 3) were not incorporated into the CTABr micelle due to the unsuitable matching between the ligand and the micelle. 1A showed good catalytic performance for Suzuki and Heck coupling reactions in water. The catalyst system for the Heck reaction in water was reusable.

Full text of DOI:10.1016/j.ica.2012.05.015

Inorganica Chimica Acta 392 (2012) 428–432
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Preparation of palladium(II) complexes with long alkyl chain ligand incorporated
in micelle
a,
⇑
a
a
a
b,
⇑
Takeyoshi Yagyu , Manabu Tonami , Kazuki Tsuchimoto , Chie Takahashi , Koichiro Jitsukawa
a
Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan
Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan
b
a r t i c l e i n f o
a b s t r a c t
Article history:
Three palladium(II) complexes with a bidentate nitrogen ligand having a long alkyl chain (1, [PdCl (C -
2
0
8
Received 9 February 2012
Received in revised form 24 April 2012
Accepted 2 May 2012
0
0
tmen)], C
8
0
-tmen = N,N,N -trimethyl-N -octylethylenediamine; 2, [PdCl
2
(C16-tmen)], C16-tmen = N,N,N -tri-
0
methyl-N -cetylethylenediamine; 3, [PdCl
2
(C
8 8
-bpy)], C -bpy = 4-octyl-2,2 -bipyridine) were prepared.
Addition of 1 to an aqueous solution of cetyltrimethylammonium bromide gave a metallomicelle contain-
ing the Pd(II) complex (1A). The other palladium complexes (2 and 3) were not incorporated into the
CTABr micelle due to the unsuitable matching between the ligand and the micelle. 1A showed good cat-
alytic performance for Suzuki and Heck coupling reactions in water. The catalyst system for the Heck
reaction in water was reusable.
Available online 1 June 2012
Keywords:
Palladium complexes
Metallomicelle
Nanoparticle
Ó 2012 Elsevier B.V. All rights reserved.
Catalytic performance
1
. Introduction
Transition metal complexes in micelle system have been uti-
strate and product through the oil–water surface is important for
smoothly keeping the catalytic cycle. The incorporation of coordi-
nation ligand for transition metal into surfactant molecules pro-
vides means of localizing many of the physicochemical
lized as catalysts for organic synthesis in water [1]. Palladium com-
plex stabilized within polymer micelles in aqueous phase or in
ionic liquid showed high catalytic activity for C–C coupling reac-
tions [2]. For green sustainable chemistry, water is an important
reaction media [3]. The composite system consisting of metal com-
plex and cationic surfactant, such as cetylpyridinium chloride, or
neutral polymer, such as polystyrene-co-poly(ethylene oxide), pro-
vides an active site for catalysis in water [4]. Since the Heck and
Suzuki reactions are known to proceed through the redox cycle be-
tween Pd(II) and Pd(0) [5], both of palladium(II) complexes formed
within micelle or polymer and palladium(0) nanoparticle stabi-
lized by surfactants are efficient catalysts for these reactions
a
properties of these ions at oil–water surface [11]. For this purpose,
new Pd(II) complexes with a long alkyl chain are designed to be
stabilized at the surface of the micelle system through hydropho-
bic interaction. Here, we describe a preparation of metallomicelle
consisting of this palladium complex and cetyltrimethylammo-
nium bromide (CTABr), and its catalytic performance for the Suzuki
and Heck reactions in water. The Pd(II) complex within CTABr mi-
celle smoothly proceeded both reactions, and moreover, it was
reusable for the Heck reaction without the phosphine ligand.
2
. Results and discussion
[
4,6,7]. In these C–C coupling reactions mediated in water, a num-
ber of stabilizing methods have been developed for the palladium
nanoparticle using anionic, cationic, or neutral surfactants and
polymer or solid supports [6,8,9]. In addition, some Pd(II) com-
plexes anchored to organic and/or inorganic supports were also
used as catalysts for the C–C coupling reactions in water [10].
In development of metallomicelle in aqueous media, metal ion
as an active center for catalysis should stay not in the core of the
micelle but at the periphery moiety, because easy transport of sub-
2
.1. Preparations of palladium complexes with an N-alkyl-
ethylenediamine ligand within micelle
For stabilizing palladium complex within micelle in aqueous
phase, three bidentate ligands with a long alkyl chain were
designed. Two ethylenediamine-type bidentate ligands, N,N,N -tri-
methyl-N -octylethylenediamine (C
N -cetylethylenediamine (C16-tmen), were prepared according to
0
0
0
8
-tmen) and N,N,N -trimethyl-
0
the methods previously reported [12]. A bipyridine-type ligand,
0
4
4
-octyl-2,2 -bipyridine (C
8
-bpy), was newly prepared through
(C
(NCCH
2
solution was dissolved easily in various
⇑
Corresponding authors. Tel./fax: +81 52 735 5211 (T. Yagyu), tel./fax 81 6 6850
261 (K. Jitsukawa).
E-mail addresses: yagyu@nitech.ac.jp (T. Yagyu), jitkk@cheng.es.osaka-u.ac.jp
-octylpyridine as a synthetic intermediate [13]. The [PdCl
tmen)] complex (1) prepared from the reaction of [PdCl
and C -tmen in CH Cl
2
8
-
) ]
3 2
6
2
(
K. Jitsukawa).
8
2
0
020-1693/$ - see front matter Ó 2012 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.ica.2012.05.015

T. Yagyu et al. / Inorganica Chimica Acta 392 (2012) 428–432
429
organic solvents such as chloroform, CH
The [PdCl (C16-tmen)] complex (2) with the longer alkyl chain
was prepared from the reaction of [PdCl (NCCH ] and C16-tmen
as well as the case of 1. The [PdCl (C -bpy)] complex (3) was also
prepared from the reaction of [PdCl (NCCH ] and C -bpy. The
structures of these complexes shown in Scheme 1 were identified
by their elemental analyses and 1H NMR spectroscopies. These
complexes were unable to dissolve in water because of low polar-
ity and the hydrophobic long alkyl chain. On the other hand, addi-
tion of surfactant, such as CTABr, to a suspension of 1 in water gave
a clear yellow solution, 1A, where the concentration of the surfac-
2
Cl
2
, acetone, and DMSO.
consisting of the palladium(II) complex (1) with moderate-size N-
alkyl ethylenediamine ligand and CTABr micelle.
2
2
3
)
2
Synthesis of metal nanoparticles requires the surfactants to in-
hibit aggregation of the ultra fine nanoparticles initially generated
[15]. New preparation method through the stabilization of the
Pd(II) complex within the micelle in aqueous phase was investi-
gated to inhibit aggregation of Pd(0) species. Reduction of Pd(II)
complex in metallomicelle 1A in water was carried out under
1 atm of hydrogen gas bubbling at 25 °C. A gray suspension of met-
2
8
2
3
)
2
8
1
allomicelle containing Pd(0) species, 1B, was obtained. The H NMR
spectrum of 1B in D
2
O showed new signals assignable to the pro-
tant was over critical micelle concentration (CMC) at 25 °C [14].
tonated C -tmen moieties, which were different from the starting
8
1
The H NMR spectra of CTABr (10 mmol/L) in D
2
O showed that
complex 1. These findings indicate the formation of Pd(0) nanopar-
ticles within the CTABr micelle. The distribution of the mean size of
1B determined by the DLS had two peaks after reduction of 1A. One
was about 130 nm and another was about 20 nm. We estimated
that the smaller size one was Pd(0) nanoparticle, which was also
characterized by TEM image.
several signals derived from the methylene and the terminal methyl
hydrogens of the cetyl group were at 0.79, 1.21, 1.29, and 1.69 ppm
and the methyl and the methylene hydrogens adjacent of the
ternary nitrogen were at about 3.09 and 3.33 ppm, respectively.
Addition of palladium complex to this solution showed the charac-
teristic behavior of metallomicelle formation. In the case of 1, the
clear D
2
O solution of 1A showed characteristic methyl and methy-
-tmen ligand
2.2. Suzuki reaction catalyzed by palladium micelle complex
lene hydrogen signals derived from the coordinated C
8
at 2.76, 2.79, and 2.86 ppm, respectively, some of which were over-
lapped with the signals derived from CTABr. The dynamic light scat-
tering (DLS) measurement revealed that the mean size of 1A,
The catalytic performance of Pd(II) species, 1A, was investigated
on the Suzuki reaction Eq. (1) in aqueous media under atmospheric
condition. Phosphine-free palladium complexes were known to
catalyze Heck and Suzuki reactions under aerobic condition [16].
Notably, phosphine-free and aqueous condition is environmentally
friendly reaction. The catalytic activities of 1A using some halo-
genobenzene derivatives are shown in Table 1. The reactions of
iodobenzene and phenylboronic acid quantitatively gave biphenyl
at 80 °C in aqueous condition under air (entries 1 and 2). Even at
60 °C, good reactivity for this reaction was shown, but very low
at 25 °C (entries 3 and 4). The reaction using bromobenzene in
the place of iodobenzene also gave biphenyl quantitatively at
80 °C (entries 5 and 6). The bromo- and/or chloro-benzenes are
acceptable for the reactant of the Suzuki reaction [17], so that
the less active chlorobenzene compared with iodo derivative also
gave the corresponding coupling product at 100 °C under the ex-
tended reaction time (entry 8). Especially, 4-chloroacetophenone
with electron-withdrawing group gave high yield of the corre-
sponding coupling product at 100 °C (entry 10). Since the rate-lim-
iting step in catalytic cycle of this cross-coupling reaction is
considered the oxidative addition step, aryl halide with electron-
withdrawing group smoothly proceeded the reaction [18]. The
reaction of bromobenzene in the presence of small amount of the
catalyst 1A also gave the coupling product quantitatively under
the extended reaction time (entry 7).
ꢁ3
consisting of 3.9 mg (1.0 ꢀ 10 mmol) of
1 and 182 mg
0.50 mmol) of CTABr in 3.0 mL of water, was 380–420 nm. Conse-
(
quently, the palladium complex 1 with alkyl chain was incorporated
into the micelle composed of CTABr to give the metallomicelle con-
taining Pd(II) complex (1A) in water. In the case of 2 or 3, however,
clear solution was not formed when addition of these complexes to
2
the CTABr micelle solution in D O. The characteristic NMR signals as
observed in 1A were not shown in 2 and 3. These finding indicate the
palladium complexes with the unfavorable ligands of the longer size
of the alkyl chain (2) or of the rigid planar structure (3) were not
incorporated into the CTABr micelle. Thus, tuning of the ligand is
important to incorporate the metal complex into the micelle. The
longer hydrophobic alkyl chain, such as cetyl, in comparison with
octyl, was not incorporated into the micelle composed with CTABr.
The more planar bipyridine unit, in comparison with alkyl ethylene-
diamine one, might be too more hydrophobic to incorporate into
CTABr micelle or be less interaction with the alkyl chains of the mi-
celle. Accordingly, the catalysis in water was investigated using 1A
Cl
Cl
Pd
Pd
1
2
:
:
Me N
NMe
2
Cl
Me N
Cl
NMe
2
Cl
N
Cl
N
Notably, the catalytic activity in the Suzuki reaction using 1B
in the place of 1A dramatically decreased. As shown in the entry
Pd
3
:
2
in Table 1, the reaction catalyzed by 1A gave biphenyl quanti-
tatively. In the same reaction condition using 1B, however, the
yield of the product decreased to 21% in 12 h reaction. Moreover,
the reaction of iodotoluene with phenylboronic acid also gave 4-
phenyltoluene at 80 °C in poor yield (18%, 8 h reaction). In this
point, Hu et al. reported that the palladium nanoparticles, of
Scheme 1. Structures of three Pd(II) complexes with bidentate ligands.

4
30
T. Yagyu et al. / Inorganica Chimica Acta 392 (2012) 428–432
Table 1
Catalytic activity of 1A for Suzuki reaction.
Entry
R
X
T (°C)
Time (h)
Yield (%)
1
2
3
4
5
6
7
8
9
H
H
H
H
H
H
H
H
I
I
I
I
Br
Br
Br
Cl
Cl
Cl
80
80
60
25
80
80
80
100
80
100
2
4
8
24
2
95
100
80
6
91
100
100
10
47
76
4
a
24
24
24
24
The Pd(II) metallomicelle, 1A, showed the catalytic activity for
both of the Heck and Suzuki reactions. The Heck reaction of sty-
COMe
COMe
1
0
3
rene, iodobenzene, and NaHCO in water was carried out in the
Reaction condition: phenylboronic acid 1.5 mmol, aryl halide 1.0 mmol, palladium
presence of 1A to give trans-stilbene (61%) accompanied with
byproduct 1,1-diphenylethylene (5%) at 100 °C for 16 h. On the
separation of the product from the reaction solution, heteroge-
neous catalyst systems have advantages in comparison with homo-
geneous ones.[8] Liquid/liquid phase separations are practical and
viable to recover, separate, and reuse the metallomicelle catalyst.
Using 1A in the aqueous solution, the recycle catalytic reaction sys-
tem was carried out under aerobic condition as shown in Scheme
ꢁ
2
content of 1A 1.0 ꢀ 10 mmol, Na
2 3 2
CO 2.0 mmol, CTABr 1.0 mmol, H O 3 mL,
under air.
a
.0 ꢀ 10ꢁ3 mmol of 1A.
1
which size were about 3 nm, generated within poly(N,N-dialkyl-
carbodiimide) became a robust catalyst for Suzuki reaction under
microwave heating.[19] Different from the case of the Heck
reaction, the catalytic activity of the Suzuki reaction might de-
pend on the size of the palladium nanoparticles.[7] The Pd(0)
nanoparticles in the metallomicelles 1B generated from the
reduction of 1A might be slightly larger size and not be suitable
for the Suzuki reaction.
2. At the first time, the Heck reaction catalyzed by 1A in the reac-
tion vessel [I] gave the coupling products under atmospheric con-
dition. To extract the organic products, heptane (a) was added to
the reaction mixture (b) [II], after the reaction. The organic phase
[III] contained stilbene (a) and the aqueous one [IV] contained 1A
(b) were separated. The oxidation state of palladium species in
[IV] was estimated as +2, since the precipitation of palladium black
2.3. Heck reaction catalyzed by palladium micelle complex
was not observed and the color of the solution was light yellow.
The reaction products were easily isolated from [III] through evap-
oration. At the next run, styrene, iodobenzene, and NaHCO were
3
added again to the remaining aqueous solution, [IV]. The isolated
yield of trans-stilbene at 100 °C for 16 h was 61% at the 1st run,
and that at the 2nd run was 54%. At the 3rd run that decreased
to 42%. The gradually decrease of yields of the products is probably
due to destruction of the micelle phase by the generated inorganic
salts. This problem is now improved for design of high perfor-
mance catalyst.
The Pd(0) nanoparticle becomes suitable catalyst for the redox
cycle reactions through the oxidative addition and reductive elim-
ination [20]. Both 1A and 1B smoothly catalyzed the Heck reaction,
because it was not influenced by the size of the palladium nano-
particle unlike the Suzuki reaction above mentioned.
The Pd(0) species in 1B within CTABr micelle was stable under
aqueous, aerobic, and even phosphine-free conditions [6]. The
coupling reaction of iodobenzene with styrene at 80 °C gave
stilbene (43%) with small amount of biphenyl (4%) as shown in
Table 2. The color change of 1B from dark gray to orange during
the reaction indicated that the oxidative addition of iodobenzene
to Pd(0) species smoothly proceeded to give aryl-Pd(II) com-
pound. The reactions of iodobenzene with tert-butylacrylate (en-
try 2) also gave the corresponding coupling products in moderate
yields (66%). The reactivity of acrylate derivatives (entries 2–4) in
this system showed the order, tert-butyl acrylate > ethyl acry-
late > methyl acrylate, which is interpreted by the hydrophobicity
of the acrylate derivatives. Using acrylic acid, the reaction with
iodobenzene did not give any coupling product (entry 5). This
finding is contrast to the previous reports, in which the reaction
of acrylic acid with iodobenzene using solid support Pd(II) com-
plex in aqueous ethanol [10] and latex-coated Pd nanocomposite
in water [21] gave cinnamic acid in good yield. Consequently, the
coupling reaction catalyzed by the palladium catalyst 1B pro-
ceeded inner phase of the micelle through the incorporation of
the substrate.
3
. Conclusion
Pd(II) complex with a bidentate nitrogen ligand having a long
alkyl chain (1, [PdCl (C -tmen)]) was incorporated into the micelle
2 8
consisting of cetyltrimethylammonium bromide (CTABr) to give a
metallomicelle (1A) in water. On the other hand, some palladium
complexes (2 and 3) with unfavorable size of the alkyl chain or ri-
gid structure were not incorporated into the CTABr micelle. Tuning
of the alkyl chain length of the ligand is important to incorporate
the complex into the micelle. The Pd(II) metallomicelle (1A)
showed good catalytic activity for Suzuki and Heck reactions in
water under atmospheric condition without phosphine ligand.
The Pd(0) nanoparticle (1B) within CTABr generated from the
reduction of 1A was not good catalyst for Suzuki reaction, although
1
B promoted Heck reaction. The catalyst system 1A was reusable
for Heck reaction in aqueous media.
Table 2
a
Catalytic activity of 1B for Heck reaction .
4. Experimental
Entry
Substrate (R)
Ph
X
Time (h)
Yield (%)
4
.1. General procedures
1
2
3
4
5
I
I
I
I
I
8
8
8
8
8
43b
66
31
10
0
CO
CO
CO
2
2
2
tBu
Et
Manipulations of the palladium complexes were carried out un-
Me
der air. Chemicals were commercially available. The substituted
ethylenediamine ligand, N,N,N’-trimethyl-N -dodecylethylenedi-
COOH
0
a
amine (C16-tmen) [12], was prepared as reported previously, and
Reaction condition: substrate 1.2 mmol, aryl halide 1.0 mmol, palladium con-
tent of 1B 1.0 mol, K CO 2.0 mmol, CTABr 0.50 mmol, H O 3 mL, 80 °C, under air.
,1-Diphenylethylene was formed as byproduct (4%).
0
0
l
2
3
2
8
N,N,N -trimethyl-N -octylethylenediamine (C -tmen) was prepared
b
1
using a similar procedure. Micelle solutions containing CTAX

T. Yagyu et al. / Inorganica Chimica Acta 392 (2012) 428–432
431
(a)
[III]
(i)
(ii)
(a)
(b)
[I]
[II]
(iii)
(b)
IV]
[
Scheme 2. Reuse System of Palladium Micelle Catalyst. [I] metallomicelle (1A) within aqueous phase. (i) Heck reaction catalyzed by palladium. [II] addition of heptane to the
reaction mixture after the reaction. (ii) separation of organic (a) and aqueous phases (b). [III] organic phase (a) containing the coupling product. [IV] aqueous phase (b)
containing catalyst. (iii) recycle use of the catalyst.
(
X = Cl, Br) was prepared using the ultrapure water. The 1H NMR
(718 mg, 0.621 mmol) indry THF(20 mL) was added 0.5 M 2-pyridyl-
zinc bromide in THF (45.0 mL, 22.5 mmol) under nitrogen. The mix-
ture was stirred for 1.5 day at rt, and an alkaline solution containing
an excess of EDTA was added. The organic layer was extracted with
spectra were recorded on Varian 300 and Bruker AV400N spec-
trometers. Elemental analyses were carried out using a Perkin
Elmer 2400 series II CHNS/O Analyzer. Dynamic light scattering
measurements were carried out using Otsuka DLS-8000. TEM mea-
surements were carried out using JEOL JEM-3010.
CH
purified by SiO
2:1) mixtures as eluent (2.44 g, 68.9%). H NMR (400 MHz, CDCl
d = 0.88 (t, 3H, CH , J = 6.9 Hz), 1.25–1.38 (m, 10H, (CH CH ), 1.69
CH ), 2.69 (t, 2H, CH (CH CH , J = 7.8 Hz), 7.14
, J = 5.0, 1.7 Hz), 7.30 (ddd, 1H, bpy-H5’, J = 7.5, 4.8,
.2 Hz), 7.81 (ddd, 1H, bpy-H4’, J = 8.0, 7.5, 1.8 Hz), 8.23 (d, 1H, bpy-
Cl
2 2
and the solvents were removed. The crude product was
2
column chromatography with hexane/acetone
1
(
3
):
4
.2. Preparation of 2-bromo-4-octylpyridine
3
)
2 5
3
(m, 2H, CH (CH )
2 2 5
3
2
)
2 6
3
Preparation was performed according to a modified method of
(
dd, 1H, bpy-H
5
the lithiation of 4-picoline [13a]. To a solution of 2-(dimethyl-
amino)ethanol (10.2 mL, 102 mmol) in dry hexane (100 mL) was
added 2.71 M n-BuLi in hexane (75.0 mL, 203 mmol) at 0 °C under
nitrogen. The mixture was stirred for 15 min at 0 °C, and a solution
of 4-octylpyridine (9.71 g, 50.8 mmol) in dry hexane (63 mL) was
added. After stirring for 1 h at 0 °C, the solution was cooled to
1
H
bpy-H
3
, J = 1.7 Hz), 8.39 (dd, 1H, bpy-H3’, J = 8.0, 1.2 Hz), 8.56 (d, 1H,
, J = 5.0 Hz), 8.69 (dd, 1H, bpy-H6’, J = 4.8, 1.8 Hz).
6
4
.4. Preparation of [PdCl
2
(C
8
-tmen)] (1)
ꢁ
78 °C. A solution of CBr
was added and stirred for 1 h at ꢁ78 °C, then the mixture was
warmed to room temperature. To the mixture was added H
4
(42.2 g, 127 mmol) in dry THF (40 mL)
A mixture of PdCl
350 mL) and 0.434 g (2.02 mmol) of C
was stirred for 5 min at room temperature. After evaporation of
the solvent, the residue was crystallized from CH Cl -hexane
0.410 g, 52.0%). Calc. for C13 Pd (391.72): C, 39.86; H,
.72; N, 7.15. Found: C, 39.63; H, 7.73; N, 6.77%. H NMR
2
(CH
3
CN)
2
(0.528 g, 2.04 mmol) in CH
2 2
Cl
(
8
-tmen in CH Cl (15 mL)
2
2
2
O
(
150 mL) at 0 °C, and the organic layer was extracted with diethyl
ether. The solution was dried with MgSO
4
and the solvents were re-
column chromatog-
raphy with hexane/EtOAc (9:1) mixtures as eluent (4.03 g, 29.3%).
2
2
(
7
2 2
H30Cl N
moved. The crude product was purified by SiO
2
1
1
(300 MHz, CDCl ): d = 0.89 (t, 3H, CH CH , J = 5.9 Hz), 1.28 (m,
H NMR (300 MHz, CDCl
.30 (m, 10H, (CH CH ), 1.61 (m, 2H, CH
CH (CH CH ), J = 8.0 Hz), 7.07 (dd, 1H, py-H
.31 (d, 1H, py-H
3
): d = 0.88 (t, 3H, CH
3
, J = 6.6 Hz), 1.26–
3
2
3
1
0H, (CH
2
)
5
CH
3
), 1.78 (m, 1H, CH
2
), 2.2–2.3 (m, 2H, CH
), 2.83 (s, 3H,
), 3.30 (m, 1H, CH ).
2
), 2.45
1
2
)
5
3
2
2
(CH )
5 3
CH ), 2.57 (t, 2H,
(
m, 1H, CH
2
), 2.58 (m, 1H, CH
2 3
), 2.82 (s, 3H, NCH
2
2
)
6
3
5
, J = 4.8, 1.2 Hz),
NCH
3
), 2.94 (s, 3H, NCH ), 3.1 (m, 2H, CH
3
2
2
7
3
, J = 1.2 Hz), 8.24 (d, 1H, py-H
6
, J = 4.8 Hz).
0
4
.3. Preparation of 4-octyl-2,2 -bipyridine
2
4.5. Preparation of [PdCl (C16-tmen)] (2)
0
Preparation of 4-octyl-2,2 -bipyridine wasperformed according to
The complex was prepared by a procedure similar to that for
[PdCl (C -tmen)], using C16-tmen as the starting material. The
product (45.9%) was obtained as orange powder. Calc. for
a modified method of the syntheses of polypyridine [13b]. To a solu-
tion of 2-bromo-4-octylpyridine (3.57 g, 13.2 mmol) and Pd(PPh
2
8
3 4
)

4
32
T. Yagyu et al. / Inorganica Chimica Acta 392 (2012) 428–432
C
21
H
46Cl
2
N
2
Pd (503.93): C, 50.05; H, 9.20; N, 5.56. Found: C, 49.53;
the iodobenzene (1.0 mmol), styrene (2.0 mmol), and NaHCO
3
1
H, 9.18; N, 5.27%. H NMR (300 MHz, CDCl
CH CH , J = 6.9 Hz), 1.26 (m, 26H, (CH ), 1.79 (m, 1H, CH
.2–2.3 (m, 2H, CH ), 2.45 (m, 1H, CH ), 2.56 (m, 1H, CH ), 2.81
s, 3H, NCH ), 2.82 (s, 3H, NCH ), 2.94 (s, 3H, NCH ), 3.13 (m, 1H,
), 3.18 (m, 1H, CH ), 3.30 (m, 1H, CH ).
3
): d = 0.88 (t, 3H,
(2.0 mmol) in sealed tube under air. The mixture was stirred at
100 °C for 20 h. The products and unreacted substrates were ex-
tracted with heptane, and the heptane solution was analyzed by
GC. To the opposite water solution remaining Pd complex and sur-
factant was added the new substrate and base.
2
3
2
)
13CH
3
2
),
2
(
CH
2
2
2
3
3
3
2
2
2
4.6. Preparation of [PdCl
2 8
(C -bpy)] (3)
References
[
1] (a) S. Bhattacharya, K. Snehalatha, S.K. George, J. Org. Chem. 63 (1998) 27;
The complex was prepared by a procedure similar to that for
PdCl (C -tmen)], using C -bpy as the starting material. The prod-
uct (60.5%) was obtained as beige powder. Calc. for C18 Pd
445.72): C, 48.51; H, 5.43; N, 6.28. Found: C, 48.44; H, 5.61; N,
(
(
b) S. Bhattacharya, K. Snehalatha, V.P. Kumar, J. Org. Chem. 68 (2003) 2741;
c) F. Hampl, F. Liska, F. Mancin, P. Tecilla, U. Tonellato, Langmuir 15 (1999)
[
2
8
8
H24Cl
2
N
2
405;
d) T. Rispens, J.B.F.N. Engberts, Org. Lett. 3 (2001) 941;
(e) J.G.J. Weijnen, J.F.J. Engbersen, Recl. Trav. Chim. Pays-Bas 112 (1993) 351;
f) J.G.J. Weijnen, A. Koudijs, G.A. Schellekens, J.F.J. Engbersen, J. Chem. Soc.,
Perkin Trans. 2 (1992) 829;
g) J.-S. You, X.-Q. Yu, X.-Y. Su, T. Wang, Q.-X. Xiang, M. Yang, R.-G. Xie, J. Mol.
Catal. A: Chem. 202 (2003) 17;
h) A.A. Hafiz, J. Surfactants Deterg. 8 (2005) 359;
(
(
1
6
1
.10%. H NMR (300 MHz, CDCl
.28–1.35 (m, 10H, (CH CH ), 1.73 (m, 2H, CH
(CH CH , J = 7.8 Hz), 7.31 (d, 1H, bpy-H
.50 (m, 1H, bpy-H5’), 7.90 (s, 1H, bpy-H ), 8.14 (m, 2H, bpy-
3’and H4’), 9.09 (d, 1H, bpy-H , J = 5.8 Hz), 9.27 (d, 1H, bpy-H6’
J = 6.0 Hz).
3
): d = 0.89 (t, 3H, CH
3
, J = 7.4 Hz),
CH ), 2.83
5
, J = 5.8 Hz),
(
)
2 5
3
2
(CH
2
)
5
3
(
(
t, 2H, CH
2
2
)
6
3
7
3
(
H
6
,
(i) A.A. Hafiz, M.Y. El Awadi, A.M. Badawi, S.M. Mokhtar, J. Surfactdnts Deterg. 8
(2005) 203;
(
j) T. Dwars, E. Paetzold, G. Oehme, Angew. Chem., Int. Ed. 44 (2005) 7174.
[
2] (a) K. Okamoto, R. Akiyama, H. Yoshida, T. Yoshida, S. Kobayashi, J. Am. Chem.
Soc. 127 (2005) 2125;
4.7. Dynamic light scattering measurement
(
b) C.C. Cassol, A.P. Umpierre, G. Machado, S.I. Wolke, J. Dupont, J. Am. Chem.
Soc. 127 (2005) 3298;
c) X. Yang, Z. Fei, D. Zhao, W.H. Ang, Y. Li, P. Dyson, J. Inorg. Chem. 47 (2008)
292;
Micelle sample solution was prepared as 182 mg (0.50 mmol) of
CTABr in 3.0 mL of water. Sample of metallomicelle including Pd(II)
(
3
complex (1A) was prepared by addition of 3.9 mg
(d) J. Zhang, W. Zhang, Y. Wang, M. Zhang, Adv. Synth. Catal. 350 (2008) 2065;
(e) M. Islam, P. Mondal, K. Tuhina, D. Hossian, A.S. Roy, Chem. Lett. 39 (2010)
ꢁ2
(
1.0 ꢀ 10 mmol) of 1 into that micelle solution, then ultrasonica-
tion. Sample of metallomicelle including Pd(0) particles (1B) was
prepared by stirring the solution of 1A under H (1 atm) at 25 °C
overnight. The averages of particle size of micelles of these solu-
tions were measured after filtration (pore size 0.1 or 0.22 m).
1200;
(
f) B.H. Lipshutz, S. Ghorai, A.R. Abela, R. Moser, T. Nishikata, C. Duplais, A.
2
Krasovskiy, J. Org. Chem. 76 (2011) 4379.
3] B.H. Lipshutz, A.R. Abela, Z.V. Boskovic, T. Nishikata, C. Duplais, A. Krasovskiy,
Top. Catal. 53 (2010) 985.
4] I.P. Beletskaya, A.N. Kashin, A.E. Litvinov, V.S. Tyurin, P.M. Valetsky, G. van
Koten, Organometallics 25 (2006) 154.
[
[
l
[
[
[
[
5] N.T.S. Phan, M.V.D. Sluys, C.W. Jones, Adv. Synth. Catal. 348 (2006) 609.
6] D. Astruc, F. Lu, J.R. Aranzaes, Angew. Chem., Int. Ed. 44 (2005) 7852.
7] I.P. Beletskaya, A.N. Kashin, I.A. Khotina, A.R. Khokhlov, Synlett (2008) 1547.
8] N.T.S. Phan, M. van der Sluys, C.W. Jones, Adv. Synth. Catal. 348 (2006) 609.
4
.8. General procedure for Suzuki coupling reaction catalyzed by 1A in
water
Aryl halide (1.0 mmol), phenylboronic acid (1.5 mmol), and
CO (2.0 mmol) were added to the metallomicelle solution
1A) composed of 363 mg (1.0 mmol) of CTABr and 3.9 mg
0.010 mmol) of 1 in 3.0 mL of water. The mixture was stirred un-
[9] (a) A. Beck, A. Horvath, A. Sarkany, L. Guczi, in Nanotechnology in Catalysis, in:
B. Zhou, S. Hermans, G. A. Somorjai (Eds.), vol. 1, Kluwer Academic, New York,
Na
(
(
2
3
2
(
004 (Chapter 5).;
b) B.J. Gallon, R.W. Kojima, R.B. Kaner, P.L. Diaconescu, Angew. Chem., Int. Ed.
46 (2007) 7251;
(
(
c) F. Durap, O. Metin, M. Aydemir, S. Ozkar, Appl. Organometal. Chem. 23
2009) 498;
2
der air. Et O and 1-butanol were added to the reaction solution,
and then the solvents were removed. The products and unreacted
J.-F. Wei, J. Jiao, J.-J. Feng, J. Lv, X-R. Zhang, X-Y. Shi, Z-G. Chen, J. Org. Chem. 74
(2009) 6283;
substrate were extracted with Et
amounts were determined by GC.
2
O from the residue and their
(
(
d) S.S. Soomro, C. Rohlich, K. Kohler, Adv. Synth. Catal. 353 (2011) 767;
e) H. Firouzabadi, N. Iranpoor, A. Ghaderi, M. Ghavami, S.J. Hoseini, Bull. Chem.
Soc. Jpn. 84 (2011) 100.
[10] (a) J. Gil-Molto, S. Karlstrom, C. Najera, Tetrahedron 61 (2005) 12168;
4.9. General procedure for Heck reaction catalyzed by 1B in water
(
1
b) A. Modak, J. Mondal, M. Sasidharan, A. Bhaumik, Green Chem. 13 (2011)
317.
Preparation of 1B was performed by the same procedure as
mentioned above. Aryl halide (1.0 mmol), olefin (1.2 mmol), and
base (K CO or NaHCO , 2.0 mmol) were added to the metallomi-
celle solution including Pd(0) particles (1B) composed of 182 mg
0.50 mmol) of CTABr and 3.9 mg (0.010 mmol) of 1 in 3.0 mL of
water under air. The mixture was stirred at 80 °C. Et O and 1-buta-
[
11] P.C. Griffiths, I.A. Fallis, D.J. Willock, A. Paul, C.L. Barrie, P.M. Griffiths, G.M.
Williams, S.M. King, R.K. Heenan, R. Gorgl, Chem. Eur. J. 4 (2004) 2022.
12] T.J. Broxton, R.A. Coa, Can. J. Chem. 71 (1993) 670.
[
[
2
3
3
13] (a) T. Kaminski, P. Gros, Y. Fort, Eur. J. Org. Chem. (2003) 3855;
(
b) Y.-Q. Fang, M.I.J. Polson, G.S. Hanan, Inorg. Chem. 42 (2003) 5.
(
[14] M. J. Rosen, Surfactant and Interfacial Phenomena, Wiley, 1978.
[15] R. G. Finke, Metal Nanoparticles. Synthesis, Characterization and Application,
Marcel Dekker, 2002.
2
nol were added to the reaction solution, then solvents were re-
moved. Products and unreacted substrate were extracted with
[
[
16] S.R. Borhade, S.B. Waghmode, Tetrahedron Lett. 49 (2008) 3423.
17] (a) A.F. Littke, C. Dai, G.C. Fu, J. Am. Chem. Soc. 122 (2000) 4020;
(b) A.F. Littke, G.C. Fu, Angew. Chem., Int. Ed. 41 (2002) 4176.
2
Et O from the residue and their amounts were determined GC
[
[
18] S.R. Chemler, D. Trauner, S.J. Danishefsky, Angew. Chem., Int. Ed. 40 (2001)
method using diethylene glycol di-n-butyl ether as standard.
4544.
19] (a) Y. Liu, C. Khemtong, J. Hu, Chem. Commun. (2004) 398;
(b) J. Hu, Y. Liu, Langmuir 21 (2005) 2121.
4.10. Reuse performance for Heck reaction of 1A
[
[
20] M.T. Reetz, E. Westermann, Angew. Chem., Int. Ed. 39 (2000) 165.
21] A. Ohtaka, Y. Kono, T. Teratani, S. Fujii, S. Matsuzawa, Y. Nakamura, R. Nomura,
Catal. Lett. 141 (2011) 1097.
To a metallomicelle solution containing 363 mg (1.0 mmol) of
CTABr and 3.9 mg (0.010 mmol) of 1 in 3.0 mL of water were added