Synthesis and structure of binuclear O/S-bridged organobismuth complexes and their cooperative catalytic effect on CO2 fixation

Article abstract of DOI:10.1002/cplu.201200030

In the synthesis of binuclear organobismuth complexes (1-6) through treatment of organobismuth chlorides with NaOH or Na2S·9H2O, the two 5,6,7,12-tetrahydrodibenz [c,f]-[1,5]azabismocine frameworks are cross-linked by either a sulfur or an oxygen atom. Th

Full text of DOI:10.1002/cplu.201200030

DOI: 10.1002/cplu.201200030
Synthesis and Structure of Binuclear O/S-Bridged
Organobismuth Complexes and Their Cooperative
Catalytic Effect on CO Fixation
2
[a]
[a]
[a]
[a]
[a]
Renhua Qiu, Zhengong Meng, Shuangfeng Yin,* Xingxing Song, Nianyuan Tan,
[
a]
[a]
[a]
[a]
[a, b]
Yongbo Zhou, Kun Yu, Xinhua Xu, Shenglian Luo, Chak-Tong Au,*
Yeung Wong*
and Wai-
[a, b, c]
In the synthesis of binuclear organobismuth complexes (1–6)
through treatment of organobismuth chlorides with NaOH
or Na S·9H O, the two 5,6,7,12-tetrahydrodibenz [c,f]-
ganobismuth complexes show higher cooperative catalytic
effect. However, the complexes with an oxygen bridge (1–3)
are not stable in air and lose their catalytic efficiency because
2
2
[1,5]azabismocine frameworks are cross-linked by either
of hydrolysis or CO adsorption (forming organobismuth carbo-
2
a sulfur or an oxygen atom. The complexes (1–6) show high
catalytic efficiency in the synthesis of cyclic carbonates from 2-
nates in the latter case). Nonetheless, the binuclear organobis-
muth complexes (4–6) with a sulfur bridge are highly stable in
air and can be applied in the synthesis of cyclic carbonates
(
chloromethyl)oxirane and CO . Compared with their precursor
2
chlorides (7–9), methoxide 10 and methanethioate 11 which
(with the co-presence of Bu NI) across various kinds of epox-
4
are mononuclear organobismuth complexes, the binuclear or-
ides, thus exhibiting satisfactory efficiency and selectivity.
Introduction
Results and Discussion
Bimetallic catalysis is commonly observed in metalloenzyme
activities Scientific activities have been devoted to construct-
In view of the recent interest in “100% atom-economical” syn-
thesis of cyclic carbonates through CO insertion into epox-
2
[
1–3]
[7]
ing bimetallic systems to mimic such actions.
fixation and transformation of CO represents a typical exam-
The chemical
ides, we primarily investigated the catalytic efficiency of the
binuclear organobismuth oxides in the interaction of CO with
2
2
[
2]
ple. To achieve cooperative action similar to that of metal-
loenzymes, the two metal atoms have to be suitably arranged
epoxides (Scheme 1). Despite the fact that binuclear organo-
bismuth oxide 1 has a framework similar to that of bimetallic
salen complexes, which exhibited high catalytic efficiency to-
[
3]
in ligand systems. Bismuth is a stable heavy element that is
free of toxicity and radioactivity. With emphasis on “green
chemistry” and “sustainable development”, it is of prime signif-
icance to investigate the potential uses of novel air-stable bi-
[2,8]
wards the reaction,
complex 1 shows no catalytic activity
when 2-methyloxirane is adopted as the substrate (Scheme 1,
Route A). Surprisingly, when 2-(chloromethyl)oxirane is adopted
as the substrate, cyclic carbonates are obtained almost quanti-
tatively (Scheme 1, Route B; Table 1, entries 1–3). Furthermore,
[
4–6]
nuclear organobismuth complexes.
However, the utilization
of this kind of bimetallic complexes in catalysis and organic
synthesis is rarely reported, especially in the cases of CO fixa-
when Bu NI was used as a co-catalyst (0.1 mol% based on ep-
2
4
[
4]
tion and transformation. For instance, there are only a few
examples of binuclear organobismuth complexes reported for
oxide), CO2 insertion into 2-methyloxirane was achieved in
a quantitative manner (Scheme 1, Route C). In contrast to those
of the monomeric organobismuth chlorides (Table 1, entries 7–
9), methoxide (Table 1, entry 10) and methane thiolate (Table 1,
[
4]
CO fixation. A typical complex is a binuclear organobismuth
2
oxide (cat. 1, Scheme 1; LBi-O-BiL, L=RN(CH C H ) , R=tBu)
2
6
4 2
that can react with CO to form a bismuth carbonate spe-
2
[
4e]
cies. To the best of our knowledge, there is no report on the
utilization of binuclear organobismuth complexes as catalysts
[
a] Dr. R. Qiu, Z. Meng, Prof. Dr. S. Yin, X. Song, Dr. N. Tan, Dr. Y. Zhou, K. Yu,
X. Xu, Prof. Dr. S. Luo, Prof. Dr. C.-T. Au, Prof. Dr. W.-Y. Wong
State Key Laboratory of Chemo/Biosensing and Chemometrics
College of Chemistry and Chemical Engineering
Hunan University, Changsha, 410082 (P. R. China)
E-mail: sf_yin@hnu.edu.cn
for the CO transformation to useful chemicals. This is partly
2
due to 1) the instability of the BiÀC/Bi bond or Bi-E-Bi (E=O, S,
[
4,5]
Br, etc.) bridge,
2) weak Lewis acidity of the poorly exposed
[
6]
bismuth centre, and 3) cooperative action of the two metal
atoms that cannot be successfully achieved owing to poor
pctau@hkbu.edu.hk
rwywong@hkbu.edu.hk
[
1–3]
[
b] Prof. Dr. C.-T. Au, Prof. Dr. W.-Y. Wong
design of the ligand system.
Department of Chemistry, Hong Kong Baptist University
Waterloo Road, Kowloon Tong, Hong Kong (P. R. China)
Herein, we report the first example of air-stable binuclear or-
ganobismuth sulfides used as the catalysts in CO transforma-
2
[
c] Prof. Dr. W.-Y. Wong
tion where the two bismuth atoms exhibiting effective cooper-
ative action.
Institute of Advanced Materials, Hong Kong Baptist University
Waterloo Road, Kowloon Tong, Hong Kong (P. R. China)
4
04
ꢀ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemPlusChem 2012, 77, 404 – 410

Homogeneous Catalysis
Table 1. Optimization of reaction condition in cyclic carbonate synthesis
from 2-(chloromethyl)oxirane and CO
2
.
o
Entry
Cat. (mol%)
t [h]
T [ C]
Yield [%]
Sel. [%]
1
2
3
4
5
6
7
8
9
1 (0.5)
2 (0.5)
3 (0.5)
4 (0.5)
5 (0.5)
6 (0.5)
7 (1.0)
8 (1.0)
9 (1.0)
10 (1.0)
11 (1.0)
–
4 (0.5)
4 (0.5)
4 (0.5)
4 (0.3)
4 (0.1)
4 (0.5)
4 (0.5)
4 (0.5)
4 (0.5)
4 (0.5)
– (0.1)
8
8
8
8
8
8
8
8
8
8
8
8
6
5
4
8
8
8
8
8
8
8
8
140
140
140
140
140
140
140
140
140
140
140
140
140
140
140
140
140
150
130
120
140
140
140
99.6
quant.
97.3
99.4
94.3
65.8
25.9
41.3
5.9
99.8
100
98.1
99.7
98.3
98.0
97.7
98.3
96.9
98.3
92.6
98.2
99.7
99.5
99.8
99.5
99.1
99.3
99.8
99.8
99.6
99.6
99.6
1
0
32.5
14.7
3.7
1
1
[
b]
12
13
14
15
16
17
18
19
20
2
Scheme 1. Selective insertion of CO into epoxides catalyzed by Cat. 1 with
or without co-catalyst Bu NI.
4
99.3
92.6
79.8
61.3
10.3
99.1
97.3
90.6
2.2
entry 11), these findings strongly suggest that binuclear orga-
nobismuth oxide shows cooperative action and is highly effi-
cient for the synthesis of cyclic carbonates from epoxides and
CO2.
[
[
[
c]
d]
e]
21
2
2
2
3
99.6
2.2
However, the binuclear organobismuth oxides 1–3 are mois-
ture and CO sensitive, and the rigorous conditions required
2
[
a] Reaction conditions: 2-(chloromethyl)oxirane (2 mL, 25 mmol), initial
CO pressure was 3.0 MPa, yield determined by GC analysis. [b] Control
experiment. [c] The substrate was 2-methyloxirane, without the co-cata-
lyst Bu NI. [d] The substrate was 2-(chloromethyl)oxirane, with the co-cat-
alyst Bu NI (0.1 mol%). [e] The substrate was 2-methyloxirane, and only
limits their utilization in catalysis. For practical application in
[6,9]
2
organic synthesis, it is better for a catalyst to be air-stable.
Interestingly, when the bridging atom is changed from an
oxygen to a sulfur atom (Scheme 2), the binuclear organobis-
muth sulfides LBi-S-BiL (4–6) are air-stable. The compounds
remain as dry crystals or powder (slightly yellow in color) for
more than one year under ambient conditions. These sulfur-
bridged binuclear organobismuth complexes represent a rare
4
4
4
Bu NI was used as the catalyst.
[
4d,5e]
class of complexes which are air-stable.
The procedure for generating complexes 4–6 is similar to
[
4e]
that of binuclear organobismuth oxide (1–3), and the com-
plexes were quantitatively prepared by the treatment of
5
,6,7,12-tetrahydrodibenz[c,f][1,5]azabismocine chloride deriva-
[
6d]
tives (7–9) with sodium sulfide. The products were charac-
1
13
terized and their structure confirmed by H and C NMR and
elemental analyses. Single crystals of 4–6 suitable for X-ray dif-
fraction were grown from a solution in toluene/n-hexane
(
CH Cl /n-hexane for 4). The ORTEP drawings of 4–6 are shown
2 2
in Figure 1 and the selected bond lengths and angles are
listed in Table 2. It is clear that the 5,6,7,12-tetrahydrodibenz-
[
c,f][1,5]azabismocine framework of complexes 4–6 is bridged
by a sulfur atom. The sulfur atom occupies a vacant site left by
the bismuth centre; the trigonal-bipyramidal coordination ge-
ometry with nitrogen and sulfur atoms in the apical positions
and carbon atoms in the equatorial positions is equatorially
distorted. The Bi1ÀN1 distance of 4–6 (2.739(4) ꢁ for 4,
Scheme 2. Synthetic routes of organobismuth complexes 1–11.
2
.710(3) ꢁ for 5, and 2.759(6) ꢁ for 6) is longer than that of the
is adopted for bridging. The results also imply that the bis-
muth centre is exposed more efficiently than that of their pre-
cursors 7–9. The Bi1ÀS1 distance of 4–6 (2.589(2) ꢁ for 4,
2.601(3) ꢁ for 5, and 2.585(6) ꢁ for 6) is longer than the Bi1–O1
corresponding precursors 7–9 (2.568(3) ꢁ for 7, 2.517(4) ꢁ for
, and 2.607(5) ꢁ for 9), thus clearly indicating the weakened
nitrogen-to-bismuth coordination in 4–6 when the sulfur atom
8
ChemPlusChem 2012, 77, 404 – 410
ꢀ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chempluschem.org
405

S. Yin, C.-T. Au, W.-Y. Wong et al.
[5f]
that of a covalent single BiÀBi bond (3.092(6)–3.2092(8)) and
[5g]
Bi=Bi bond (3.0648(2)) , thus implying that the distance be-
tween the two bismuth atoms is appropriate for maintaining
suitable stability of the bimetallic complexes. In addition, the
five atoms that are linked together, N1-Bi1-S1-Bi1A-N1A, are
almost in the same plane (distortion angle <0.58) that bisects
the butterfly-shaped tetrahydrodibenz[c,f][1,5]azabismocine
framework.
It can be seen that the four butterfly-shaped phenyl planes
of 4–6 have cis geometry and the two bismuth atoms are avail-
able for cooperative action. The nitrogen substituents of 4–6
are positioned close to the bismuth centers, thereby protect-
ing the BiÀC bond and Bi-S-Bi bridge from infringers such as
water and CO . Notably, there should be an optimum state of
2
nitrogen substituents for protection action so that the bismuth
centers are kept exposed. In comparison to those groups (Ph)
with a rigid plane and electron-withdrawing ability, the nitro-
gen substituents with flexible and electron-donating groups
(
tBu and Cy, Cy=cyclohexyl) linked to the nitrogen atom
shows positive steric and electronic effects on the bismuth
atoms, consequently enhancing the exposure and Lewis acidity
of the bismuth atoms. Furthermore, a small substituent unit
(
small tBu) is better than a big one (bulky Cy) in terms of bis-
muth exposure (see the space-filling plots of 4–6 in Figure 2).
In other words, using a sulfur atom for bridging and varying
the nitrogen substituent, one can regulate the state suitability
as well as the ligand system of the bismuth centers to mimic
those of the natural metalloenzymes.
The cooperative action of the binuclear centers was exam-
ined for the synthesis of cyclic carbonates from epoxides and
CO . First, we applied complexes 4–6 in the synthesis of cyclic
Figure 1. ORTEP plots of 4–6 with thermal ellipsoid drawn at 50% probabili-
2
ty. Hydrogen atoms are omitted for clarity.
carbonate from 2-(chloromethyl)oxirane and CO (Table 1). We
2
found that most of the complexes showed catalytic efficiency
(Table 1, entries 1–3; yield up to 99.4%, selectivity up to
Table 2. Bond lengths and angles of 4–6 in comparison with 1.
99.7%). In terms of catalytic efficiency, the nitrogen substituent
[
a]
Bond length [ꢁ]
1
4
5
6
Bi1ÀN1
2.737(6)
ꢀ4.108
2.062(6)
2.739(4)
ꢀ3.759
2.589(2)
2.710(3)
ꢀ3.639
2.601(1)
2.759(6)
3.708(6)
2.585(2)
[
b,c]
Bi1ÀBi1A
[
d]
Bi1ÀE1
Angle [8]
Bi1-E1-Bi1A
[
d]
162.9(3)
159.15(9)
ꢀ94.95
93.07(6)
157.37(9)
ꢀ105.87
88.76(4)
158.27(7)
ꢀ99.91
91.93(6)
160.5(1)
ꢀ93.04
[
d]
N1-Bi1-E1
[
c]
Ph-Ph
[a] Complex 1 is from reference [4e], E=S or O. [b] Bismuth atom dis-
tance. [c] Calculated by Mercury 1.4 (CCDC).
[
4e]
distance of 1 (2.077(6) ꢁ) and shorter than the Bi1ÀS1 dis-
tance of cationic organobismuth complexes (2.692(3)–
[
6a–c]
2.845(4 ꢁ).
The Bi1-S1-Bi1A angle of 4–6 (93.07(6)8 for 4,
88.76(4)8 for 5, and 91.93(6)8 for 6) is obviously smaller than
the Bi1-O1-Bi1A angle of 1 (162.9(3)8), thus making the two
bismuth atoms of 4–6 (Bi1ÀBi1A distance, about 3.759 ꢁ for 4,
3.639 ꢁ for 5, and 3.708(6) ꢁ for 6) closer to each other in com-
parison to the case in 1 (Bi1ÀBi1A distance of 4.108 ꢁ), and sig-
nificantly shorter than that of the sum of van der Waals radii
[
4b]
for two Bi atoms [ꢀrvdW(Bi,Bi) 4.80 ꢁ]. Nonetheless, the dis-
tance between the two bismuth atoms of 4–6 is larger than
Figure 2. Space-filling plots of complexes 4–6: (left): side view; (right): top
view.
4
06
www.chempluschem.org
ꢀ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemPlusChem 2012, 77, 404 – 410

Homogeneous Catalysis
with a flexible and electron-donating group (tBu, 4; Cy, 5) is su-
perior to that with a rigid and electron-withdrawing group (Ph,
Experimental Section
General
6
). The results indicate that through simple modification of the
nitrogen substituent in the main framework of bimetallic orga-
nobismuth complexes, one can tune the catalytic activity. It
should be noted that when an epoxide compound without
chloride, such as 2-methyloxirane, is adopted as the substrate,
the co-presence of binuclear organobismuth complex 4 and
The chemicals were purchased from Aldrich. Co., Ltd. and used as
received unless otherwise indicated. The NMR spectra were record-
ed at 258C using an INOVA-400 MHz (Varian) instrument calibrated
using tetramethylsilane (Me Si) as an internal standard. Elemental
4
analysis was performed using a VARIO EL III (Germany). The XRD re-
sults for complexes 3–5 and 11 were obtained in Hong Kong Bap-
tist University using a Smart 1000 X-ray diffractometer with CCD
co-catalyst Bu NI is required (Table 1, entries 21–23), thus de-
4
noting that the two species play a synergistic role. Sakakura
et al. pointed out that a reaction temperature of around 1508C
would be more desirable from a practical viewpoint, because
the cycloaddition reactions are highly exothermic, and effective
[11]
area detector. In all cases, the diffraction data were collected
using graphite monochromated MoKa radiation (l=0.71073 ꢁ). The
[12]
collected frames were processed with the software SAINT+ and
an absorption correction (SADABS) was applied to the collected re-
[13]
[
10]
flections. The structure was solved by direct method (SHELXTL)
in conjunction with standard difference Fourier techniques and
heat removal is fundamental for saving energy. Based on
such an understanding, we found that the optimum conditions
for the interaction are: 0.5 mol% 4, epoxide (25 mmol) with
2
[14]
subsequently refined by full-matrix least-squares analyses on F .
Hydrogen atoms were generated in their idealized positions and
all nonhydrogen atoms were refined anisotropically.
CO (initial pressure 3.0 MPa) at 1408C for 8 hours with or with-
2
out co-catalyst Bu NI (0.1 mol% based on epoxide).
4
Table 3, entries 1–6 show the performance data of 3 under
the optimized conditions across a diversity of epoxide deriva-
tives. In most of the cases, the catalyst is highly effective. As
shown in Table 3, entries 2 and 7, without the co-catalyst of
Synthesis of air-sensitive binuclear oxygen-bridged organo-
bismuth complexes of LBi-O-BiL (1–3)
The complexes [(R)N(CH C H ) Bi] O (1, R=tBu; 2, R=Cy; 3, R=Ph)
2
6
4 2
2
Bu NI, 2-methyloxirane conversion is low (2.3%). In contrast,
4
and (R)N(CH C H ) BiEMe (10, E=O; 11, E=S) were synthesized ac-
2 6 4 2
[4e,f]
when Bu NI was added, there is 99.7% CO insertion to the ep-
cording to the method developed by Yin et al.
(1.00m, 160 mL, 160 mmol) was added to a solution of azabismo-
cine chloride 7 (8.00 g, 16.1 mmol) in CH Cl (200 mL) at RT under
Aqueous NaOH
4
2
oxide. Based on the X-ray structures of 4–6, we propose that
the role of the binuclear organobismuth complexes may be
similar to that of the bimetallic Salen(Al) complex reported by
2
2
nitrogen. The reaction mixture was stirred at RT for 15 h. The or-
ganic layer was separated, washed with water (3ꢂ150 mL) and
dried over Na SO . Removal of the solvent under vacuum afforded
[
2a]
North and Pasquale Further investigations are still underway
in our laboratory.
2
4
quantitative generation of a mixture of organobismuth hydroxide
and organobismuth oxide 1 (7.60 g). Recrystallization of the mix-
ture from toluene afforded oxide 1.
2
Table 3. Synthesis of cyclic carbonates from CO and various epoxides.
1
[
{tBuN(CH C H ) Bi} O] (1): H NMR (500 MHz, CDCl , 258C, TMS):
2
6
4 2
2
3
d=8.50 (dd, J=7.3 Hz, 4H; ArH), 7.34 (dt, J=7.3 Hz, 4H; ArH), 7.26
d, J=7.0 Hz, 4H; ArH), 7.16 (dt, J=7.5 Hz, 4H; ArH), 4.27 (d, J=
5.2 Hz, 4H; CH ), 3.87 (d, J=15.2 Hz, 4H; CH ), 1.21 ppm (s, 18H;
(
1
2
2
13
1
2
tBu); C NMR (125 MHz, CDCl , 258C, TMS): d=171.50 (ArC),
3
Entry
R
R
Conv. [%]
Yield [%]
1
5
50.07(ArC), 135.54(ArC), 128.70 (ArC), 127.19 (ArC), 127.05 (ArC),
1
2
H
H
H
H
CH
H
100
99.7
100
76.2
99.5
62.1
2.3
98.2
99.7
99.8
76.0
99.5
99.3
2.3
8.04 (tBuC), 57.85 (CH ), 27.30 ppm (CH ); elemental analysis (%)
2
3
CH
CH
CH
Ph
3
2
3
calcd for C H Bi N O·C H : C 50.20, H 4.90, N 2.72; found: C 50.27,
H 4.75, N 2.77.
[
[
[
[
[
b]
c]
36 42
2
2
7
8
3
4
5
6
7
Cl
3
d]
c]
1
[{CyN(CH C H ) Bi} O] (2): H NMR (400 MHz, CDCl ,TMS): d=8.32
-CH
2
(CH
2
)
2
CH
2
-
2
6
4 2
2
3
b]
CH
3
H
(d, J=7.6 Hz, 4H; ArH), 7.34 (td, J=7.6, 1.6 Hz, 4H; ArH), 7.14–7.22
m, 8H; ArH), 3.90 (d, J=15.2 Hz, 4H; CH ), 3.77 (d, J=15.2 Hz, 4H;
(
2
[
a] Reaction conditions: 2-(chloromethyl)oxirane (2 mL), initial CO
sure was 3.0 MPa, 4 (0.5 mol%), 8 h, 1408C. [b] Without co-catalyst Bu
c] Catalyst loading of 4 was 1.0 mol%. [d] Reaction time was 12 h.
2
pres-
CH ), 2.61 (t, J=8.0 Hz, 2H; CyH), 1.80 (d, J=10.0 Hz, 4H; CyH),
2
4
NI.
1
1
.68 (d, J=11.6 Hz, 4H; CyH), 1.55 (d, J=12.4 Hz, 2H; CyH), 1.08–
.23 (m, 8H; CyH), 1.00 ppm (t, J=12.0 Hz, 2H; CyH); C NMR
[
1
3
(100 MHz, CDCl , TMS): d=170.87 (ArC), 149.73 (ArC), 137.86 (ArC),
3
1
30.02 (ArC), 127.70 (ArC), 127. 48 (ArC), 64.90 (PhCH ), 64.54
2
Conclusion
(PhCH ), 60.43 (CyC), 30.51 (CyC), 25.75 (CyC), 25.58 ppm (CyC); ele-
2
In summary, a series of organobismuth complexes 1–11 were
synthesized and structurally characterized. As a result of the
cooperative action of the two bismuth atoms of sulfur-bridged
binuclear organobismuth complexes 4–6, these compounds
showed high catalytic efficiency towards the synthesis of cyclic
mental analysis (%) calcd. for C40
found: C 48.47, H 4.82, N 2.74.
H46Bi N O: C 48.59, H 4.69, N 2.83;
2 2
1
[
{PhN(CH C H ) Bi} O] (3): H NMR (400 MHz, CDCl , TMS): d=8.33
2
6
4
2
2
3
(d, J=7.0 Hz, 4H; ArH), 7.36 (t, J=7.0 Hz, 4H; ArH), 7.31 (d, J=
7
.0 Hz, 4H; ArH), 7.12 (d, J=7.0 Hz, 4H; ArH), 7.15 (t, J=7.0 Hz,
carbonates from CO and epoxides, especially the complex 4. It
2
4H; ArH), 7.02 (d, J=10.5 Hz, 4H; ArH), 6.88 (t, J=7.0 Hz, 2H; ArH),
is expected that complex 4 will find broad catalytic applica-
tions in organic synthesis.
4.66 (d, J=14.5 Hz, 4H; ArCH ), 4.33 ppm (d, J=14.5 Hz, 4H;
ArCH2); C NMR (100 MHz, CDCl , TMS): d=172.41 (ArC), 149.03
3
2
13
ChemPlusChem 2012, 77, 404 – 410
ꢀ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chempluschem.org
407

S. Yin, C.-T. Au, W.-Y. Wong et al.
(
(
(
ArC), 147.02 (ArC), 137.81 (ArC), 134.91 (ArC), 130.82 (ArC), 130.34
ArC), 129.61 (ArC), 129.50 (ArC), 128.17 (ArC), 128.08 (ArC), 127.79
ArC), 123.24 (ArC), 118.61 (ArC), 118.06 (ArC), 62.76 (ArCH2),
indices [I>2s(I)], R =0.042, wR =0.111; R indices (all data), R =
1
2
1
0.0484, wR =0.1069. GOF=1.03.
2
6
1.31 ppm (ArCH ); elemental analysis (%) calcd. for C H Bi N O:
2 40 34 2 2
C 49.19, H 3.51, N 2.87; found: C 48.97, H 3.64, N 2.66.
Synthesis of air-stable organobismuth chlorides 7–9
The precursors [(R)N(CH C H ) BiCl] (7, R=tBu; 8, R=Cy; 9, R=Ph)
2
6
4 2
of complexes [{(R)N(CH C H ) Bi} S] (4, R=tBu; 5, R=Cy; 6, R=Ph)
2
6
4 2
2
were prepared according to the procedure described in the litera-
Synthesis of air-stable binuclear sulfur-bridged organobis-
muth complexes of LBi-S-BiL (4–6)
[6d]
ture.
A solution of N,N-bis(2-bromobenzyl)-2-methylpropan-2-
amine (41.1 g, 100.0 mmol) in Et O (300 mL) was added to solution
2
of nBuLi (2.5m in hexane, 81.6 mL, 204.0 mmol) at À608C. The mix-
ture was gradually warmed to RT over 3 h. The mixture was then
added to a mixture of BiCl (31.4 g, 102.0 mmol) in Et O (400 mL)
at À808C. The resulting mixture was stirred overnight, during
which the temperature was allowed to rise gradually to RT. The sol-
vent was removed under vacuum and the residue was subject to
A solution of Na S·9H O (2.402 g, 10.0 mmol) in H O (10 mL) was
2
2
2
added to a solution of 7 (0.456 g, 1.0 mmol) in toluene (20 mL).
After the mixture was stirred at 258C for 15 h, it settled into two
layers. After separation (in air), the organic layer was mixed with n-
hexane (1.0 mL) and the resulting solution was kept at 258C for
3
2
2
4 h for the generation of colorless crystals (538 mg, 99%). Single
extraction with toluene/brine (2m NH Cl; 250 mLꢂ3), and the in-
4
crystals suitable for X-ray diffraction were grown from a solution in
toluene/n-hexane (90:10).
soluble material was removed by filtration. The organic layer was
washed with deionized H O (450 mLꢂ3) and dried over anhydrous
2
MgSO . The solvent was removed under reduced pressure to leave
1
4
[
(
4
1
1
{tBuN(CH C H ) Bi} S] (4): H NMR (400 MHz, CDCl , TMS): d=8.98
2
6
4 2
2
3
brownish yellow oil. The residue was recrystallized from CH Cl /n-
2
2
d, J=7.2 Hz, 2H; ArH), 7.26 (m, 2H; Ph), 7.18 (t, J=5.2 Hz, 4H; Ph),
.42 (d, J=14.8 Hz, 2H; PhCH ), 3.83 (d, J=14.8 Hz, 2H; PhCH ),
.16 (s, 9H; tBu); C NMR (100 MHz, CDCl , TMS): d=150.99,
41.80, 139.80, 129.96, 128.26, 128.03, 59.10, 58.18, 27.60. elemen-
tal analysis (%) calc. for C H Bi N S: C 45.38, H 4.44, N 2.94; found:
C 45.40, H 4.40, N 2.93. Crystal data for 4·CH Cl : C H Bi Cl N S;
M =1037.66; Monoclinic; space group C2/c; a=17.131(1) ꢁ, b=
5.2797(9) ꢁ, c=16.2750(9) ꢁ; b=120.826(1)8; V=3658.1(4) ꢁ ; T=
hexane (90:10) to give compound 7 in the form of colorless crys-
tals (43.06 g, 87%).
2
2
1
3
3
1
[
tBuN(CH C H ) BiCl] (7): m.p. 265–2668C; H NMR (400 MHz,
2
6
4 2
36
42
2
2
CDCl , TMS): d=8.63 (d, J=7.2 Hz, 2H; ArH), 7.48 (t, J=7.6 Hz, 2H,
3
2
2
37 44
2
2
2
ArH), 7.40 (d, J=7.2 Hz, 2H, ArH), 7.32 (d, J=7.6 Hz, 2H, ArH), 4.50
r
(
1
d, J=15.2 Hz, 2H; ArCH ), 4.11 (d, J=15.2 Hz, 2H; ArCH2),
.32 ppm (s, 9H, tBu); C NMR (100 MHz, CDCl , TMS): d=170.73
3
3
2
1
1
0
13
73(2) K; Z=4; Reflections collected/unique, 10487/4351, Rint
.031; Final R indices [I>2s(I)], R =0.041, wR =0.118; R indices (all
data), R =0.0447, wR =0.116. GOF=1.06.
=
(
(
ArC), 151.00 (ArC), 138.27 (ArC), 130.73 (ArC), 128.17 (ArC), 127.34
1
2
ArC), 60.20 (ArCH ), 60.00 (tBuC), 27.67 ppm (CH ); elemental anal-
2
3
1
2
ysis (%) calcd. for C H BiClN: C 43.60, H 4.27, N 2.83; found:
18
21
C 43.73, H 4.14, N 2.91.
CyN(CH C H ) BiCl] (8): m.p. 266–2698C; H NMR (400 MHz, CDCl ,
1
[
(
7
(
{(Cy)N(CH C H ) Bi} S] (5): H NMR (400 MHz, CDCl , TMS): d=9.03
2 6 4 2 2 3
d, J=7.2 Hz, 2H; ArH), 7.32–7.36 (dt, J=7.6, 2.4 Hz, 2H; ArH),
.16–7.27 (m, 4H; ArH), 4.12 (d, J=14.8 Hz, 2H; CH of PhCH ), 3.94
d, J=14.8 Hz, 2H; CH of PhCH ), 2.71–2.79 (tt, J=11.6, 2.8 Hz, 1H;
2 2
CH of Cy), 1.98 (d, J=12.8 Hz, 2H; CH of Cy), 1.79 (d, J=12.8 Hz,
H; CH of Cy), 1.61 (d, J=12.4 Hz, 1H; CH of Cy), 1.29–1.38 (dq,
2 2
J=12.4 Hz, 2H; CH of Cy), 1.15–1.24 (q, J=12.4 Hz, 2H; CH of
Cy), 1.08 (t, J=12.8, 12.4 Hz, 1H; CH of Cy); C NMR (100 MHz,
CDCl , TMS): d=158.47, 148.15, 139.39, 129.97, 127.29, 127.25,
3.01, 57.90, 29.78, 25.94; elemental analysis (%) calcd. for
C H Bi N S: C 47.81, H 4.61, N 2.79; found: C 47.85, H 4.63, N 2.75.
Crystal data for 5·PhCH : C H Bi N S; M =1096.94; Monoclinic;
space group C2/c; a=18.063(1) ꢁ, b=18.443(1) ꢁ, c=15.345(1) ꢁ;
b=125.407(1)8; V=4166.5(6) ꢁ ; T=173(2) K; Z=4; Reflections col-
lected/unique, 12963/5054, Rint =0.028; Final R indices [I>2s(I)],
R =0.0023, wR =0.050; R indices (all data), R =0.0386, wR =
1
[
2
6
4
2
3
2
2
TMS): d=8.62 (d, J=7.6 Hz, 2H; ArH), 7.39–7.48 (m, 4H; ArH), 7.31
t, J=7.6 Hz, 2H; ArH), 4.36 (d, J=15.2 Hz, 2H; ArCH ), 4.15 (d, J=
(
2
2
2
1
5.2 Hz, 2H; ArCH ), 2.92 (t, J=11.6 Hz, 1H; CyH), 1.99 (d, J=
2
2
11.6 Hz, 2H; CyH), 1.84 (d, J=12.8 Hz, 2H; CyH), 1.63 (d, J=
2
2
1
1
2.8 Hz, 1H; CyH), 1.23–1.42 (m, 4H; CyH), 1.12 ppm (t, J=12.8 Hz,
13
13
H; CyH); C NMR (100 MHz, CDCl , TMS): d=170.85 (ArC), 149.69
3
3
(
(
ArC), 138.15 (ArC), 130.80 (ArC), 128.05 (ArC), 127.63 (ArC), 64.81
6
ArCH ), 60.67 (CyN), 30.69 (CyC), 25.65 (CyC), 25.48 ppm (CyC); ele-
2
4
0
46
2
2
mental analysis (%) calcd. for C H BiClN: C 46.03, H 4.44, N 2.68;
20
23
3
47 54
2
2
r
found: C 45.99, H 4.48, N 2.67.
3
1
[
PhN(CH C H ) BiCl] (9): m.p. 257–2598C; H NMR (400 MHz, CDCl ,
2
6
4
2
3
TMS): d=8.60 (d, J=7.2 Hz, 2H; ArH), 7.51 (t, J=8.0 Hz, 4H, ArH),
1
2
1
2
7
7
2
.44 (d, J=7.2 Hz, 2H; ArH), 7.31 (t, J=7.2 Hz, 1H; ArH), 6.65 (t, J=
0
.0458. GOF=1.062.
.2 Hz, 2H; ArH), 6.47 (d, J=7.6 Hz, 2H; ArH), 4.76 (d, J=14.8 Hz,
1
3
H; ArCH2), 4.52 ppm (d, J=14.8 Hz, 2H; ArCH2);
C NMR
1
[
8
(
6
{PhN(CH C H ) Bi} S] (6): H NMR (400 MHz, CDCl , TMS): d=8.94–
.96 (dd, J=7.6, 1.2 Hz, 2H; ArH), 7.40–7.44 (m, 2H; ArH), 7.30–7.36
m, 4H; ArH), 7.19–7.25 (m, 2H; ArH), 7.08 (d, J=8.0 Hz, 2H; ArH),
.94 (t, J=7.6 Hz, 1H; ArH), 4.74 (d, J=15.2 Hz, 2H; ArCH ),
2
2
6
4
2
2
3
(100 MHz, CDCl , TMS): d=172.66 (ArC), 147.47 (ArC), 146.98 (ArC),
3
1
1
37.43 (ArC), 130.66 (ArC), 128.79 (ArC), 127.33 (ArC), 127.13 (ArC),
24.06 (ArC), 118.06 (ArC), 62.27 ppm (ArCH ); elemental analysis
2
(
%) calcd. for C H BiClN: C 46.57, H 3.32, N 2.72; found: C 46.49,
13
20 17
4
.43 ppm (d, J=15.2 Hz, 2H; ArCH2); C NMR (100 MHz, CDCl3,
H 3.36, N 2.62.
TMS): d=158.67 (ArC), 149.15 (ArC), 146.22 (ArC), 139.29 (ArC),
30.70 (ArC), 129.23 (ArC), 127.74 (ArC), 127.59 (ArC), 122.20 (ArC),
17.60 (ArC), 60.11 ppm (ArC); elemental analysis (%) calcd. for
C H Bi N S: C 48.39, H 3.45, N 2.82; found: C 49.23, H 3.54, N 2.83.
1
1
Synthesis of organobismuth complex 10
4
0
34
2
2
Crystal data for 6: C H Bi N S; M =992.71; Triclinic; space group
A mixture of oxide 1 was prepared as described above starting
from chloride 7 (3.00 g, 6.05 mmol). The resulting mixture was dis-
solved in methanol (100 mL) and stirred for 2 days at RT under ni-
trogen. Then the solvent was removed under reduced pressure
4
0
34
2
2
r
P ¯ı ; a=9.971(2) ꢁ, b=12.428 (2) ꢁ, c=15.189 (3) ꢁ; a=97.002 (3)
3
deg; b=99.712 (3)8, g=112.165 (3)8; V=1682.2 (5) ꢁ ; T=173(2) K;
Z=2; Reflections collected/unique, 8443/5729, R =0.040; Final R
int
4
08
www.chempluschem.org
ꢀ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemPlusChem 2012, 77, 404 – 410

Homogeneous Catalysis
and the resulting solid was recrystallized from CH Cl /n-hexane
2
2
Acknowledgements
(
90:10) to give methoxide complex 10 as colorless crystals.
This study was supported by the NSF of Hunan Province
1
[
tBuN(CH C H ) BiOMe] (10): H NMR (500 MHz, CDCl , TMS): d=
2
6
4
2
3
(
10JJ1003), the NSFC (Grant Nos. 21003040, 20973056), Nation-
8
7
4
1
.14 (dd, J=1.1, 7.5 Hz, 2H; ArH), 7.42 (dt, J=0.9, 7.3 Hz, 2H; ArH),
.29 (dd, J=0.6, 7.6 Hz, 2H; ArH), 7.21 (dt, J=1.3, 7.4 Hz, 2H; ArH),
.30 (d, J=15.2 Hz, 2H; ArCH ), 4.24 (s, 3H, OCH ), 3.89 (d, J=
al 863 Program of China (2009AA05Z319), the Program for New
Century Excellent Talents in Universities (NCET-10–0371), and the
Fundamental Research Funds for the Central Universities. C.-T.A.
and W.-Y.W. (both as HNU Adjunct Professors) thank Hong Kong
Baptist University for a Faculty Research Grant (FRG/08–09/II-09).
S.F.Y. thanks Dr. S. Shimada of AIST (Japan) for helpful discussion.
2
3
13
5.2 Hz, 2H; ArCH ),1.24 ppm (s, 9H, tBu); C NMR (125 MHz,
CDCl , TMS): d=171.17 (ArC), 150.13 (ArC), 135.66 (ArC), 129.47
ArC), 127.66 (ArC), 127.60 (ArC), 58.63 (ArCH ), 58.60 (ArCH ), 56.40
2 2
tBuC), 27.43 ppm (CH3); elemental analysis (%) calcd. for
2
3
(
(
C H BiNO: C 46.44, H 4.92, N 2.85; found: C 46.35, H 4.77, N 2.66.
1
9
24
Keywords: bridging ligands
·
carbon dioxide fixation
·
cooperative effects
heterocycles
·
homogeneous catalysis
·
oxygen
Synthesis of organobismuth complex 11
The organobismuth chloride 7 (2 mmol, 0.99 g) was treated with
NaSMe (100 mmol) in THF (30 mL) and stirred for 24 h at RT under
nitrogen. The solvent was removed under reduced pressure and
the resulting solid was dissolved with toluene, washed with water,
dried with Na SO , and evaporated, the residue was recrystallized
[1] a) R. M. Haak, S. J. Wezenberg, A. W. Kleij, Chem. Commun. 2010, 46,
2713–2723; b) R. K. Das, B. Saha, S. M. W. Rahaman, J. K. Bera, Chem.
Eur. J. 2010, 16, 14459–14468; c) C. Li, S. Cheng, M. Tjahjono, M.
Schreyer, M. Garland, J. Am. Chem. Soc. 2010, 132, 4589–4599; d) S.
Bonnet, J. H. van Lenthe, M. A. Siegler, A. L. Spek, G. van Koten R. J. M.
Klein Gebbink, Organometallics 2009, 28, 2325–2333; e) D. C. Powers,
M. A. L. Geibel, J. E. M. N. Klein, T. Ritter, J. Am. Chem. Soc. 2009, 131,
2
4
from benzene/n-hexane (90:10) to give complex 11 as colorless
crystals.
1
[
tBuN(CH C H ) BiSMe] (11): H NMR (400 MHz, CDCl , TMS): d=
2
6
4
2
3
17050–17051.
8
4
.59 (d, J=7.2 Hz, 2H; ArH), 7.32–7.37 (m, 2H; ArH), 7.27–7.29 (m,
H; ArH), 4.32 (d, J=13.2 Hz, 2H; ArCH ), 3.92 (d, J=13.6 Hz, 2H;
[
2] a) M. North, R. Pasquale, Angew. Chem. 2009, 121, 2990–2992; Angew.
Chem. Int. Ed. 2009, 48, 2946–2948; b) B. Y. Lee, H. Y. Kwon, S. Y. Lee,
S. J. Na, S.-i. Han, H. Yun, H. Lee, Y.-W. Park, J. Am. Chem. Soc. 2005, 127,
3031–3037.
2
13
ArCH ), 2.65 (s, 3H, SCH ), 1.26 ppm (s, 9H, tBu); C NMR (125 MHz,
2
3
CDCl , TMS): d=151.94 (ArC), 149.65 (ArC), 138.95 (ArC), 130.10
3
(
ArC), 127.78 (ArC), 127.48 (ArC), 58.55 (ArCH ), 57.92 (ArCH ), 27.46
[3] a) J. Park, K. Lang, K. A. Abboud, S. Hong, Chem. Eur. J. 2011, 17, 2236–
2
2
2
9
2
245; b) S. J. Wezenberg, A. W. Kleij, Adv. Synth. Catal. 2010, 352, 85–
1; c) R. M. Haak, S. J. Wezenberg, A. W. Kleij, Chem. Commun. 2010, 46,
713–2723; d) Q.-X. Guo, Z.-J. Wu, Z.-B. Luo, Q.-Z. Liu, J.-L. Ye, S.-W. Luo,
(
tBu), 10.99 ppm (SMe); elemental analysis (%) calcd. for
C H BiNS: C 44.97, H 4.77, N 2.76; found: C 44.90, H 4.79, N 2.78.
Crystal data for 11: C H BiNS, M =507.43; Monoclinic, P21/c; a=
1
V=1842.2 (3) ꢁ ; T=293 (2) K; Z=4; Reflections collected/unique,
1
0
1
9
24
1
9
24
r
L.-F. Cun, L.-Z. Gong, J. Am. Chem. Soc. 2007, 129, 13927–13938.
4] a) H. J. Breunig, M. G. Nema, C. Silvestru, A. P. Soran, R. A. Varga, Dalton
Trans. 2010, 39, 11277–11284; b) H. J. Breunig, L. Kçenigsmann, E. Lork,
M. Nema, N. Philipp, C. Silvestru, A. Soran, R. A. Varga, R. Wagner, Dalton
Trans. 2008, 1831–1842; c) A. Fridrichovꢃ, T. Svoboda, R. Jambor, Z. Pa-
d e˘ lkovꢄ, A. Rꢅ zˇ i cˇ ka, M. Erben, R. Jirꢃsko, L. Dostꢃl, Organometallics
1.7670 (10) ꢁ, b=10.3890 (9) ꢁ, c=15.0885 (13) ꢁ, b=92.894 (2)8;
[
3
0954/3630; Rint =0.038, Final R indices [I>2s(I)], R =0.032, wR =
1
2
.079,; R indices (all data), R =0.038, wR =0.076. GOF=1.073.
1
2
2
ˇ
009, 28, 5522–5528; d) L. Dostꢃl, R. Jambor, A. Rꢅ zˇ i cˇ ka, R. Jirꢃsko, E.
Cernoskovꢃ, L. Benes, F. De Proft, Organometallics 2010, 29, 4486–4490;
e) S. Yin, J. Maruyama, T. Yamashita, S. Shimada, Angew. Chem. 2008,
120, 6692–6695; Angew. Chem. Int. Ed. 2008, 47, 6590–6593; f) S. Yin, S.
Shimada, Chem. Commun. 2009, 1136–1138.
ˇ
ˇ
Typical procedure for CO chemical fixation to cyclic carbo-
2
nates
The reactions were carried out in high-pressure stainless-steel auto-
claves (30 mL) equipped with a magnetic bar. In a typical reaction,
the reactor was charged with an appropriate amount of catalyst,
epoxide, and biphenyl (as internal standard for GC analysis). Then
[
5] a) H. Suzuki, Y. Matano, Organobismuth Chemistry, Elsevier, Amsterdam,
2
001; b) S. Shimada, O. Yamazaki, T. Tanaka, M. L. N. Rao, Y. Suzuki, M.
Tanaka, Angew. Chem. 2003, 115, 1889–1892; Angew. Chem. Int. Ed.
2003, 42, 1845–1848; c) M. Bao, T. Hayashi, S. Shimada, Organometallics
2007, 26, 1816–1822; d) A. P. Soran, C. Silvestru, H. J. Breunig, G. Balꢃzs,
J. C. Green, Organometallics 2007, 26, 1196–1203; e) M. Chovancovꢃ, R.
Jambor, A. Rꢅ zˇ i cˇ ka, R. Jirꢃsko, I. Cꢆsa rˇ ova, L. Dostꢃl, Organometallics
the reactor was fed with CO to a desired pressure, the autoclave
2
with its contents was heated to a designated temperature and
stirred for a designated period of time. Then the reactor was
2
009, 28, 1934–1941; f) L. Balazs, H. J. Breunig, E. Lork, A. Soran, C. Sil-
cooled to 08C in an ice/water bath, and the remaining CO was re-
2
vestru, Inorg. Chem. 2006, 45, 2341–2346; g) S. Shimada, J. Maruyama,
Y.-K. Choe, T. Yamashita, Chem. Commun. 2009, 6168–6170.
leased using an aspirator and absorbed in an aqueous solution sa-
turated with K CO . The resulting product mixture was analyzed by
2
3
[
6] a) R. Qiu, Y. Qiu, S. Yin, X. Xu, S. Luo, C.-T. Au, W.-Y. Wong, S. Shimada,
Adv. Synth. Catal. 2010, 352, 153–162; b) R. Qiu, Y. Qiu, S. Yin, X. Song,
Z. Meng, X. Xu, X. Zhang, S. Luo, C.-T. Au, W.-Y. Wong, Green Chem.
2010, 12, 1767–1771; c) R. Qiu, S. Yin, X. Zhang, J. Xia, X. Xu, S. Luo,
Chem. Commun. 2009, 4759–4761; d) X. Zhang, J. Xia, H. Yan, S. Luo, S.
Yin, C.-T. Au, W.-Y. Wong, J. Organomet. Chem. 2009, 694, 3019–3026;
e) R. Qiu, S. Yin, X. Song, Z. Meng, Y. Qiu, N. Tan, X. Xu, S. Luo, F. Dai, C.-
T. Au, W.-Y. Wong, Dalton Trans. 2011, 40, 9482–9489.
GC-MS using an Agilent 6890–5973 MSD GC-MS spectrometer and
1
by H NMR spectroscopy using an INOVA 400 MHz NMR spectrome-
ter with TMS as internal standard. All the products were quantita-
tively analyzed using an Agilent 6890N gas chromatograph
equipped with a FID and Rtx-wax capillary column (30 mꢂ
0
.25 mmꢂ0.25 mm); analysis method: the internal standard
method, analysis conditions: injector temperature 2508C, detector
[
7] a) A. Decortes, A. M. Castilla, A. W. Kleij, Angew. Chem. 2010, 122,
temperature 2508C, the oven temperature was programmed
10016–10032; Angew. Chem. Int. Ed. 2010, 49, 9822–9837; b) M. R.
À1
(
maintained at 408C for 2 min, heated (158Cmin ) to 2208C and
Kember, A. Buchard, C. K. Williams, Chem. Commun. 2011, 47, 141–163;
c) M. North, R. Pasquale, C. Young, Green Chem. 2010, 12, 1514–1539.
1
maintained 10 min). All H NMR data of desired products were con-
firmed using the spectroscopic database for organic compounds
SDBS.
[8] a) W. Clegg, R. W. Harrington, M. North, R. Pasquale, Chem. Eur. J. 2010,
16, 6828–6843; b) W. Clegg, R. W. Harrington, M. North, P. Villuendas, J.
ChemPlusChem 2012, 77, 404 – 410
ꢀ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chempluschem.org
409

S. Yin, C.-T. Au, W.-Y. Wong et al.
Org. Chem. 2010, 75, 6201–6207; c) J. Melꢇndez, M. North, P. Villuendas,
C. Young, Dalton Trans. 2011, 40, 3885–3902.
9] a) R. Qiu, X. Xu, Y. Li, G. Zhang, L. Shao, D. An, S. Yin, Chem. Commun.
2 2 3
[11] CCDC 824590 (4·CH Cl ), 824591 (5·PhCH ), 824592 (6), and 856754 (11)
contain the supplementary crystallographic data for this paper. These
data can be obtained free of charge from The Cambridge Crystallo-
graphic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
[12] SAINT+, version 6.02a, Bruker Analytical X-ray System, Inc., Madison,
WI, 1998.
[
2009, 1679–1681; b) R. Qiu, Y. Zhu, X. Xu, Y. Li, L. Shao, X. Ren, X. Cai,
D. An, S. Yin, Catal. Commun. 2009, 10, 1889–1892; c) R. Qiu, G. Zhang,
Y. Zhu, X. Xu, L. Shao, Y. Li, D. An, S. Yin, Chem. Eur. J. 2009, 15, 6488–
6
494; d) R. Qiu, G. Zhang, X. Xu, K. Zou, L. Shao, D. Fang, Y. Li, A. Orita,
[13] G. M.Sheldrick, SADABS, Empirical Absorption Correction Program, Uni-
versity of Gçttingen, Germany, 1997.
[14] G. M. Sheldrick, SHELXTLTM, Reference Manual, version 5.1, Madison,
WI, 1997.
R. Saijo, H. Mineyama, T. Suenobu, S. Fukuzumi, D. An, J. Otera, J. Orga-
nomet. Chem. 2009, 694, 1524–1528; e) R. Qiu, Y. Li, L. Shao, X. Xu, G.
Zhang, D. An, Synth. Commun. 2010, 40, 3309–3314; f) G. Zhang, R.
Qiu, X. Xu, H. Zhou, Y. Kuang, S. Chen, Synth. Commun. 2012, 42, 858–
8
64; g) R. Qiu, G. Zhang, X. Ren, X. Xu, R. Yang, S. Luo, S. Yin, J. Organo-
met. Chem. 2010, 695, 1182–1188.
10] T. Sakakura, J.-C. Chio, H. Yasuda, Chem. Rev. 2007, 107, 2365–2387.
Received: February 11, 2012
[
Published online on March 14, 2012
4
10
www.chempluschem.org
ꢀ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemPlusChem 2012, 77, 404 – 410