N-Hetercocyclic carbene metallacrown ethers based on 1, 8-dihydroxy- 9, 10-anthraquinone: Synthesis, structures and application in situ palladium-catalyzed SuzukieMiyaura reaction

Article abstract of DOI:10.1016/j.jorganchem.2013.07.001

N-Hetercocyclic carbene precursors containing 1,8-dihydroxy-9,10- anthraquinone derivative: 1,8-bis(3-(N-R-imidazole)propoxy)-9,10-anthraquinone 2X (L1H₂: R = PhCH₂, X = Br, L3H₂: R = _nBu, X = PF₆, L4H₂: R = PhCH₂, X = PF₆, L5H₂: R = PyCH₂, X = PF₆), 1,8-bis(2-(N-R-imidazole)ethoxy)-9,10-anthraquinone 2X (L2H₂: R = PhCH₂, X = PF₆) and 1,8-bis(3-(N-R-imidazole)propoxy) anthracene 2X (L6H₂: R = PhCH₂, X = PF₆) were synthesized. N-Heterocyclic carbene metallacrown ethers: L1AgBr (1), L2AgPF ₆ (2), L3AgPF₆ (3), L4AgPF₆ (4), L6AgPF ₆ (5), L4AuPF₆ (6), L5Hg(PF₆)2 (7) have been prepared. Complexes 1-7 were characterized by elemental analysis, NMR spectroscopy and single crystal X-ray diffraction. Particularly, complex 4 and PdCl₂(CH₃CN)₂ synergetically and efficiently catalyzed in situ SuzukieMiyaura cross-coupling reaction in 100% aqua-phase.

Full text of DOI:10.1016/j.jorganchem.2013.07.001

Journal of Organometallic Chemistry 743 (2013) 147e155
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Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
N-Hetercocyclic carbene metallacrown ethers based on 1,8-dihydroxy-
9,10-anthraquinone: Synthesis, structures and application in situ
palladium-catalyzed SuzukieMiyaura reaction
Wei Tang, Wei-Guan Yuan, Bo Zhao, Hong-Ling Zhang, Fang Xiong, Lin-Hai Jing,
*
Da-Bin Qin
Key Laboratory of Chemical Synthesis and Pollution Control of Sichuan Province, School of Chemistry and Chemical Engineering,
China West Normal University, Nanchong 637002, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
N-Hetercocyclic carbene precursors containing 1,8-dihydroxy-9,10-anthraquinone derivative: 1,8-bis(3-
(N-R-imidazole)propoxy)-9,10-anthraquinone 2X (L1H2: R ¼ PhCH2, X ¼ Br, L3H2: R ¼ nBu, X ¼ PF6,
L4H2: R ¼ PhCH2, X ¼ PF6, L5H2: R ¼ PyCH2, X ¼ PF6), 1,8-bis(2-(N-R-imidazole)ethoxy)-9,10-
anthraquinone 2X (L2H2: R ¼ PhCH2, X ¼ PF6) and 1,8-bis(3-(N-R-imidazole)propoxy)anthracene 2X
(L6H2: R ¼ PhCH2, X ¼ PF6) were synthesized. N-Heterocyclic carbene metallacrown ethers: L1AgBr (1),
L2AgPF6 (2), L3AgPF6 (3), L4AgPF6 (4), L6AgPF6 (5), L4AuPF6 (6), L5Hg(PF6)2 (7) have been prepared.
Complexes 1e7 were characterized by elemental analysis, NMR spectroscopy and single crystal X-ray
diffraction. Particularly, complex 4 and PdCl2(CH3CN)2 synergetically and efficiently catalyzed in situ
SuzukieMiyaura cross-coupling reaction in 100% aqua-phase.
Received 8 May 2013
Received in revised form
26 June 2013
Accepted 1 July 2013
Keywords:
N-Heterocyclic carbene
1,8-Dihydroxy-9,10-anthraquinone
derivative
In situ aqua-phase catalysis
SuzukieMiyaura reaction
Ó 2013 Elsevier B.V. All rights reserved.
1. Introduction
oxoether-bridged bis-(imidazolium) ligand [21]. Chen et al. re-
ported bidentate NHC-bridged polynuclear silver metallacrown
Since first stable imidazol-2-ylidene was isolated by Arduengo
in 1991 [1], N-heterocyclic carbenes (NHCs) have been proved to be
efficient ancillary ligands and alternative ligands of typical phos-
phines [2]. The properties of N-heterocyclic carbenes resemble
ethers [22]. N-Heterocyclic carbene complexes exhibiting fluores-
cent may be good candidates for fluorescent switch [23e25].
Anthracene and anthraquinone derivative as fluorescence group
were applied to molecular recognition [26]. To the best of our
knowledge, few N-Heterocyclic carbene metallacrown ethers
involving 1,8-dihydroxy-9,10-anthraquinone derivative have been
reported.
Our group is interested in the metallacrown ether and catalytic
performance of N-heterocyclic carbene metal complexes. In this
paper, we reported the synthesis, structural characterization of
seven new silver(I), gold(I) and mercury(II) NHC metallacrown
ethers complexes involving 1,8-dihydroxy-9,10-anthraquinone
derivative. Moreover, catalytic performance of silver NHC com-
plex 4 and PdCl2(CH3CN)2 in SuzukieMiyaura reactions in pure
water was studied.
those of electron-donating phosphines as robust
s-donors with
negligible -accepting ability [3]. NHCs have become widespread
p
ligands in coordination chemistry [4e7]. Metal-NHC complexes
have been found ubiquitous applications in homogeneous and
asymmetric catalysis [8e12], pharmaceutical science [13e15] and
photoelectric material [16,17]. Organic crown ethers have been
used as multifunctional ligands in many aspects because of their
remarkable size selectivity for some small molecules and metal
ions [18]. Therefore, the metal ions centered into crown to form
metallacrown ether. Metallacrown ether is a kind of chemical
structure which is significantly different from that of either the
metal center or the crown ether [19,20]. So far, there are some
reports concerning N-heterocyclic carbene metallacrown ethers
have been described in the published work. Cavell et al. prepared
2. Results and discussion
2.1. Synthesis and structures of silver-NHC complexes 1e5
1,8-Dihydroxy-9,10-anthraquinone underwent alkylation
with 1,2-dibromoethane or 1,3-dibromopropane to provide
* Corresponding author. Fax: þ86 817 256 8081.
E-mail address: qdbkyl@cwnu.edu.cn (D.-B. Qin).
0022-328X/$ e see front matter Ó 2013 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.jorganchem.2013.07.001

148
W. Tang et al. / Journal of Organometallic Chemistry 743 (2013) 147e155
1,8-bis(2-bromoethoxy)-9,10-anthraquinone (a) or 1,8-bis(3-
bromopropoxy)-9,10-anthraquinone (b) [27,28]. Compound
c
was obtained by reduction of the 1,8-dihydroxy-9,10-
anthraquinone at first and underwent alkylation with 1,3-
dibromopropane [29]. The NHCs bis-(imidazolium) salts L1H2
were prepared from imidazole by stepwise alkylation with
benzyl bromide in the presence of NaH in THF at 70 ꢀC for 48 h,
followed by quarterization with 1,8-bis(3-bromopropoxy)-9,10-
anthraquinone in sequence (method 1, Scheme 1). Precursors of
L2H2eL5H2 were obtained by two steps. The first step is in a
manner similar to that for L1H2, and the second step is through
an anionic exchange with ammonium hexafluorophosphate in
methanol (method 2, Scheme 1). Precursors of L2H2eL5H2 are
stable towards air and moisture, soluble in organic solvents
such as acetonitrile and dimethyl sulfoxide, and insoluble in
diethyl ether and petroleum ether.
Synthetic methods of complexes 1e5 were shown in Scheme
2. Treatment of the bis-(imidazolium) salts L1H2eL4H2 and
L6H2 with Ag2O in DMSO for 2 days in the dark under nitrogen
atmosphere obtained silver-NHC complexes 1e5. The structures
of complexes 1e5 were confirmed by elemental analysis, 1H
NMR, 13C NMR spectroscopy and X-ray crystallography. In the 1H
NMR spectra of L1H2eL4H2 and L6H2, the imidazolium protons
Scheme 2. Synthesis of silver NHC complexes 1e5.
angle of C(10)eAgeC(33) is 171.65(13)ꢀ. The AgeC(10) and Age
ꢀ
C(33) bond lengths are 2.075(4) and 2.078(3) A, respectively.
Complex 4 is mononuclear and crystallized as triclinic, Pꢁ1 space
group (Fig. 4), compared with the complex 1, which has a different
anion (Fig. 4), the angle of C(8)eAg(1)eC(33) is 174.69(12)ꢀ which
is little larger than the value of complex 1. The bond lengths of
signal (NCHN) appear at
d
¼ 9.10e9.40 ppm, which are consis-
tent with the chemical shifts of reported imidazolium salts [30e
32]. In the 1H NMR spectra of 1e5, the disappearance of the
resonances for the imidazolium protons (NCHN) show the for-
mation of the expected metal carbene complexes, and the
chemical shifts of other hydrogens are similar to their corre-
sponding precursors.
ꢀ
C(8)eAg(1) and C(33)eAg(1) are 2.075(4) and 2.083(4) A. In the
complexes 1 and 4 of dihedral angles which are formed by two
imidazole rings are 39.90(3) and 45.64(3)ꢀ, respectively. Moreover,
the dihedral angles which are formed by two benzene rings are
9.10(1) and 41.03(6)ꢀ, probably due to the different anion of com-
plexes 1 and 4.
Complexes 1e5 suitable for single crystal X-ray diffraction were
obtained by slow diffusion of diethyl ether into CH3OH/CH3CN so-
lution at room temperature. In NHC metal complexes 1e5 (Figs. 1e
5), each complex contains a macrometallocycle (16-membered ring
for 2, 18-membered ring for 1, 3e5) constructed by one silver atom
and bidentate chelate biscarbene ligand containing two flexible
ether chains and one rigid anthraquinone or one anthracene ring.
The coordination environment of silver atoms in these complexes
markedly depends on carbene carbons. As shown in Fig. 1, complex
1 is mononuclear and crystallized as triclinic, Pꢁ1 space group. The
crystallographic parameters are listed in Table 1. The coordination
geometry around the silver atom is nearly linear of complex 1. The
In complex 2, two benzyl groups point to the opposite di-
rections. However, two alkyl chains of complexes 3 and 5 point to
the same direction (butyl chains for 3 and benzyl groups for 5). The
molecular structure of complex 2 is shown in Fig. 2 and crystallo-
graphic data are listed in Table 1. The complex 2 which the silver
atom is coordinated with two carbene carbon atoms a linear
arrangement [C(10)eAg(1)eC(33) ¼ 173.47(14)ꢀ] is mononuclear
and crystallized as triclinic, Pꢁ1 space group. The C(10)eAg(1) and
ꢀ
C(31)eAg(1) distances are 2.105(3) and 2.092(4) A of the metal NHC
complex 2. The two imidazole rings have a dihedral angle of
Fig. 1. The molecular structure of 1. The thermal ellipsoids are drawn at the 50%
probability level. All hydrogen atoms of NHC were omitted for clarity. Selected bond
ꢀ
ꢀ
ꢀ
distances (A) and angles ( ): AgeC(10) 2.075(4), AgeC(33) 2.078(3) A; C(10)eAgeC(33)
Scheme 1. Synthesis of bis(imidazolium) precursors L1H2eL6H2.
171.65(13)ꢀ.

W. Tang et al. / Journal of Organometallic Chemistry 743 (2013) 147e155
149
Fig. 4. The molecular structure of 4. The thermal ellipsoids are drawn at the 50%
ꢁ
probability level. All hydrogen atoms of NHC and PF6 anion were omitted for clarity.
Selected bond distances (A) and angles (ꢀ): Ag(1)eC(8) 2.075(4), Ag(1)eC(33)
ꢀ
ꢀ
ꢀ
2.083(4) A; C(31)eAg(1)eC(10) 174.69(4) .
Fig. 2. The molecular structure of 2. The thermal ellipsoids are drawn at the 50%
ꢁ
probability level. All hydrogen atoms of NHC and PF6 anion were omitted for clarity.
temperature (Scheme 3). The 1H NMR spectrum of complex 6 in
DMSO-d6 is similar to complex 4. As shown in Fig. 6, the gold-NHC
complex 6 is mononuclear and crystallized as triclinic, Pꢁ1 space
group. The crystallographic parameters are listed in Table 2. The
central gold atom is biscoordinated by two carbene carbons in a
linear fashion [bond angle C(14)eAu(1)eC(33) ¼ 176.43(19)ꢀ]. The
C(14)eAu(1) and C(33)eAu(1) bond lengths are 2.043(3) and
Selected bond distances (A) and angleꢀs (ꢀ): Ag(1)eC(31) 2.092(4), Ag(1)eC(10)
ꢀ
ꢀ
2.105(3) A; C(31)eAg(1)eC(10) 173.47(14) .
39.95(9)ꢀ. Complex 3 crystallized in the monoclinic space group P2/
c, and complex 5 crystallized in the triclinic space group Pꢁ1. The
C(16)eAg(1)eC(16A) bond angle in complex 3 is 176.5(2)ꢀ, and the
C(16)eAg(1) and C(16A)eAg(1) bond lengths are the same
ꢀ
1.995(3) A, respectively. The average AueC (carbene) bond length is
in the expected range reported for other related two-coordinate
gold carbene complex [35]. The dihedral angle of the two imid-
azole rings is 46.21(2)ꢀ.
ꢀ
(2.092(5) A) (Fig. 3). The imidazole rings of complex 3 form the
dihedral angle which is 37.69(5)ꢀ. There is some difference from the
complex 5 when is compared with the complex 3 (Figs. 3 and 5).
The crystal data are found in Table 1. Coordination geometry on the
silver of complex 5 is also linear conformation, with a C(10)e
Ag(1)eC(31) angle of 174.7(3)ꢀ. This value is little larger than
171.65(13)ꢀ in 1 and 173.47(14)ꢀ in 2. The bond distances of Ag(1)e
2.3. Synthesis and structures of mercury-NHC complexes 7
Mercury (II) complex 7 was prepared by reaction of the imida-
zolium salts L5H2 with excess mercury (II) acetate in acetonitrile at
90 ꢀC for 2 days under nitrogen atmosphere (Scheme 3). After
recrystallization with acetonitrile, complex 7 was obtained as yel-
low solid. Single crystal X-ray diffraction was obtained by slow
diffusion of diethyl ether into CH3CN solution at room temperature.
The 1H NMR spectrum of complex 7 in DMSO-d6 shows the obvious
disappearance of acidic 2H-imidazolium protons, which is diag-
nostic for the loss of the carbonium protons and the formation for
metal carbene complex, and the 13C NMR spectrum of the carbene
carbon for complex 7 is at 174.4 ppm within the range reported in
ꢀ
C(10) ¼ 2.083(10) and Ag(1)eC(31) ¼ 2.088(11) A are slightly
different from 2 due to the variation of coordination environment.
The dihedral angle of two imidazole rings is 41.21(2)ꢀ. When
complex has a longer ether chain linkage, the coordination geom-
etry at the silver atom tends to be linear probably due to the flex-
ibility of the long oxoether bridge.
2.2. Synthesis and structures of gold-NHC complexes 6
Transmetalation reaction has proved to be a promising proce-
dure to obtain NHCemetal complexes [33,34]. The gold-NHC
complex 6 was formed by a transmetalation reaction between
the literature for other mercuryecarbene carbon signals (d 170e
185 ppm) [36,37].
[Au(Me2S)Cl] and the Ag-containing carbene
4
at room
Fig. 3. The molecular structure of 3. The thermal ellipsoids are drawn at the 50%
Fig. 5. The molecular structure of 5. The thermal ellipsoids are drawn at the 50%
ꢁ
ꢁ
probability level. All hydrogen atoms of NHC and PF6 anion were omitted for clarity.
probability level. All hydrogen atoms of NHC and PF6 anion were omitted for clarity.
Selected bond distances (A) and anglꢀes (ꢀ): Ag(1)eC(16) 2.092(5), Ag(1)eC(16A)
Selected bond distances (A) and angles (ꢀ): Ag(1)eC(10) 2.083(10), Ag(1)eC(31)
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
2.092(5) A; C(31)eAg(1)eC(10) 176.5(2) .
2.088(11) A; C(10)eAg(1)eC(31) 174.7(3) .

150
W. Tang et al. / Journal of Organometallic Chemistry 743 (2013) 147e155
Table 1
Crystal data and refinement parameters for complexes 1e5.
Compound
1
2
3
4
5
Formula
C40H36AgBrN4O4
824.51
Triclinic
0.33 ꢂ 0.20 ꢂ 0.08
Pꢁ1
C38H32AgF6N4O4P
861.52
Triclinic
0.20 ꢂ 0.14 ꢂ 0.10
Pꢁ1
C38H50AgF6N4O5P
895.66
Monoclinic
0.29 ꢂ 0.24 ꢂ 0.18
P2/c
9.126(6)
18.424(12)
12.506(9)
90.00
100.807(12)
90.00
C44H46AgF6N4O5P
963.69
Triclinic
0.23 ꢂ 0.21 ꢂ 0.18
Pꢁ1
C44H48AgF6N4O3P
933.70
Triclinic
0.20 ꢂ 0.18 ꢂ 0.10
Pꢁ1
Formula weight
Crystal system
Crystal size (mm)
Space group
ꢀ
a (A)
9.0056(2)
12.0808(2)
17.6199(3)
71.827(1)
88.126(1)
74.954(1)
1756.46(6)
2
11.4224(19)
11.762(2)
15.083(2)
106.247(3)
101.587(3)
105.817(3)
1785.6(5)
2
9.459(7)
13.162(9)
19.000(13)
106.616(11)
93.489(11)
103.822(11)
2180(3)
9.365(9)
13.149(12)
18.451(15)
75.012(11)
88.16(2)
75.63(3)
2125(3)
2
ꢀ
b (A)
ꢀ
c (A)
a
b
g
(ꢀ)
(ꢀ)
(ꢀ)
3
ꢀ
V (A )
2065(2)
2
Z
2
Dc (g/cm3)
Abs. coeff.
F(000)
1.559
1.602
1.440
1.468
1.459
1.759 mmꢁ1
836
0.688 mmꢁ1
872
0.599 mmꢁ1
924
0.574 mmꢁ1
988
0.583 mmꢁ1
960
qmin
,
qmax, deg
3.04, 27.48
14,501
6520
452
1.004
2.21, 26.34
8878
6153
523
1.077
2.76, 24.07
11,026
4067
252
1.037
2.29, 27.07
11,829
8374
538
1.045
1.66, 25.02
14,687
7316
534
1.095
No. of data collected
No. of unique data
No. of refined params.
Goodness-of-fit on F2
R indices (all)
a
R1
0.0436
0.1238
0.0705
0.1275
0.0778
0.1488
0.0589
0.1266
0.1311
0.3192
b
wR2
Final R indices [I > 2sigma(I)]
a
R1
0.0394
0.1202
0.0524
0.1145
0.0514
0.1330
0.0463
0.1170
0.1176
0.3085
b
wR2
P
P
a
R1 ¼ j Fo ꢁ j:Fcj:j=j jFojj.
b
wR2 ¼ [Sw(F2o ꢁ Fc2)2/Sw(F2o)2]1/2
.
Since the first report, the majority of the mercury-NHC com-
2.4. Catalytic activity of the NHC silver complex 4 with
plexes are mononuclear containing linear Hg(NHC)2 units [38e41],
although in some cases association with the counter ions distorts
the mercury environment toward tetrahedral geometry [36].
Complex 7 exhibits special conformations (Fig. 7), the mercury
atom is coordinated with two carbene carbons and two picolyl
nitrogen atoms adopting tetrahedral geometry. The Hg(1)eC(20)
PdCl2(CH3CN)2 in situ aqua-phase
The SuzukieMiyaura cross-coupling reaction of aryl halides
and arylboronic acids is of general interest in organic synthesis
and meanwhile one of the most important methods for CeC
coupling in organic synthesis [44]. The SuzukieMiyaura reaction
catalyzed by PdeNHC complexes has provided an efficient and
powerful method for the formation of carbonecarbon and car-
boneheteroatom bonds [45e49]. We chose the cross-coupling
reaction of bromobenzene with 4-methylphenylboronic acid as a
model reaction to test the solvent, base and catalyst activity
(Table 3). No product was observed when used H2O as solvent,
K3PO4$3H2O as base and silver NHC complex 4 as catalyst was
used, while added 1 mol% tetrabutyl ammonium bromide (TBAB)
as phase transfer catalyst at 50 ꢀC in 24 h in air (entry 1). Coupling
ꢀ
and Hg(1)eC(32) bond distances are 2.068(5) and 2.066(5) A,
which are a little shorter when compared to those of known
mercury-NHC complexes [42,43]. The distances of Hg(1)eN(6) and
ꢀ
Hg(1)eN(3) are 2.651(5) and 2.699(5) A, respectively. The C(20)e
Hg(1)eC(32) is nearly linear with the bond angle of 175.15(19)ꢀ. The
bond angle of N(3)eHg(1)eN(6) is 82.46(18)ꢀ. In the structure of 7,
one NHC ligand and one pyridine ring are linked by central mercury
atom forming a six-membered metallacycle which adopts a dis-
torted boat conformation. The dihedral angle between the coordi-
nated pyridine rings is 35.88ꢀ and the two imidazole rings on either
side of the mercury atom are not coplanar with angle of 28.26(6)ꢀ.
Fig. 6. The molecular structure of 6. The thermal ellipsoids are drawn at the 50%
ꢁ
probability level. All hydrogen atoms of NHC and PF6 anion were omitted for clarity.
Selected bond distances (A) and angles (ꢀ): Au(1)eC(14) 2.043(4), Ag(1)eC(33)
ꢀ
ꢀ
ꢀ
Scheme 3. Synthesis of gold and mercury NHC complexes 6e7.
2.083(4) A; C(31)eAg(1)eC(10) 174.69(4) .

W. Tang et al. / Journal of Organometallic Chemistry 743 (2013) 147e155
151
PdCl2(CH3CN)2, with K3PO4$3H2O as base at 50 ꢀC in pure water.
The results are summarized in Table 4. Aryl bromides containing
electron-donating groups (eOCH3, eNH2, eCH3, entries 1e3)
were obtained yield above 99%. Aryl bromides containing
electron-withdrawing groups (eCHO, eCOCH3, eNO2) gave high
yield over 90%, except the slightly decreased yield with nitro
substitution, probably due to the steric hindrance effect (entries
4e7). Then the cross-coupling reaction of 3-bromopyridine with
4-methylphenylboronic acid was tested to obtain the good yield
95% (entry 8). The catalysts were highly efficient toward the
coupling of iodobenzene with 4-methylphenylboronic acid to give
a near theory yield above 99% (entry 9). The coupling reaction of
chlorobenzene with 4-methylphenylboronic acid gave a yield of
85% (entry 10), while p-chloroacetophenone or p-chloroaniline
gave moderate yield of 82% and 88%, respectively (entries 11 and
12). Additionally, the coupling reactions of other arylboronic acids
bearing electron-withdrawing in the para-position with bromo-
benzene proceeded with good to excellent yields (entries 14e16).
The coupling of bromobenzene with phenylboronic acid gave a
good yield of 95% (entry 13). Though various catalysts have been
developed for the SuzukieMiyaura reactions [50e53], a few
catalysts can have a good yield both in aryl bromide and aryl
chloride [54e56]. The above results show that complex 4 and
PdCl2(CH3CN)2 have high catalytic activity for aryl bromide and
aryl chloride in pure water.
Table 2
Crystal data and refinement parameters for complexes 6 and 7.
Compound
6
7
Formula
C40H38AuF6N4O5P
996.66
0.23 ꢂ 0.18 ꢂ 0.14
Triclinic
Pꢁ1
C38H34F12HgN6O4P2
1129.24
0.60 ꢂ 0.44 ꢂ 0.22
Monoclinic
P2(1)/c
18.164(5)
11.863(2)
20.333(4)
90.00
109.05(2)
90.00
4141.4(16)
4
Formula weight
Crystal size (mm3)
Crystal system
Space group
ꢀ
a (A)
9.535(6)
13.125(6)
19.087(12)
106.953(10)
93.315(12)
105.027(7)
2184(2)
2
ꢀ
b (A)
ꢀ
c (A)
a
b
g
(ꢀ)
(ꢀ)
(ꢀ)
3
ꢀ
V (A )
Z
Dc (g/cm3)
Abs. coeff.
F(000)
1.513
1.811
3.475 mmꢁ1
984
3.897 mmꢁ1
2216
qmin
,
qmax, deg
2.35, 19.26
12,098
8471
433
1.012
2.50, 14.68
8732
7708
619
0.885
No. of data collected
No. of unique data
No. of refined params.
Goodness-of-fit on F2
Final R indices (all)
a
R1
0.1091
0.1722
0.0789
0.0599
b
wR2
Final R indices [I > 2sigma(I)]
a
R1
0.0652
0.1477
0.0360
0.0560
b
wR2
P
P
a
R1 ¼ j Fo ꢁ j:Fcj:j=j jFojj.
b
wR2 ¼ [Sw(F2o ꢁ Fc2)2/Sw(F2o)2]1/2
.
2.5. Fluorescent emission spectra of precursors L4H2 and complexes
4 and 6
The fluorescent emission spectra of precursors L4H2 and
complexes 4 and 6 in acetonitrile (1 ꢂ 10ꢁ6 mol/L) at room tem-
perature are obtained upon excitation at 295 nm (Fig. S27). Pre-
cursor L4H2 exhibits intense emission band in the region of 360e
yield exceeded 99%, when catalyst was changed to PdCl2(CH3CN)2
and silver NHC complex 4 (entry 2). However, using acetonitrile as
solvent, coupling yield dropped to 77% (entry 3). The common
bases, such as K2CO3, Na2CO3, and NaHCO3 gave medium yield in
pure water (entries 4, 5, 7). Poor yield was obtained using KOH as
base (entry 6). In order to further study the catalytic activity of
PdCl2(CH3CN)2 and complex 4, the control experiment was per-
formed, in which PdCl2(CH3CN)2 was added in the absence of
complex 4 with the optimized conditions, and only 26% coupling
yield was observed (entry 8).
380 nm, which can be attributed to intraligand nep* and pep*
transitions. Complexes L4H2 and 6 exhibit a broad emission band
in the region of 455e475 nm. Complexes 4 and 6 show emission
band in the region of 345e355 nm, the fluorescent emission of
complexes 4 and 6 are weaker than their precursor L4H2, which
may be assigned to the incorporation of metaleligand coordina-
tion interaction [57,58].
Various aryl halides and arylboronic acids were chosen to
explore the catalytic activity of silver NHC complex 4 and
3. Conclusions
In summary, we have synthesized and characterized the
first N-hetercocyclic carbene metallacrown ether containing
1,8-dihydroxy-9,10-anthraquinone derivative of silver, gold and
mercury complexes. Each of complexes 1e6 possesses a mac-
rometallocycle, complex
2 contain a 16-membered macro-
metallocycle and complexes 1, 3e6 possess an 18-membered
macrometallocycle, which is formed by a one metal atom
and one bidentate chelate carbene ligand. Complex 7 exhibits
flexibility conformations, the mercury atom is coordinated with
two carbene carbons and two pyridine nitrogen atoms adopting
tetrahedral geometry. In the structure of 7, one NHC ligand and
one pyridine ring are linked by central mercury forming a six-
membered metallacycle which adopts a distorted boat confor-
mation. Above of the study in the catalytic activity of NHC
silver complex 4 and PdCl2(CH3CN)2 in SuzukieMiyaura cross-
coupling reactions show that they can catalyze the coupling
reaction of aryl halides (iodide, bromide, chloride) with aryl-
boronic acids in pure water as solvent and K3PO4$3H2O as base
in air. The macrocyclic structures of NHC metal complex sug-
gest that they have potential applications in the organic
chemistry.
Fig. 7. The molecular structure of 7. The thermal ellipsoids are drawn at the
ꢁ
50% probability level. All hydrogen atoms of NHC and PF6 anions were omitted
for clarity. Selected bond distances (A) and angles (ꢀ): Hg(1)eC(32) 2.066(5),
ꢀ
ꢀ
Hg(1)eC(20) 2.068(5), Hg(1)eN(6) 2.651(5), Hg(1)eN(3) 2.699(5) A; C(32)e
Hg(1)eC(20) 175.15(19), C(32)eHg(1)eN(6) 82.46(18), C(20)eHg(1)eN(6)
100.71(18), C(32)eHg(1)eN(3) 105.96(16), C(20)eHg(1)eN(3) 78.19(17), N(6)e
Hg(1)eN(3) 82.96(15)ꢀ.

152
W. Tang et al. / Journal of Organometallic Chemistry 743 (2013) 147e155
Table 3
Optimization of the SuzukieMiyaura coupling reaction in pure water.a
1%mol cat base
solvent air
B(OH)2
Br
Entry
Solvent
Base
Yieldb (%)
1c
2d
3
4
5
H2O
H2O
CH3CN
H2O
H2O
H2O
H2O
H2O
K3PO4$3H2O
Trace
>99
77
81
82
34
60
26
K3PO4$3H2O
K3PO4$3H2O
Na2CO3
K2CO3
KOH
6
7
NaHCO3
K3PO4$3H2O
8e
a
Reaction conditions: 4-bromotoluene 0.20 mmol, 4-methylphenylboronic acid 0.22 mmol, base 0.44 mmol, solvent 2 mL, 50 ꢀC, 24 h.
Isolated yield.
Reaction conditions are the same as [a], 1 mol% TBAB and 1 mol% 4 was added.
Reaction conditions are the same as [a], 1 mol% PdCl2(CH3CN)2, 1 mol% TBAB and 1 mol% 4 were added in the reaction.
Reaction conditions are the same as [a], only PdCl2(CH3CN)2 and 1 mol% TBAB were added in the absence of complex 4.
b
c
d
e
4. Experimental
hexafluorophosphate. The product was collected by filtration and
washed with methanol. Yield: 3.42 g (75%). Anal. Calcd for
4.1. General comments
C
38H34F12N4O4P2: C, 50.68; H, 3.81; N, 6.22%. Found: C, 50.59; H,
3.79; N, 6.27%. 1H NMR (400 MHz, DMSO-d6, 25 ꢀC):
d
9.37 (s, 2H),
All manipulations were performed using standard Schlenk
techniques under an atmosphere of nitrogen. And solvents were
purified by standard procedures. Other reagents used for the
synthesis were commercially available and were used without
further purification. N-Substituted imidazoles were prepared
according to reported procedures [59,60]. NMR spectra were
recorded on an advance Z 400 Brucker (1H NMR, 400 MHz; 13C
8.35e8.37 (m, 2H), 8.07 (t, J ¼ 2 Hz, 2H), 7.74e7.80 (m, 10H), 7.50e
7.53 (m, 2H), 7.41 (t, J ¼ 4 Hz, 2H), 7.26e7.28 (m, 2H), 5.53 (s, 4H),
4.72 (t, J ¼ 4.6 Hz, 4H), 4.52 (t, J ¼ 4.6 Hz, 4H) ppm. 13C NMR
(100 MHz, DMSO-d6, 25 ꢀC):
d 183.23, 182.24, 157.62 153.70, 149.78,
137.80, 135.22, 134.44, 123.94, 123.63, 123.33, 123.24, 122.77, 120.61,
119.64, 67.93, 53.52, 48.93, 31.34 ppm.
The following di-imidazolium salts L3H2eL5H2 were prepared
in analogous to that for L2H2.
NMR, 100 MHz, respectively). Chemical shifts (
d
) were expressed
in ppm downfield to TMS at
d
¼ 0 ppm and coupling constants
(J) were expressed in Hz. Elemental analysis were measured
using a PerkineElmer 2400C Elemental Analyzer. The lumines-
cent spectra were conducted on a Cary Eclipse fluorescence
spectrophotometer.
4.4. Synthesis of 1,8-bis(3-(3-(n-butyl)-imidazole-2-ylidene)
propoxy)-9,10-anthraquinone dihexafluorophosphate(L3H2)
Yield: 3.09 g (72%). Anal. Calcd for C34H42F12N4O4P2: C, 47.45;
H, 4.92; N, 6.51%. Found: C, 47.48; H, 4.87; N, 6.53%. 1H NMR
(400 MHz, DMSO-d6, 25 ꢀC):
d 9.12 (s, 2H), 7.76e7.81 (m, 8H),
4.2. Synthesis of 1,8-bis(3-(3-benzyl-imidazole-2-ylidene)
7.54e7.56 (m, 2H), 4.54 (t, J ¼ 6.6 Hz, 4H), 4.09e4.16 (m, 8H),
3.35e3.41 (m, 4H), 2.38 (t, J ¼ 6.2 Hz, 4H), 1.66e1.69 (m, 4H), 0.81
(t, J ¼ 7.5 Hz, 6H) ppm. 13C NMR (100 MHz, DMSO-d6, 25 ꢀC):
propoxy)-9,10-anthraquinone dibromide (L1H2)
To a solution of 3-(benzyl)-1H-imidazole (1.58 g, 10 mmol)
in THF (50 mL) was added 1,8-bis(3-bromopropoxy)-9,10-
anthraquinone (2.35 g, 5 mmol). The mixture was refluxed for 2
days. The orange precipitate was isolated and washed with THF
(20 mL), and dried in vacuo. Yield: 3.00 g (75%). Anal. Calcd for
d
183.59, 182.39, 158.14, 136.57, 135.06, 134.60, 123.85, 123.09,
123.03, 120.69, 119.23, 65.62, 49.05, 46.44, 31.71, 29.13, 19.18,
13.67 ppm.
C
40H38Br2N4O4: C, 60.16; H, 4.80; N, 7.02%. Found: C, 60.05; H, 4.81;
4.5. Synthesis of 1,8-bis(3-(3-benzyl-imidazole-2-ylidene)
propoxy)-9,10-anthraquinone dihexafluorophosphate (L4H2)
N, 6.98%. 1H NMR (400 MHz, DMSO-d6, 25 ꢀC):
d
9.18 (s, 2H), 7.78e
7.80 (m, 2H), 7.75e7.76 (m, 6H), 7.50e7.53 (m, 2H), 7.26e7.31 (m,
10H), 5.34 (s, 4H), 4.52 (t, J ¼ 6.6 Hz, 4H), 4.10 (t, J ¼ 5.8 Hz, 4H),
2.32e2.37 (m, 4H) ppm. 13C NMR (100 MHz, DMSO-d6, 25 ꢀC):
Yield: 3.38 g (73%). Anal. Calcd for C40H38F12N4O4P2: C, 51.73;
H, 4.12; N, 6.03%. Found: C, 51.77; H, 4.08; N, 6.12%. 1H NMR
(400 MHz, DMSO-d6, 25 ꢀC):
d 9.24 (s, 2H), 7.80e7.83 (m, 4H),
d
183.53, 182.37, 157.99, 136.64, 134.99, 134.92, 134.85, 134.51,
129.27, 129.04, 128.46, 123.71, 123.33, 123.10, 120.57, 119.17, 65.44,
52.32, 46.44, 28.91 ppm.
7.77e7.79 (m, 4H), 7.74e7.76 (m, 2H), 7.54e7.56 (m, 6H), 7.31e7.40
(m, 4H), 5.50 (s, 4H), 4.58 (t, J ¼ 6.4 Hz, 4H), 4.14 (t, J ¼ 5.8 Hz, 4H),
2.35e2.41 (m, 4H) ppm. 13C NMR (100 MHz, DMSO-d6, 25 ꢀC):
d
180.20, 154.52, 137.57, 132.83, 129.17, 129.12, 129.09, 128.32,
4.3. Synthesis of 1,8-bis(2-(3-benzyl-imidazole-2-ylidene)ethoxy)-
9,10-anthraquinone dihexafluorophosphate (L2H2)
127.78, 126.50, 124.12, 122.52, 120.54, 114.99, 103.56, 65.90, 54.31,
49.70, 31.00 ppm.
This compound was prepared via two steps. The first step is
mixture of 3-(benzyl)-1H-imidazole (1.58 g, 10 mmol) and 1,8-
4.6. Synthesis of 1,8-bis(3-(3-picolyl-imidazole-2-ylidene)
bis(2-bromoethoxy)-9,10-anthraquinone (2.23 g,
5
mmol) in
propoxy)-9,10-anthraquinone dihexafluorophosphate (L5H2)
THF (50 mL) was stirred and refluxed for 2 days. A yellow precipi-
tate was isolated and washed with THF (20 mL) and dried in vacuo.
The second step is an anionic exchange with ammonium
Yield: 2.55 g (55%). Anal. Calcd for C38H36F12N6O4P2: C, 49.04; H,
3.90; N, 9.03%. Found: C, 49.09; H, 4.05; N, 8.98%. 1H NMR

W. Tang et al. / Journal of Organometallic Chemistry 743 (2013) 147e155
153
Table 4
SuzukieMiyaura coupling reactions with various substrates.a
1%mol cat base
solvent air
R2
X
R2
B(OH)2
R1
R1
Entry
ArX
ArB(OH)2
Yieldb (%)
1
2
3
4
5
>99
>99
>99
93
Br
Br
Br
OCH3
B(OH)2
NH2
B(OH)2
B(OH)2
B(OH)2
B(OH)2
Br
Br
CHO
95
O
6
7
92
90
Br
NO2
B(OH)2
B(OH)2
O2N
Br
N
8
95
B(OH)2
Br
I
9
>99
85
B(OH)2
B(OH)2
B(OH)2
10
11
Cl
Cl
82
O
12
13
14
15
88
95
93
Cl
Br
Br
NH2
B(OH)2
B(OH)2
Cl
F
B(OH)2
89
92
Br
Br
B(OH)2
B(OH)2
16
F3C
a
Reaction conditions: aryl halide (0.2 mmol), arylboronic acids (0.22 mmol), K3PO4$3H2O (0.44 mmol), 1 mol% PdCl2(CH3CN)2, 1 mol% TBAB and 1 mol% complex 4 were
added in the reaction, water (2 mL), 50 ꢀC, 24 h.
b
Isolated yield.
(400 MHz, DMSO-d6, 25 ꢀC):
d
9.22 (s, 2H), 7.77e7.82 (m, 6H), 7.52e
4.7. Synthesis of 1,8-bis(3-(3-benzyl-imidazole-2-ylidene)propoxy)
7.55 (m, 2H), 7.28e7.33 (m, 10H), 5.36 (s, 4H), 4.53 (t, J ¼ 6.6 Hz 4H),
anthracene dihexafluorophosphate (L6H2)
4.12 (t, J ¼ 6.0 Hz, 4H), 2.33e2.39 (m, 4H) ppm. 13C NMR (100 MHz,
DMSO-d6, 25 ꢀC):
d
183.62, 182.45, 158.10, 136.76, 135.09, 135.06,
A mixture of 3-(benzyl)-1H-imidazole (1.58 g, 10 mmol) and 1,8-
bis(3-bromopropoxy)anthracene (2.26 g, 5 mmol) in THF (50 mL)
was stirred and refluxed for 2 days. A tawny precipitate was
134.61, 129.37, 128.57, 123.81, 123.44, 123.20, 120.69, 119.26, 65.56,
52.40, 46.50, 29.03 ppm.

154
W. Tang et al. / Journal of Organometallic Chemistry 743 (2013) 147e155
isolated and washed with THF (20 mL) and dried in vacuo
and through an anionic exchange with ammonium hexa-
fluorophosphate. The product was collected by filtration and
washed with methanol. Yield: 3.04 g (70%). Anal. Calcd for
4.22 (t, J ¼ 5.2 Hz, 4H), 2.35e2.41 (m, 4H) ppm. 13C NMR (100 MHz,
DMSO-d6, 25 ꢀC):
d 183.64, 181.03, 158.69, 137.72, 134.89, 134.45,
129.09, 128.20, 127.67, 123.33, 122.64, 122.47, 120.56, 118.93, 66.97,
65.30, 54.41, 49.17, 30.58 ppm.
C
40H40F12N4O2P2: C, 53.46; H, 4.49; N, 6.23%. Found: C, 53.37; H,
4.52; N, 6.18%. 1H NMR (400 MHz, DMSO-d6, 25 ꢀC):
d
9.18 (s, 2H),
4.12. Synthesis of L6Ag$PF6 (5)
7.78e7.80 (m, 2H), 7.75e7.76 (m, 6H), 7.50e7.53 (m, 2H), 7.41e7.45
(m, 2H), 7.26e7.31 (m, 10H), 5.33 (s, 4H), 4.52 (t, J ¼ 6.6, 4H), 4.10 (t,
J ¼ 5.8 Hz, 4H), 2.32e2.37 (m, 4H) ppm. 13C NMR (100 MHz, DMSO-
A
brown powder. Yield: 132 mg (77%). Anal. Calcd for
40H38AgF6N4O2P: C, 55.89; H, 4.46; N, 6.52%; found: C, 55.78; H,
4.52; N, 6.47%. 1H NMR (400 MHz, DMSO-d6, 25 ꢀC):
7.70e7.76 (m,
C
d6, 25 ꢀC):
d 158.58, 137.61, 134.80, 134.32, 128.98, 127.55, 125.84,
d
123.18, 122.52, 122.35, 120.43, 118.82, 66.83, 54.29, 52.30, 49.05,
30.45 ppm.
6H), 7.51e7.53 (m, 4H), 7.42 (d, J ¼ 1.6 Hz, 2H), 7.17e7.19 (m, 6H),
7.08e7.10 (m, 4H), 5.17 (s, 4H), 4.49 (t, J ¼ 7.0 Hz, 4H), 4.20 (t,
J ¼ 5.1 Hz, 4H), 2.31e2.37 (m, 4H) ppm. 13C NMR (100 MHz, DMSO-
d6, 25 ꢀC):
d 158.56, 137.55, 134.84, 134.40, 128.98, 128.19, 127.52,
4.8. Synthesis of L1AgBr (1)
123.15, 122.49, 122.31, 120.43, 118.84, 66.82, 54.29, 49.03,
30.42 ppm.
A mixture of Ag2O (92.8 mg, 0.4 mmol) and L1H2 (159.6 mg,
0.2 mmol) in DMSO (10 mL) were stirred at 80 ꢀC under nitrogen
atmosphere for 2 days out of light. The resulting suspension
was filtered, and water (50 mL) was added to obtain a yellow
precipitate. The precipitate was filtered, washed with diethyl ether,
4.13. Synthesis of L4AuPF6 (6)
A mixture of Ag2O (46.4 mg, 0.2 mmol) and L4H2 (185.6 mg,
0.2 mmol) in acetonitrile was stirred for 12 h at 50 ꢀC in the dark,
by that time almost all the Ag2O dissolved. [Au(Me2S)Cl]
(63.6 mg, 0.2 mmol) was added and the mixture was stirred for
4 h at room temperature. Then the solvent was removed under
vacuum. The residue was treated with diethyl ether, giving the
desired product as a yellow solid, which was filtered, washed
with diethyl ether and dried under vacuum. Yield: 127.1 mg
(65%). Anal. Calcd for C40H36F6AuN4O4P: C, 49.09, H, 3.71, N,
5.72%; found: C, 49.15; H, 3.63; N, 5.65%. 1H NMR (400 MHz,
and
CH3OH and diethyl ether. Yield: 137 mg (83%). Anal. Calcd for
40H36AgBr2N4O4: C, 58.29; H 4.40; N 6.80; found: C, 58.16; H, 4.49;
N, 6.86%. 1H NMR (400 MHz, DMSO-d6, 25 ꢀC):
7.72e7.78 (m, 4H),
a pure product was obtained by recrystallization from
C
d
7.51e7.55 (m, 4H), 7.43 (d, J ¼ 1.7 Hz 2H), 7.20 (t, J ¼ 3.3 Hz, 6H),
7.10e7.13 (m, 4H), 5.20 (s. 4H), 4.52 (t, J ¼ 7.0 Hz, 4H), 4.22 (t,
J ¼ 5.1 Hz, 4H), 2.33e2.39 (m, 4H) ppm. 13C NMR (100 MHz, DMSO-
d6, 25 ꢀC):
d 183.65, 181.03, 158.68, 137.73, 134.90, 134.44, 129.09,
128.20, 127.67, 123.29, 122.64, 122.47, 120.53, 118.92, 66.93, 54.39,
49.15, 30.55 ppm.
The following NHC silver (I) complexes were prepared in the
same procedure as that for 1.
DMSO-d6, 25 ꢀC):
d 7.71e7.78 (m, 4H), 7.48e7.58 (m, 6H), 7.20e
7.26 (m, 10H), 5.28 (s, 4H), 4.53 (t, J ¼ 7.2 Hz, 4H), 4.26 (t,
J ¼ 5.1 Hz, 4H), 2.38e2.44 (m, 4H) ppm. 13C NMR (100 MHz,
DMSO-d6, 25 ꢀC):
d 183.67, 183.65, 158.67, 137.39, 134.84, 134.45,
4.9. Synthesis of L2AgPF6 (2)
129.13, 128.39, 127.71, 123.42, 128.88, 122.63, 120.51, 118.91, 67.29,
53.83, 49.01, 30.93 ppm.
A
yellow powder. Yield: 103 mg (60%). Anal. Calcd for
C38H32AgF6N4O4P: C, 52.98; H, 3.74; N, 6.50; found: C, 52.93; H,
3.70; N, 6.47%. 1H NMR (400 MHz, DMSO-d6, 25 ꢀC):
7.71e7.78 (m,
4.14. Synthesis of L5Hg(PF6)2 (7)
d
4H), 7.53 (d, J ¼ 13 Hz, 2H), 7.46 (d, J ¼ 1.2 Hz, 2H), 7.44 (d, J ¼ 1.6 Hz,
2H), 7.33e7.35 (m, 4H), 7.07e7.09 (m, 6H), 5.43 (s, 4H), 4.59 (t,
J ¼ 4.2 Hz, 4H), 4.33 (t, J ¼ 4.2 Hz, 4H) ppm. 13C NMR (100 MHz,
Mercury acetate (64 mg, 0.40 mmol) was added to a solution of
L5H2 (154.8 mg, 0.2 mmol) in 40 mL of acetonitrile. The mixture
was refluxed for 2 days under nitrogen atmosphere, after which the
solvent was removed under reduced pressure. The yellow residue
was washed with distilled water and recrystallization from aceto-
nitrile to produce a yellow solid. Yield: 135.4 mg (60%). Anal. Calcd
for C38H34F12HgN6O4P: C, 40.42, H, 3.03, N, 7.44%. Found: C, 40.36;
DMSO-d6, 25 ꢀC):
d 183.23, 180.24, 157.62, 153.70, 149.78, 137.80,
135.22, 134.44, 123.94, 123.63, 123.24, 122.77, 120.61, 119.64, 67.93,
53.52, 48.93, 31.34 ppm.
4.10. Synthesis of L3AgPF6 (3)
H, 3.10; N, 7.37%. 1H NMR (400 MHz, DMSO-d6, 25 ꢀC):
d 8.07e8.09
(m, 2H), 7.98 (d, J ¼ 1.8 Hz, 2H), 7.86 (d, J ¼ 1.8 Hz, 2H), 7.69e7.86
(m, 6H), 7.47e7.50 (m, 2H), 7.42 (d, J ¼ 7.7 Hz, 2H), 7.20e7.24 (m,
2H), 5.56 (s, 4H), 4.75 (t, J ¼ 6.5 Hz, 4H), 4.19 (t, J ¼ 5.2 Hz, 4H),
2.53e2.56 (m, 4H) ppm. 13C NMR (100 MHz, DMSO-d6, 25 ꢀC):
A yellow powder. Yield: 106 mg (65%). Anal. Calcd for
C34H40AgF6N4O4P: C, 49.71; H, 4.91; N, 6.82%; found: C, 49.76; H,
4.87; N, 6.79%. 1H NMR (400 MHz, DMSO-d6, 25 ꢀC):
d 7.70e7.77
(m, 4H), 7.50e7.53 (m, 4H), 7.42 (d, J ¼ 1.7 Hz, 2H), 4.54 (t,
J ¼ 7.0 Hz, 4H), 4.23 (t, J ¼ 5.1 Hz, 4H), 4.03 (t, J ¼ 7.1 Hz, 4H),
2.38e2.45 (m, 4H), 1.64e1.72 (m, 4H), 1.12e1.18 (m, 4H), 0.77 (t,
J ¼ 5.1 Hz, 6H) ppm. 13C NMR (100 MHz, DMSO-d6, 25 ꢀC):
d
183.23, 182.24, 174.50, 158.49, 154.14, 149.58, 138.86, 135.30,
134.23, 125.13, 124.46, 123.92, 123.35, 122.53, 120.09, 118.91, 65.28,
54.60, 48.84, 28.19 ppm.
d
183.58, 180.98, 158.73, 134.88, 134.38, 123.21, 122.13, 122.10,
120.45, 118.87, 66.85, 51.04, 49.04, 33.50, 30.54, 19.55, 15.62,
13.81 ppm.
4.15. General procedure for the SuzukieMiyaura cross-coupling
reaction
4.11. Synthesis of L4AgPF6 (4)
In a typical reaction, aryl halide (0.2 mmol), phenylboronic acid
(0.22 mmol), base (0.44 mmol), TBAB (tetrabutyl ammonium bro-
mide 1 mol%), PdCl2(CH3CN)2 (1 mol%) and complex 4 (1 mol%) and
pure water (2 mL) were stirred at 50 ꢀC in the dark for 24 h. The
mixture was extracted by ethyl acetate (2 mL ꢂ 3). Then the solu-
tion concentrated to 1 mL. The solution was separated by column
chromatography to get the pure products.
A
yellow powder. Yield: 129 mg (73%). Anal. Calcd for
40H36AgF6N4O4P: C, 54.01; H, 4.08; N, 6.30%; found: C, 54.08; H,
4.13; N, 6.25%. 1H NMR (400 MHz, DMSO-d6, 25 ꢀC):
7.74 (t,
C
d
J ¼ 4.8 Hz, 4H), 7.53e7.55 (m, 4H), 7.44 (d, J ¼ 2 Hz, 2H), 7.20e7.21
(m, 6H), 7.13 (t, J ¼ 3.0 Hz, 4H), 5.20 (s, 4H), 4.51 (t, J ¼ 7.2 Hz, 4H),

W. Tang et al. / Journal of Organometallic Chemistry 743 (2013) 147e155
155
[16] S.U. Son, K.H. Park, Y.S. Lee, B.Y. Kim, C.H. Choi, M.S. Lah, Y.H. Jang, D.J. Jang,
Y.K. Chung, Inorg. Chem. 43 (2004) 6896e6898.
4.16. X-ray structure determinations
[17] A.B. Powell, C.W. Bielawski, A.H. Cowley, J. Am. Chem. Soc. 131 (2009) 18232e
18233.
[18] A.V. Bajaj, N.S. Poonia, Coord. Chem. Rev. 87 (1988) 55e213.
[19] J.T. Sheff, A.L. Lucius, S.B. Owens, G.M. Gray, Organometallics 30 (2011) 5695e
5709.
[20] A. Varshney, G.M. Gray, Inorg. Chem. 30 (1991) 1748e1754.
[21] D.J. Nielsen, K.J. Cavell, B.W. Skelton, A.H. White, Inorg. Chim. Acta 352 (2003)
143e150.
[22] C. Chen, H. Qiu, W.Z. Chen, Inorg. Chem. 50 (2011) 8671e8678.
[23] Q.X. Liu, F.B. Xu, Q.S. Li, H.B. Song, Z.Z. Zhang, Organometallics 23 (2004) 610e
614.
X-ray diffraction data for 1e7 were collected on a Bruker AMART
ꢀ
APEX
P
diffractometer with a Mo-K
a
(l
¼ 0.71073 A) by using
u
scan mode. The structures were solved by direct methods using
SHELXS-97 and refined by full-matrix least-squares refinement on
F2 with SHELXL-97 [60]. All atoms except hydrogen atoms were
refined with anisotropic displacement parameters. In general,
hydrogen atoms were fixed at calculated positions, and their po-
sitions were refined by a riding model. Crystallographic data were
summarized in Tables 1 and 2 for 1e7.
[24] X.M. Zhang, S.J. Gu, Q.Q. Xia, W.Z. Chen, J. Organomet. Chem. 694 (2009)
2359e2367.
[25] Q.X. Liu, A.H. Chen, X.J. Zhao, Y. Zang, X.M. Wu, X.G. Wang, J.H. Guo, Crys-
tEngComm 13 (2011) 293e305.
[26] S.K. Kim, N.J. Singh, J. Kwon, I.C. Hwang, S.J. Park, K.S. Kim, J. Yoon, Tetrahe-
dron 62 (2006) 6065e6072.
[27] Z.H. Chen, O.F. Schall, M. Alcalá, Y. Li, G.W. Gokel, L. Echegoyen, J. Am. Chem.
Soc. 114 (1992) 444e451.
[28] S. Kumar, P. Kaur, S. Kaur, Tetrahedron Lett. 43 (2002) 1097e1099.
[29] Z.W. Shi, Y. Li, G.Y. Lu, Chem. J. Chin. Univ. 26 (2005) 667e670.
[30] J.W. Wang, Q.S. Li, F.B. Xu, H.B. Song, Z.Z. Zhang, Eur. J. Org. Chem. 5 (2006)
1310e1316.
Acknowledgments
Present work was financially supported by the National Natural
Science Foundation of China (21102117), the Education Department
of Sichuan Province (09ZX010), the College Student Science and
Technology Innovation Key Foundation of China West Normal
University (42712074).
[31] Q.X. Liu, Z.Q. Yao, X.J. Zhao, A.H. Chen, X.Q. Yang, S.W. Liu, X.G. Wang,
Organometallics 30 (2011) 3732e3739.
[32] J. Dinda, S.D. Adhikary, S.K. Seth, A. Mahapatra, New J. Chem. 37 (2013) 431e
438.
Appendix A. Supplementary material
[33] D.J. Nielsen, K.J. Cavell, B.W. White, Organometallics 22 (2001) 995e1000.
[34] F.W. Li, J.J. Hu, L.L. Koh, T.S.A. Hor, Dalton. Trans. 39 (2010) 5231e5241.
[35] S. Gaillard, D. Rix, A.M.Z. Slawin, J. Lacour, S.P. Nolan, Dalton. Trans. 41 (2012)
8235e8237.
[36] A.J. Arduengo III, R.L. Harlow, W.J. Marshall, T.K. Prakasha, Heteroat. Chem. 7
(1996) 421e426.
[37] S. Pelz, F. Mohr, Organometallics 30 (2011) 383e385.
[38] H.W. Wanzlick, H.J. SchÖnherr, Angew. Chem. Int. Ed. 7 (1968) 141e142.
[39] V.J. Catalano, M.A. Malwitz, A.O. Etogo, Inorg. Chem. 43 (2004) 5714e5724.
[40] K.M. Lee, J.C.C. Chen, I.J.B. Lin, J. Organomet. Chem. 617 (2001) 364e375.
[41] Y.S. Liu, X.J. Wan, F.B. Xu, Organometallics 28 (2009) 5590e5592.
[42] K.M. Lee, J.C.C. Chen, C.J. Huang, I.J.B. Lin, CrystEngComm 9 (2007) 278e281.
[43] U.J. Scheele, S. Decher, F. Meyer, Inorg. Chim. Acta 359 (2006) 4891e4900.
[44] D.J.M. Snelders, G.V. Koten, R.J.M.K. Gebbink, J. Am. Chem. Soc. 131 (2009)
11407e11416.
[45] Z.Y. Wang, G.Q. Chen, L.X. Shao, J. Org. Chem. 77 (2012) 6608e6614.
[46] N. Stylianides, A.A. Danopoulos, D. Pugh, F. Hancock, A.Z. Gerosa, Organo-
metallics 26 (2007) 5627e5635.
[47] L. Guang, H.Q. Yang, W. Li, G.L. Zhang, Green Chem. 13 (2011) 2939e2947.
[48 Y.Q. Tang, J.M. Lu, L.X. Shao, J. Organomet. Chem. 696 (2011) 3741e3744.
[49] T. Zhang, W.F. Wang, X.X. Gu, M. Shi, Organometallics 27 (2008) 753e757.
[50] N. Marion, O. Navarro, J.G. Mei, E.D. Stevens, N.M. Scott, S.P. Nolan, J. Am.
Chem. Soc. 128 (2006) 4101e4111.
CCDC 920160, 920156, 920159, 920158, 920157, 920161 and
920162 contain the supplementary crystallographic data for 1e7
respectively. These data can be obtained free of charge from The
Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/
data_request/cif.
Appendix B. Supplementary data
Supplementary data related to this article can be found at http://
dx.doi.org/10.1016/j.jorganchem.2013.07.001.
References
[1] A.J. Arduengo, R.L. Harlow, M. Kline, J. Am. Chem. Soc. 113 (1991) 361e363.
[2] W.A. Herrmann, C. Köcher, Angew. Chem. Int. Ed. 36 (1997) 2162e2187.
[3] A. Fürstner, M. Alcarazo, H. Krause, C.W. Lehmann, J. Am. Chem. Soc. 129
(2007) 12676e12677.
[4] J. Izquierdo, G.E. Hutson, D.T. Cohen, K.A. Scheidt, Angew. Chem. Int. Ed. 51
(2012) 11686e11698.
[51] D.K. Paluru, S. Dey, A. Wadawale, V.K. Jain, J. Organomet. Chem. 728 (2013)
52e56.
[5] M. Melaimi, M. Soleilhavoup, G. Bertrand, Angew. Chem. Int. Ed. 49 (2010)
8810e8849.
[52] K.N. Sharma, H. Joshi, V.V. Singh, P. Singh, A.K. Singh, Dalton. Trans. 42 (2013)
3908e3918.
[6] L. Benhamou, E. Chardon, G. Lavigne, S. Bellemin-Laponnaz, V. César, Chem.
Rev. 111 (2011) 2705e2733.
[53] F. Alonso, I.P. Beletskaya, M. Yus, Tetrahedron 64 (2008) 3047e3101.
[54] Q.X. Liu, H. Wang, X.J. Zhao, Z.Q. Yao, Z.Q. Wang, A.H. Chen, X.G. Wang,
CrystEngComm 14 (2011) 5330e5348.
[55] C. Gao, H.J. Zhou, S.P. Wei, Y.S. Zhao, J.S. You, G. Gao, Chem. Commun. 49
(2013) 1127e1129.
[7] G.C. Vougioukalakis, R.H. Grubbs, Chem. Rev. 110 (2010) 1746e1787.
[8] M.J. Ingleson, R.A. Layfield, Chem. Commun. 48 (2012) 3579e3589.
[9] C.M. Crudden, J.M. Praetorius, J. Am. Chem. Soc. 129 (2007) 8923e8924.
[10] S. Hiroshi, K. Miaki, Y. Haruka, A. Ryuichi, S. Satoshi, J. Organomet. Chem. 726
(2013) 46e55.
[56] X.Q. Guo, Y.N. Wang, D. Wang, L.H. Cai, Z.X. Chen, X.F. Hou, Dalton. Trans. 41
(2012) 14557e14567.
[11] J.A. Akana, K.X. Bhattacharyya, P. Muller, J.P. Sadighi, J. Am. Chem. Soc. 129
(2007) 7736e7737.
[57] F.J.B. dit Dominique, H. Gornitzka, A. Sournia-Saquet, C. Hemmert, Dalton.
Trans. (2009) 340e352.
[12] K. Shun, T. Hiromu, C. Hiroyuki, O. Masaki, S. Satoshi, Adv. Synth. Catal. 354
(2012) 807e812.
[58] X.X. Zhao, J.P. Ma, D.Z. Shen, Y.B. Dong, R.Q. Huang, CrystEngComm 11 (2009)
1281e1290.
[59] F. Thomas, Y. Mehran, P.R. John, Bioorg. Med. Chem. Lett. 13 (2003) 719e722.
[60] H.M. Lee, P.L. Chiu, J.Y. Zeng, Inorg. Chim. Acta 357 (2004) 4313e4321.
[13] L. Oehninger, R. Rubbiani, I. Ott, Dalton. Trans. 42 (2012) 3269e3284.
[14] C. Edith, P.G. Luigi, D. Georges, G. Gilles, B.L. Stephane, Chem. Commun. 47
(2011) 5864e5866.
[15] W.K. Liu, R. Gust, Chem. Soc. Rev. 42 (2013) 755e773.