Cationic palladium(II) complexes of phosphine-sulfonamide ligands: Synthesis, characterization, and catalytic ethylene oligomerization

Article abstract of DOI:10.1021/om5004094

A series of cationic palladium(II) complexes bearing phosphine-sulfonamide ligands, [(P,O)PdMe(lutidine)][SbF₆], were synthesized and used for catalytic ethylene oligomerization. The molecular structure of the complex {[N,N-dicyclohexyl-2-(diphenylphosphanyl)benzenesulfonamide]PdMe(lutidine)} [SbF₆] shows that the phosphorus atom and the oxygen atom coordinate to the palladium center. The ethylene oligomerization behavior is greatly influenced by the phosphino substituents, while the substituents on sulfonamide show only minimal effects. Complexes containing the diphenylphosphanyl group are highly selective for ethylene dimerization, affording 1-butene exclusively with moderate activity. The bulkier bis(2-methoxyphenyl)phosphanyl group leads to higher activity and gives α-olefins containing mainly 1-butene and 1-hexene, with a 1-hexene content of up to 35%. The palladium complexes bearing alkyl phosphino substituents give 1-butene and 1-hexene as the major products; a small amount of 2-butene (<5%) was observed, suggesting the occurrence of chain walking. The addition of B(C₆F₅)₃ greatly enhances the catalytic activity. Experimental results suggest that the increase in activity is likely due to the abstraction of lutidine, not from the coordination of B(C₆F₅)₃ to the sulfonamide oxygen atom.

Full text of DOI:10.1021/om5004094

Article
pubs.acs.org/Organometallics
Cationic Palladium(II) Complexes of Phosphine−Sulfonamide
Ligands: Synthesis, Characterization, and Catalytic Ethylene
Oligomerization
Yanlu Zhang,† Yanchun Cao,† Xuebing Leng,† Changle Chen,*,‡ and Zheng Huang*,†
†The State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, 345 Lingling Road,
Shanghai 200032, People’s Republic of China
‡CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science & Engineering, University of Science and
Technology of China, Hefei 230026, People’s Republic of China
S
* Supporting Information
ABSTRACT: A series of cationic palladium(II) complexes bearing phosphine−sulfonamide ligands, [(P,O)PdMe(lutidine)]-
[SbF6], were synthesized and used for catalytic ethylene oligomerization. The molecular structure of the complex {[N,N-
dicyclohexyl-2-(diphenylphosphanyl)benzenesulfonamide]PdMe(lutidine)}[SbF6] shows that the phosphorus atom and the
oxygen atom coordinate to the palladium center. The ethylene oligomerization behavior is greatly influenced by the phosphino
substituents, while the substituents on sulfonamide show only minimal effects. Complexes containing the diphenylphosphanyl
group are highly selective for ethylene dimerization, affording 1-butene exclusively with moderate activity. The bulkier bis(2-
methoxyphenyl)phosphanyl group leads to higher activity and gives α-olefins containing mainly 1-butene and 1-hexene, with a
1-hexene content of up to 35%. The palladium complexes bearing alkyl phosphino substituents give 1-butene and 1-hexene as the
major products; a small amount of 2-butene (<5%) was observed, suggesting the occurrence of chain walking. The addition of
B(C6F5)3 greatly enhances the catalytic activity. Experimental results suggest that the increase in activity is likely due to the
abstraction of lutidine, not from the coordination of B(C6F5)3 to the sulfonamide oxygen atom.
but their catalytic behavior was not reported.7 Jordan and co-
INTRODUCTION
■
workers synthesized neutral NHC−arenesulfonate palladium
Late-transition-metal-catalyzed olefin polymerization and oli-
gomerization have attracted tremendous attention since the
discovery of α-diimine Ni(II) and Pd(II) catalysts by Brookhart
complexes (B2; Chart 1), which were not active for ethylene
polymerization.8 Piers and Jordan have independently reported
and of phenoxyminato Ni(II) catalysts by Grubbs.1−3 Follow-
ing the establishment of the well-known SHOP process,4 a
large number of (P,O)-type ligands have been developed for
olefin polymerization and oligomerization.5 Recently, neutral
Pd(II) catalysts with phosphine−sulfonate ligands have been
widely reported for the copolymerization of ethylene with a
variety of polar vinyl monomers to form functionalized linear
copolymers (A; Chart 1).6 These anionic (P,O)− ligands con-
tain a strong σ-donating phosphine and a very weak σ-donating
sulfonate group. The electron-unsymmetric feature of these
ligands was believed to inhibit β-H (X) elimination, leading to
the formation of linear polymers, as well as the incorporation of
polar vinyl monomers in ethylene polymerization.6i Some other
ligands with a strong/weak σ-donor framework similar to
that of phosphine−sulfonate have also been developed. For
example, Nozaki and co-workers described the preparation of
neutral NHC−sulfonate palladium complexes (B1; Chart 1),
the synthesis of bidentate trifluoroborate−phosphine palladium
complexes (C; Chart 1), which dimerize ethylene to butenes
with low activity.9 Brookhart and Nozaki reported the synthesis
of neutral Ni(II) and Pd(II) catalysts with phosphine−
sulfonamide ligands (D1 and D2; Chart 1) in patents. The
Ni(II) catalysts catalyzed ethylene oligomerization, and the
Pd(II) catalyst can copolymerize methyl acrylate and ethylene
at 80 °C.10 Brookhart and co-workers reported the synthesis of
low-molecular-weight polyethylene catalyzed by cationic Pd(II)
complexes with bulky phenacyldi-tert-butylphosphine ligands
(E1; Chart 1).11 Recently, Nozaki and co-workers reported
the synthesis of cationic Pd(II) catalysts with bis-phosphine
monoxide ligands (E2, Chart 1), which exhibit good activity for
Received: April 17, 2014
Published: July 16, 2014
© 2014 American Chemical Society
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Chart 1. Neutral and Cationic Pd(II) Catalysts with Strong/Weak σ Donors
the copolymerization of ethylene with a variety of polar vinyl
monomers.12
new ligands and palladium complexes were characterized by
elemental analysis and NMR spectroscopy.
The molecular structure of 4a was determined by X-ray
diffraction analysis (Figure 1), which shows that the palladium
center is coordinated to the phosphorus atom and one of the
sulfonamide oxygen atoms. The geometry at palladium is
square planar, with the methyl ligand cis to the phosphine
group. The (P,O)Pd chelate ring adopts a puckered con-
formation, with one P-Ph group occupying a pseudoaxial
position and the other a pseudoequatorial position. The Pd−O
distance (2.2160 Å) is longer than those observed in both E2
(2.119 Å) and phosphine−sulfonate palladium complexes (A in
Chart 1: 2.159 Å for R = MeO-Ph, L = lut; 2.156 Å for R = Cy,
L = lut; 2.177 Å for R = Et-Ph, L = py).6d,f,h The Pd−P distance
(2.2310 Å) is similar to those in phosphine−sulfonate
palladium complexes (2.234 Å for R = MeO-Ph, L = lut;
2.234 Å for R = Cy, L = lut; 2.231 Å for R = Et-Ph, L = py).6d,f,h
The coordination of the sulfonamide group makes the S(1)−
O(1) distance (1.464 Å) slightly longer than that of S(1)−
O(2) (1.436 Å). The Pd−N distance (2.123 Å) is slightly
shorter than the average Pd−N distance (2.133 Å) observed in
other Pd−lutidine complexes.6d,e,7
Oligomerization of Ethylene by Cationic Palladium(II)
Complexes. The reactivity of the cationic palladium(II)
complexes with ethylene was studied. The results are
summerized in Table 1. All of these cationic phosphine−
sulfonamide palladium(II) complexes can oligomerize ethylene
mainly to α-olefins with moderate activity. The selectivity and
activity of the oligomerization are greatly influenced by the
substituents on the phosphorus atom, while the substituents in
the sulfonamide group show only minimal effects. Ethylene
oligomerization with the catalysts bearing aryl phosphino
substituents exclusively forms α-olefins. Specifically, when the
aryl group is phenyl (4a,e), 1-butene is the only product
(entries 1 and 8). The catalyst with the bulkier o-OMePh group
(4b) generates α-olefins containing mainly 1-butene and
1-hexene, with 35.2% of 1-hexene (entry 2). This suggests
that steric hindrance at the ortho position of the phenyl group
Inspired by these studies, we decided to investigate the
ethylene polymerization/oligomerization behavior of cationic
Pd complexes bearing phosphine−sulfonamide ligands con-
taining unsymmetric strong/weak σ donors similar to the
widely studied phosphine−sulfonate ligands. Mahon et al. have
reported the synthesis of the two phosphine−sulfonamide
ligands 2a,c, and the combination of these ligands with Pd
precursors was used in Suzuki and amination cross-coupling
reactions.13 However, the Pd complexes of the phosphine−
sulfonamide ligands have never been reported for ethylene
polymerization or oligomerization. Herein, we report the
preparation of a series of cationic Pd(II) methyl catalysts
with phosphine−sulfonamide (P, O) ligands (4; Chart 1).
These complexes can catalyze the oligomerization of ethylene
to selectively form α-olefins.
RESULTS AND DISCUSSION
■
Synthesis and Characterization of Cationic Palladium-
(II) Complexes. The synthetic routes for the phosphine−
sulfonamide (P,O) ligands 2a−f and the cationic palladium(II)
complexes 4a−f are illustrated in Scheme 1. Ligand 2b was
prepared by refluxing a THF mixture of (o-OMePh)2P-OMe
with the lithiated salt of sulfonamide 1a, using the procedure
developed by Drent.6b Pure 2b was obtained by chromatog-
raphy (light petroleum/ethyl acetate 8/1) in 17% yield. The
reaction of sulfonamide 1a or 1b with 1 equiv of nBuLi in THF
followed by the addition of R2PCl led to the formation of
ligands 2a,c−f in 35−91% yield.13 Attempts to synthesize the
ligand with a tBu2P group failed, presumably due to steric
effects.
The reactions of ligands 2a−f with (COD)PdMeCl (COD =
1,5-cyclooctadiene) yielded phosphine−sulfonamide complexes
(P,O)PdMeCl (3a−f), which reacted with silver hexafluor-
oantimonate and 2,6-lutidine to generate the cationic palladium
complexes 4a−f in good isolated yields (65−79%). All of the
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Scheme 1
Table 1. Oligomerization of Ethylene with Cationic
Palladium Complexes
c
selectivity (%)
a
b
entry
cat.
T (°C) P (psi) TOF
1-C4
1-C6 1-C8
1
2
3
4
5
4a
4b
4b
4b
4b
4c
4d
4e
4f
50
50
50
25
80
50
50
50
50
50
50
50
300
300
150
150
150
300
300
300
300
300
300
300
2.6
100
7.4
5.6
61.0
66.6
70.2
84.0
84.3
90.8
100
35.2
30.8
29.8
14.9
12.4
6.4
3.8
2.6
0.4
8.0
1.1
d
6
9.7
e
7
4.9
8
2.1
f
9
7.7
92.9
67.5
63.4
64.1
3.0
32.5
36.6
35.9
g
10
4b
4b
36.0
51.9
36.1
<1
h
Figure 1. ORTEP plot of complex 4a (C39H50Cl2F6N2O2PPdSSb·
11
<1
<1
−
CH2Cl2). Hydrogen atoms and SbF6 and CH2Cl2 groups have been
12
3b + AgSbF6
omitted for clarity. Thermal ellipsoids are presented at the 30%
probability level. Selected bond lengths (Å) and angles (deg): Pd(1)−
C(1) 2.034(3), Pd(1)−N(1) 2.123(2), Pd(1)−O(1) 2.216(19),
Pd(1)−P(1) 2.231(7), S(1)−O(1) 1.464(2), S(1)−O(2) 1.436(2);
O(1)−Pd(1)−P(1) 96.49(5), C(14)−P(1)−Pd(1) 110.10(9),
C(15)−C(14)−P(1) 123.6(2), C(14)−C(15)−S1 119.39(19),
O(1)−S(1)−C(15) 106.4(12).
a
Conditions: 5 μmol of cat., 100 mL of CH2Cl2, 30 min reaction time.
b
c
In units of 103 (mol of ethylene)/((mol of Pd) h). 1-Cn (%) =
1-Cn/oligomers × 100, detected by GC. n-Heptane was used as
d
e
f
internal standard. 3.3% 2-butene. 2.8% 2-butene. 4.1% 2-butene.
g
h
Addition of 1 equiv of B(C6F5)3. Addition of 2 equiv of B(C6F5)3.
Catalysts with a phenyl substituent on the phosphorus atom
has a dramatic effect on retarding the chain transfer process.
Both increasing and reducing the reaction temperature reduces
the selectivity of 1-hexene (entries 3−5). Finally, the catalysts
with alkyl phosphino substituents (4c,d,f) lead to mainly
1-butene, some 1-hexene, and a small percentage of 2-butene
(entries 6, 7 and 9). This suggests the occurrence of chain
walking during the oligomerization.2b
(4a,e) give 1-butene with the highest selectivity, but with the
lowest activity (entries 1 and 8), while the catalyst with an
o-OMe-Ph substituent leads to a 2-fold increase in TOF
(entry 2). In contrast, catalysts with alkyl substituents on the
phosphorus atom (4c,d,f) show 1−3 times higher TOFs
(entries 6, 7, and 9). The reaction conditions such as ethylene
pressure and temperature also affect the activity. When the
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ethylene pressure is decreased from 300 to 150 psi (entry 2 vs
entry 3), the TOF decreases from 7.4 × 103 to 5.6 × 103 (mol
of ethylene)/((mol of Pd) h). Reducing the temperature from
50 to 25 °C (entry 3 vs entry 4) leads to a sharp decrease in
TOF from 5.6 × 103 to 0.4 × 103 (mol of ethylene)/((mol of
Pd) h). When the temperature is increased from 50 to 80 °C,
the TOF has a moderate increase (entry 3 vs 5).
products as 1-butene and 1-hexene. The addition of B(C6F5)3
was shown to greatly increase the oligomerization activity.
This effect is attributed to the abstract of lutidine, which would
compete with ethylene for the binding to palladium center
during oligomerization.
EXPERIMENTAL SECTION
■
The addition of 1 equiv of B(C6F5)3 results in a dramatic
increase in the TOFs from 7.4 × 103 to 36.0 × 103 (mol of
ethylene)/((mol of Pd) h) (entry 10 vs 2) without changing
the oligomer distribution. Interestingly, the addition of 2 equiv
of B(C6F5)3 leads to a further increase in TOFs without much
perturbation in the oligomer distribution (entry 11). B(C6F5)3
may act as a Lewis acid to abstract the lutidine in the cationic
palladium complex or coordinate to the sulfonamide oxygen
atom.14,15 During ethylene oligomerization, ethylene must
compete with lutidine to coordinate with the palladium(II)
center, which will reduce the activity of the catalyst. When 3b
was activated in situ by AgSbF6 (entry 12), oligomerization
results were obtained similar to those on catalysis by 4b with
the addition of 1 equiv of B(C6F5)3 (entry 10). Recently,
Jordan et al. showed that the binding of B(C6F5)3 to a sulfonate
oxygen of (phosphine−sulfonate)PdR catalysts results in a
40−80-fold increase in the rate of chain transfer in ethylene
polymerization.15 In one case, the molecular weight (Mn) of the
resulting polyethylene was reduced from 3000 to 170. In our
case, the ratio of 1-hexene to 1-butene was essentially not
changed (entries 10 and 11 vs entry 2) with the addition of
0, 1, or 2 equiv of B(C6F5)3, suggesting the presence of the
same catalytically active species. Therefore, the coordination of
B(C6F5)3 to the sulfonamide oxygen atom may be minimal
under our reaction conditions. The bulky dicyclohexylamino
substituent on the sulfonamide group can potentially prevent
the coordination of B(C6F5)3 to the oxygen atom.
General Considerations. Unless otherwise stated, all manipu-
lations were carried out under a dry argon or nitrogen atmosphere
using standard Schlenk techniques. Solvents were purified by
distillation over sodium benzophenone (diethyl ether, tetrahydrofuran,
toluene, n-hexane) and CaH2 (dichloromethane). CDCl3 and CD2Cl2
were purchased from Cambridge, dried with 4 Å molecular sieves, and
stored under nitrogen. Polymerization grade ethylene was used after
purification. PhSO2NCy2 (1a),13 PhSO2NMe2 (1b),13 ligands 2a,c,13
(o-OMePh)2P-OMe,6b and (COD)PdMeCl14 were prepared accord-
ing to previously reported procedures. All other reagents and solvents
were purchased from commercial sources and used without further
purification.
NMR spectra were recorded on Agilent 400 MHz and Varian
Mercury 400 MHz instruments. 1H NMR chemical shifts were
referenced to residual protio solvent peaks or the tetramethylsilane
signal (0 ppm), and 13C NMR chemical shifts were referenced to the
solvent resonance. 31P NMR chemical shifts were referenced to an
external H3PO4 standard. GC-MS measurements were performed on a
Agilent 7890A gas chromatograph coupled to an Agilent 5975C inert
mass-selective detector. GC analyses were carried out on an Agilent
7890A gas chromatograph equipped with a flame ionization detector.
Elemental analyses were carried out by the Analytic laboratory
of Shanghai Institute of Organic Chemistry (CAS). IR data were
obtained on a Bruker TENSOR 27 instrument.
Preparation of the Ligands and Palladium(II) Complexes.
Ligand 2b.
n-BuLi in n-hexane (2.5 mL, 6.0 mmol) was added dropwise to a
solution of PhSO2NCy2 (1a; 6.0 mmol, 2.0 g) in 40 mL of THF
at −78 °C. After the mixture was stirred for 3 h at room temperature,
a solution of 6 mmol of (o-OMePh)2P-OMe (1.65 g) in 20 mL of
THF was added dropwise at room temperature and the reaction
mixture was stirred under reflux for 3 days. Then the reaction mixture
was quenched with saturated NH4Cl (100 mL) and diluted with
150 mL of CH2Cl2. The organic layer was separated, and the aqueous
phase was extracted with CH2Cl2 (50 mL). The combined organic
layers were dried over anhydrous MgSO4, filtered, and concentrated to
give a light yellow solid. The residue was chromatographed on a silica
gel column (ethyl acetate/petroleum ether 1/8, Rf = 0.55) to give pure
As discussed above, analogous phosphine−sulfonate palla-
dium complexes (A; Chart 1) and bis-phosphine monoxide
palladium complexes (E2; Chart 1) are highly active in ethylene
polymerization. This dramatic difference may be attributed
to the relatively weak electron donating ability of the
sulfonamide group in comparison with the sulfonate and
phosphine monoxide groups.9a This leads to an electron-
deficient palladium center, which makes the palladium−lutidine
coordination tighter. This is consistent with the shorter Pd−N
bond distance in 4a in comparison to the average Pd−N
distance observed in other Pd−lutidine complexes.6d,e,7 The
strong binding affinity of lutidine toward the Pd(II) center in 4
likely leads to the inhibition of the catalytic activity of olefin
oligomerization. The electron-deficient feature of the palladium
center may promote β-hydride elimination during chain
propagation and result in the formation of lower oligomers.16
1
2b in 17% yield (0.57 g). H NMR (400 MHz, CDCl3): δ 1.02−1.15
(2H, m, CH2), 1.17−1.35 (4H, m, CH2), 1.53−1.65 (2H, m, CH2),
1.66−1.90 (10H, m, CH2), 3.60−3.80 (2H, m, NCH), 3.70 (6H, s,
OCH3), 6.52−6.68 (1H, bs, Ar-H), 6.79−6.92 (4H, m, Ar-H), 7.01−
7.08 (1H, m, Ar-H), 7.24−7.34 (3H, m, Ar-H), 7.40 (1H, t, J = 7.8 Hz,
Ar-H), 8.08−8.14 (1H, m, Ar-H). 13C{1H} NMR (100 MHz, CDCl3):
δ 151.04 (d, J = 16.8 Hz), 146.91 (d, J = 25.0 Hz), 137.39 (d, J = 30.8
Hz), 135.21, 134.09, 130.95, 129.99 (d, J = 3.0 Hz), 129.86, 128.23,
125.83 (d, J = 16.6 Hz), 121.00, 110.31, 57.93 (d, J = 5.4 Hz), 55.49,
32.98, 26.63, 25.42. 31P{1H} NMR (162 MHz, CDCl3): δ −26.39 ppm.
Anal. Calcd for C32H40NO4PS: C, 67.94; H, 7.13; N, 2.48. Found: C,
68.16; H, 7.09; N, 2.50.
CONCLUSIONS
■
A series of cationic palladium(II) complexes with phosphine−
sulfonamide ligands were synthesized. These palladium com-
plexes can oligomerize ethylene mainly to α-olefins with
moderate activity. The longer Pd−O distance and shorter
Pd−N distance of 4a in comparison to the analogous palladium
complexes suggest an electron-deficient palladium center. This
might be the reason for the high chain transfer rates, resulting
in the formation of lower oligomers. Complexes with aryl
substituents on phosphine afford α-olefins exclusively, and
complexes with alkyl substituents on phosphine led to the
formation of a small portion of 2-butene with the main
Ligand 2d.
To a solution of PhSO2NCy2 (1a; 6.0 mmol, 2.0 g) in 40 mL of THF
was added dropwise 2.5 mL of a hexane solution of n-BuLi (6.0 mmol)
at −78 °C. After the mixture was stirred for 30 min, iPr2PCl (1.0 mL,
6.0 mmol) in 20 mL of THF was added dropwise to the reaction
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vessel. The reaction mixture was slowly warmed to room temperature
and was stirred overnight. After 20 h, the reaction mixture was
quenched with saturated degassed NH4Cl (100 mL). The organic layer
was separated, and the aqueous phase was extracted with Et2O
(50 mL). The combined organic layers were dried over anhydrous
MgSO4, filtered, and concentrated to give a white solid of 2d in 89%
yield (2.3 g). 1H NMR (400 MHz, CDCl3) δ 0.99 (3H, d, J = 7.0 Hz,
CH3), 1.02 (3H, d, J = 7.0 Hz, CH3), 1.05−1.30 (6H, m, CH2), 1.12
(3H, d, J = 7.0 Hz, CH3), 1.15 (3H, d, J = 7.0 Hz, CH3), 1.52−1.61
(2H, m, CH2), 1.66−1.80 (12H, m, CH2), 2.06−2.19 (2H, m, PCH),
3.55−3.67 (2H, m, NCH), 7.35−7.47 (2H, m, Ar-H), 7.56 (1H, d, J =
7.4 Hz, Ar-H), 8.03−8.09 (1H, m, Ar-H). 13C{1H} NMR (100 MHz,
CDCl3): δ 148.64 (d, J = 22.8 Hz), 138.02 (d, J = 35.2 Hz), 133.10 (d,
J = 2.0 Hz), 130.45, 129.74 (d, J = 3.6 Hz), 128.14, 57.82 (d, J = 5.4
Hz), 33.00, 26.59, 25.37, 24.69 (d, J = 17.0 Hz), 20.81 (d, J = 16.0
Hz), 19.27 (d, J = 16.6 Hz). 31P{1H} NMR (162 MHz, CDCl3): δ 4.71
ppm. Anal. Calcd for C24H40NO2PS: C, 65.87; H, 9.21; N, 3.20.
Found: C, 65.66; H, 9.38; N, 3.27.
Ligand 2a (1.7 mmol, 0.86 g) was dissolved in 30 mL of CH2Cl2.
To the colorless solution was added 1.7 mmol of (COD)PdMeCl
(0.47 g), forming a light yellow solution. The mixture was stirred for
3 h at room temperature. Removing the solvent in vacuo yielded a
light yellow solid. The solid was washed with hexane (2 × 10 mL) and
dried in vacuo for 30 min to give an off-white solid as the product (1.0
g, 93%). 1H NMR (400 MHz, CDCl3): δ 0.80 (3H, d, J = 2.7 Hz, Pd-
CH3), 0.92−1.16 (6H, m, CH2), 1.42−1.80 (14H, m, CH2), 3.10−3.22
(2H, m, CH), 7.11 (1H, t, J = 8.5 Hz, Ar-H), 7.32−7.55 (10H, m, Ar-
H), 7.62 (2H, t, J = 8.5 Hz, Ar-H), 7.88−7.96 (1H, m, Ar-H). 13C{1H}
NMR (100 MHz, CDCl3): δ 145.86 (d, J = 11.6 Hz), 135.56, 134.21
(d, J = 12.7 Hz), 131.93 (d, J = 5.0 Hz), 131.62 (d, J = 10.0 Hz),
131.28, 131.11, 130.90, 128.93 (d, J = 6.8 Hz), 128.67 (d, J =
11.0 Hz), 128.46, 127.95 (d, J = 12.8 Hz), 126.78. 31P{1H} NMR (162
MHz, CD2Cl2): δ 30.19 ppm. Anal. Calcd for C31H39ClNO2PPdS·
0.3CH2Cl2: C, 54.64; H, 5.80; N, 2.04. Found: C, 54.91; H, 6.05;
N, 1.98.
Complex 3b.
Ligand 2e.
To a solution of PhSO2NMe2 (1b; 11.0 mmol, 2.1 g) in 40 mL
of THF was added dropwise 4.6 mL of a hexane solution of n-BuLi
(11.0 mmol) at −78 °C. After the mixture was stirred for 30 min,
Ph2PCl (2.0 mL, 11.0 mmol) in 20 mL of THF was added dropwise to
the reaction vessel. The reaction mixture was slowly warmed to room
temperature and was stirred overnight. After 20 h, the reaction was
quenched with saturated degassed NH4Cl (100 mL). The organic layer
was separated, and the aqueous phase was extracted with degassed
Et2O (50 mL). The combined organic layers were dried over
anhydrous MgSO4, filtered, and concentrated to give a white solid.
The crude material was purified by flash chromatography with CH2Cl2
The same procedure as described for the synthesis of 3a was used.
Ligand 2b (0.4 g, 0.7 mmol) and (COD)PdMeCl (0.18 g, 0.7 mmol)
were used to give 3b (0.48 g, 95%) as a yellow solid. 1H NMR
(400 MHz, CD2Cl2): δ 0.58 (3H, d, J = 2.8 Hz, Pd-CH3), 0.98−1.12
(6H, m, CH2), 1.48−1.55 (2H, m, CH2), 1.60−1.85 (12H, m, CH2),
2.99−3.09 (2H, m, NCH), 3.64 (6H, s, OCH3), 6.94−7.06 (4H, m,
Ar-H), 7.33−7.48 (3H, m, Ar-H), 7.50−7.66 (4H, m, Ar-H), 7.88−
7.96 (1H, m, Ar-H). 13C{1H} NMR (100 MHz, CD2Cl2): δ 161.38 (d,
J = 2.9 Hz), 145.21 (d, J = 12.8 Hz), 137.50, 136.17 (d, J = 2.2 Hz),
134.31, 131.49 (d, J = 19.1 Hz), 131.35 (d, J = 35.9 Hz), 130.08 (d, J =
6.5 Hz), 121.80 (d, J = 11.3 Hz), 116.63, 116.11, 112.12 (d, J = 4.4
Hz), 59.12, 56.13, 32.52, 27.00, 25.72, −0.25. 31P{1H} NMR (162
MHz, CD2Cl2): δ 22.72 ppm. Anal. Calcd for C33H43ClNO4PPdS·
CH2Cl2: C, 50.57; H, 5.62; N, 1.73. Found: C, 50.69; H, 5.37; N, 2.17.
Complex 3c.
1
as eluent to yield ligand 2e as a white solid in 67% yield (2.7 g). H
NMR (400 MHz, CDCl3): δ 2.63 [6H, s, N(CH3)2], 7.13−7.17 (1H,
m, Ar-H), 7.17−7.23 (4H, m, Ar-H), 7.30−7.35 (6H, m, Ar-H), 7.41−
7.51 (2H, m, Ar-H), 8.08−8.13 (1H, m, Ar-H). 13C{1H} NMR (100
MHz, CDCl3): δ 142.31 (d, J = 24.2 Hz), 137.92 (d, J = 29.8 Hz),
136.88, 136.74, 133.55 (d, J = 20.6 Hz), 132.32, 130.66 (d, J =
3.4 Hz), 128.88, 128.68, 128.46 (d, J = 6.8 Hz), 36.66 (d, J = 4.92 Hz).
31P{1H} NMR (162 MHz, CDCl3): δ −9.09 ppm. Anal. Calcd for
C20H20NO2PS: C, 65.03; H, 5.46; N, 3.79. Found: C, 64.76; H, 5.49;
N, 3.80.
The same procedure as described for the synthesis of 3a was used.
Ligand 2c (0.62 g, 1.2 mmol) and (COD)PdMeCl (0.32 g, 1.2 mmol)
were used to give 3c (0.75 g, 93%) as a yellow solid. 1H NMR
(400 MHz, CDCl3): δ 0.98 (3H, d, J = 2.2 Hz, Pd-CH3), 1.02−1.32
(16H, m, CH2), 1.51−2.02 (22H, m, 22CH2, 2PCH), 2.10−2.30 (4H,
m, CH2), 3.15−3.30 (2H, m, NCH), 7.58−7.68 (2H, m, Ar-H), 7.76
(1H, t, J = 7.4 Hz, Ar-H), 7.91 (1H, dm, J = 7.6 Hz, Ar-H). 13C{1H}
NMR (100 MHz, CDCl3): δ 147.48 (d, J = 9.6 Hz), 133.91, 131.57 (d,
J = 4.4 Hz), 130.34, 128.38 (d, J = 29.2 Hz), 127.72 (d, J = 5.0 Hz),
59.19, 35.40 (d, J = 24.4 Hz), 31.92, 31.31, 29.23 (d, J = 4.0 Hz),
28.36, 26.71 (d, J = 2.2 Hz), 26.69 (d, J = 22.0 Hz), 26.21, 25.58,
24.84, 22.38, 13.88, −4.78. 31P{1H} NMR (162 MHz, CDCl3):
δ 33.72 ppm. Anal. Calcd for C31H51ClNO2PPdS·CH2Cl2: C, 50.60;
H, 7.03 N, 1.84. Found: C, 50.92; H, 7.43; N, 2.38.
Ligand 2f.
The same procedure as described for the synthesis of 2d was employed
to prepare 2f. PhSO2NMe2 (1b; 6.0 mmol, 1.1 g), n-BuLi in hexane
(2.5 mL, 6.0 mmol), and iPr2PCl (1.0 mL, 6 mmol) were used to yield
ligand 2f as a white solid (91%, 1.6 g). 1H NMR (400 MHz, CDCl3):
δ 0.89 [3H, d, J = 7.0 Hz, CH(CH3)2], 0.92 [3H, d, J = 7.0 Hz,
CH(CH3)2], 1.13 [3H, d, J = 7.0 Hz, CH(CH3)2], 1,17 [3H, d, J = 7.0
Hz, CH(CH3)2], 2.04−2.18 (2H, m, CH), 2.83 [6H, s, N(CH3)2],
7.44 (1H, td, J = 7.6, 0.8 Hz, Ar-H), 7.52 (1H, td, J = 7.4, 1.2 Hz, Ar-
H), 7.69 (1H, d, J = 7.6, Ar-H), 8.03 (1H, dm, J = 8.0, Ar-H). 13C{1H}
NMR (100 MHz, CDCl3): δ 144.10 (d, J = 23.8 Hz), 139.09 (d, J =
38.0 Hz), 134.13 (d, J = 2.5 Hz), 131.37, 130.41 (d, J = 4.2 Hz),
128.42, 37.48 (d, J = 7.2 Hz), 25.40 (d, J = 16.4 Hz), 20.32 (d, J =
13.4 Hz), 19.95 (d, J = 19.4 Hz). 31P{1H} NMR (162 MHz, CDCl3): δ
3.23 ppm. Anal. Calcd for C14H24NO2PS: C, 55.79; H, 8.03; N, 4.65.
Found: C, 55.73; H, 8.03; N, 4.64.
Complex 3d.
The same procedure as described for the synthesis of 3a was used.
Ligand 2d (0.40 g, 0.91 mmol) and (COD)PdMeCl (0.24 g, 0.91
mmol) were used to give 3d (0.53 g, 94%) as a yellow solid. 1H NMR
(400 MHz, CDCl3): δ 0.98 (3H, d, J = 2.2 Hz, Pd-CH3), 1.05−1.40
(6H, m, CH2), 1.18−1.28 (12H, m, CH3), 1.50−1.60 (2H, m, CH2),
1.72−1.87 (8H, m, CH2), 1.92−2.02 (4H, m, CH2), 2.46−2.58
Complex 3a.
3742
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Article
(2H, m, PCH), 3.17−3.30 (2H, m, NCH), 7.58−7.68 (2H, m, Ar-H),
7.69−7.76 (1H, m, Ar-H), 7.88−7.96 (1H, m, Ar-H). 13C{1H} NMR
(100 MHz, CDCl3): δ 147.15 (d, J = 9.2 Hz), 133.58, 131.70 (d, J =
4.0 Hz), 130.96, 128.39 (d, J = 27.2 Hz), 127.99, 59.11, 31.93, 26.16,
25.74 (d, J = 24.4 Hz), 24.78, 18.76 (d, J = 5.6 Hz), 18.18, −5.42.
31P{1H} NMR (162 MHz, CDCl3): δ 40.22 ppm. Anal. Calcd for
C25H43ClNO2PPdS: C, 50.51; H, 7.29; N, 2.36. Found: C, 50.30; H,
7.28; N, 2.34.
132.99 (d, J = 2.0 Hz), 132.92 (d, J = 2.4 Hz), 130.54, 130.18 (d, J =
11.4 Hz), 128.81 (d, J = 6.6 Hz), 128.44, 127.90, 123.77 (d, J =
3.2 Hz), 60.54, 32.98, 26.97, 26.87, 25.67, 0.78. 31P{1H} NMR (162
MHz, CD2Cl2): δ 28.39 ppm. Anal. Calcd for C38H48F6N2O2PPdSSb·
CH2Cl2: C, 44.16; H, 4.78; N, 2.67. Found: C, 44.40; H, 4.78; N, 2.66.
Complex 4b.
Complex 3e.
The same procedure as described for the synthesis of 4a was used.
The complex 3b (0.35 g, 0.48 mmol), lutidine (55 μL, 0.48 mmol),
and AgSbF6 (0.16 g, 0.48 mmol) were used to give 4b (0.37 g, 75%) as
a white solid. 1H NMR (400 MHz, CD2Cl2): δ 0.39 (3H, d, J = 3.0 Hz,
Pd-CH3), 0.85−1.09 (6H, m, CH2), 1.42−1.70 (14H, m, CH2), 2.96−
3.06 (2H, m, NCH), 3.10 (6H, s, py-H), 3.73 (6H, s, OCH3), 7.05−
7.13 (4H, m, 3Ar-H, py-H), 7.23−7.28 (2H, m, py-H), 7.35−7.76
(8H, m, Ar-H), 7.85−7.92 (1H, m, Ar-H). 13C{1H} NMR (100 MHz,
CD2Cl2): δ 161.36, 159.45, 149.68, 145.02 (d, J = 13.0 Hz), 139.90,
136.85, 135.08, 132.68 (d, J = 6.6 Hz), 132.16 (d, J = 1.8 Hz), 130.58,
130.12, 128.93 (d, J = 7.2 Hz), 123.56 (d, J = 3.4 Hz), 122.02 (d, J =
11.2 Hz), 114.95, 114.30, 112.29 (d, J = 4.8 Hz), 111.78, 59.95, 56.07,
32.59, 26.86, 26.72, 25.69, 0.58. 31P{1H} NMR (CD2Cl2): δ 18.81
ppm. Anal. Calcd for C39H49F6N2O4PPdSSb: C, 46.15; H, 4.87, N,
2.76. Found: C, 46.22; H, 5.16; N, 2.70.
The same procedure as described for the synthesis of 3a was used.
Ligand 2e (0.53 g, 1.4 mmol) and (COD)PdMeCl (0.37 g, 1.4 mmol)
were used to give 3e (0.53 g, 92%) as a light yellow solid. H NMR
1
(400 MHz, CDCl3): δ 0.88 (3H, d, J = 3.8 Hz, Pd-CH3), 3.04 [6H, s,
N(CH3)2], 7.10 (1H, t, J = 8.8 Hz, Ar-H), 7.42−7.55 (10H, m, Ar-H),
7.64 (1H, t, J = 7.6 Hz, Ar-H), 7.71 (1H, t, J = 7.6 Hz, Ar-H), 8.25−
8.31 (m, 1H, Ar-H). 13C{1H} NMR (100 MHz, CD2Cl2): δ 138.36 (d,
J = 12.6 Hz), 137.39 (d, J = 1.6 Hz), 135.29, 135.15 (d, J = 5.8 Hz),
135.01 (d, J = 12.8 Hz), 133.98 (d, J = 6.4 Hz), 132.27 (d, J = 2.0 Hz),
132.01 (d, J = 2.6 Hz), 130.21, 129.66, 129.54 (d, J = 11.4 Hz), 40.91,
3.24 (d, J = 2.0 Hz). 31P{1H} NMR (126 MHz, CDCl3): δ 29.93 ppm.
Anal. Calcd for C21H23ClNO2PPdS: C, 47.92; H, 4.40 N, 2.66. Found:
C, 47.37; H, 4.41; N, 2.68.
Complex 4c.
Complex 3f.
The same procedure as described for the synthesis of 3a was used.
Ligand 2f (0.49 g, 1.3 mmol) and (COD)PdMeCl (0.34 g, 1.3 mmol)
were used to give 3f (0.60 g, 95%) as a light yellow solid. H NMR
The same procedure as described for the synthesis of 4a was used. The
complex 3c (0.20 g, 0.30 mmol), lutidine (35 μL, 0.30 mmol), and
AgSbF6 (0.10 g, 0.30 mmol) were used to give 4c (0.23 g, 79%) as a
1
(400 MHz, CDCl3): δ 1.08 (3H, d, J = 2.6, Pd-CH3), 1.19−1.30
[12H, m, CH(CH3)2], 2.58−2.70 (2H, m, CH), 3.00 [6H, s,
N(CH3)2], 7.71 (1H, tt, J = 7.6, 1.2, Ar-H), 7.76 (1H, td, J = 7.6,
1.4, Ar-H), 7.94 (1H, t, J = 7.0, Ar-H), 8.08 (1H, dm, J = 7.8, Ar-H).
13C{1H} NMR (100 MHz, CDCl3): δ 141.96 (d, J = 9.8 Hz), 134.64,
132.94 (d, J = 4.0 Hz), 131.44, 129.99, 128.94 (d, J = 25.6 Hz),
39.23, 25.87 (d, J = 25.4 Hz), 18.84 (d, J = 4.6 Hz), 18.33, −4.80.
31P{1H} NMR (162 MHz CDCl3): δ 38.67 ppm. Anal. Calcd for
C22H36F6N2O2PPdSSb: C, 34.51; H, 4.74; N, 3.66. Found: C, 34.26;
H, 4.88; N, 3.74.
1
white solid. H NMR (400 MHz, CD2Cl2): δ 0.68−0.73 (3H, m, Pd-
CH3), 0.96−1.46 (16H, m, CH2), 1.52−1.95 (22H, m, CH2), 2.14−
2.26 (2H, m, CH2), 2.32−2.46 (2H, m, PCH), 3.10 (6H, s, py-CH3),
3.07−3.14 (2H, m, NCH), 7.23−7.29 (2H, m, py-H), 7.70−7.93 (5H,
m, 4Ar-H, Py-H). 13C{1H} NMR (100 MHz, CD2Cl2): δ 159.29,
147.07 (d, J = 8.8 Hz), 140.02, 135.76, 133.59 (d, J = 5.2 Hz), 132.54
(d, J = 2.0 Hz), 128.43 (d, J = 5.2 Hz), 127.73 (d, J = 30.6 Hz), 123.72
(d, J = 3.0 Hz), 60.72, 36.39 (d, J = 25.2 Hz), 32.82, 30.42 (d, J =
3.6 Hz), 29.44, 27.64 (d, J = 33.8 Hz), 27.63 (d, J = 8.4 Hz), 27.03,
26.83 (d, J = 1.2 Hz), 26.66, 25.79, −4.61 (d, J = 2.4 Hz). 31P{1H}
NMR (162 MHz, CD2Cl2): δ 32.73 ppm. Anal. Calcd for
C38H60F6N2O2PPdSSb·CH2Cl2: C, 43.90; H, 5.86; N, 2.63. Found:
C, 43.97; H, 6.09; N, 2.75.
Complex 4a.
Complex 4d.
Complex 3a (0.20 g, 0.30 mmol) was dissolved in 30 mL of CH2Cl2.
To the light yellow solution was added lutidine (35 μL, 0.30 mmol),
and the solution was stirred for 30 min. Then 0.30 mmol of silver
hexafluoroantimonate (AgSbF6; 0.1 g) was added to the reaction
mixture. The mixture was stirred vigorously at room temperature for
3 h. The gray solid was removed by filtration through Celite, and the
filtrate was evaporated and dried under vacuum. The residue was
further purified by recrystallization from a dichloromethane/hexane
mixture. Crystals suitable for X-ray diffraction were obtained in this
mixed solution at room temperature. Pure 4a was obtained as colorless
The same procedure as described for the synthesis of 4a was used. The
complex 3d (0.20 g, 0.32 mmol), lutidine (37 μL, 0.32 mmol), and
AgSbF6 (0.11 g, 0.32 mmol) were used to give 4d (0.22 g, 76%) as a
1
light yellow solid. H NMR (400 MHz, CD2Cl2): δ 0.72 (3H, d, J =
2.0 Hz, Pd-CH3), 1.00−1.22 (6H, m, CH2), 1.26−1.38 [12H, m,
CH(CH3)2], 1.52−1.77 (14H, m, CH2), 2.63−2.74 (2H, m, PCH),
3.05−3.17 (2H, m, NCH), 3.11 (6H, s, py-CH3), 7.27 (2H, d, J = 7.8
Hz, py-H), 7.72−7.95 (5H, m, 4Ar-H, py-H).13C{1H} NMR
(100 MHz, CD2Cl2): δ 158.85, 146.55 (d, J = 8.6 Hz), 139.64,
135.11, 133.25 (d, J = 5.2 Hz), 132.29 (d, J = 2.0 Hz), 129.12 (d, J =
5.6 Hz), 127.25 (d, J = 31.2 Hz), 123.32 (d, J = 3.0 Hz), 60.30, 32.37,
26.57, 26.55 (d, J = 25.8 Hz), 26.17, 25.36, 19.38 (d, J = 4.6 Hz), 18.43,
−5.57 (d, J = 2.8 Hz). 31P{1H} NMR (162 MHz, CD2Cl2): δ 39.99 ppm.
1
crystals in a yield of 79% (0.23 g). H NMR (400 MHz, CD2Cl2): δ
0.60 (3H, d, J = 2.8 Hz, Pd-CH3), 0.82−1.15 (6H, m, CH2), 1.45−1.72
(14H, m, CH2), 3.05−3.16 (2H, m, NCH), 3.11 (6H, s, py-CH3),
7.24−7.29 (1H, m, py-H), 7.29 (2H, d, J = 7.8 Hz, py-H), 7.50−7.70
(11H, m, Ar-H), 7.76 (2H, t, J = 7.8 Hz Ar-H), 7.87−7.93 (1H, m, Ar-
H). 13C{1H} NMR (100 MHz, CD2Cl2): δ 159.22, 146.18 (d, J = 11.8
Hz), 140.27, 137.45, 134.79 (d, J = 12.6 Hz), 133.99 (d, J = 6.2 Hz),
3743
dx.doi.org/10.1021/om5004094 | Organometallics 2014, 33, 3738−3745

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Article
Anal. Calcd for C32H52F6N2O2PPdSSb: C, 42.61; H, 5.81; N, 3.11.
Found: C, 42.27; H, 5.98; N, 2.95.
Complex 4e.
AUTHOR INFORMATION
Corresponding Authors
*E-mail for C.C.: changle@ustc.edu.cn.
*E-mail for Z.H.: huangzh@sioc.ac.cn.
■
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
The same procedure as described for the synthesis of 4a was used. The
complex 3e (0.20 g, 0.38 mmol), lutidine (44 μL, 0.38 mmol), and
AgSbF6 (0.13 g, 0.38 mmol) were used to give 4e (0.21 g, 67%) as a
white solid. 1H NMR (400 MHz, CD2Cl2): δ 0.60 (3H, d, J = 3.4 Hz,
Pd-CH3), 2.73 [6H, s, N(CH3)2], 3.13 [6H, s, py(CH3)2], 7.29−7.35
(3H, m, py-2H, Ar-H), 7.52−7.61 (10H, m, Ar-H), 7.71−7.85 (4H, m,
py-H, Ar-3H). 13C{1H} NMR (100 MHz, CDCl3): δ 159.17, 142.15
(d, J = 12.6 Hz), 140.34, 137.91 (d, J = 1.8 Hz), 134.80 (d, J = 12.6
Hz), 134.69, 133.24 (d, J = 1.8 Hz), 132.91 (d, J = 2.6 Hz), 131.12,
130.71, 130.20 (d, J = 11.4 Hz), 129.82 (d, J = 6.6 Hz), 129.18,
127.63, 124.14 (d, J = 2.2 Hz), 38.49, 27.17, 1.74 (d, J = 2.2 Hz).
31P{1H} NMR (162 M HZ CDCl3): δ 27.63 ppm. Anal. Calcd for
C22H36F6N2O2PPdSSb: C, 40.33; H, 3.87; N, 3.36. Found: C, 40.00;
H, 3.61; N, 3.61.
■
This work was supported by the National Natural Sciences Founda-
tion of China (Nos. 21272255, 21121062, 21374108), the
Science and Technology Commission of Shanghai Municipality
(Nos. 13QA1404200, 13JC1406900), and Anhui Provincial
Natural Science Foundation (No. 1408085QB28).
REFERENCES
■
(1) For recent reviews, see: (a) Carrow, B. P.; Nozaki, K.
Macromolecules 2014, 47, 2541. (b) Nakamura, A.; Anselment, T. M.
J.; Claverie, J.; Goodall, B.; Jordan, R. F.; Mecking, S.; Rieger, B.; Sen,
A.; van Leeuwen, P. W. N. M.; Nozaki, K. Acc. Chem. Res. 2013, 46,
1438. (c) Makio, H.; Terao, H.; Iwashita, A.; Fujita, T. Chem. Rev.
2011, 111, 2363. (d) Delferro, M.; Marks, T. J. Chem. Rev. 2011, 111,
2450. (e) Nakamura, A.; Ito, S.; Nozaki, K. Chem. Rev. 2009, 109,
5215. (f) Chen, E. Y. X. Chem. Rev. 2009, 109, 5157. (g) Gibson, V.
C.; Spitzmesser, S. K. Chem. Rev. 2002, 103, 283. (h) Mecking, S.
Coord. Chem. Rev. 2000, 203, 325. (i) Ittel, S. D.; Johnson, L. K.;
Brookhart, M. Chem. Rev. 2000, 100, 1169. (j) Camacho, D. H.; Guan,
Z. Chem. Commun. 2010, 46, 7879.
Complex 4f.
The same procedure as described for the synthesis of 4a was used. 3f
(0.20 g, 0.41 mmol), lutidine (48 μL, 0.41 mmol), and AgSbF6 (0.14 g,
0.41 mmol) were used to give 4f (0.20 g, 65%) as a light yellow solid.
1H NMR (400 MHz, CD2Cl2): δ 0.71 (3H, d, J = 2.4, Pd-CH3), 1.28
(2) (a) Johnson, L. K.; Killian, C. M.; Brookhart, M. J. Am. Chem. Soc.
1995, 117, 6414. (b) Guan, Z.; Cotts, P. M.; McCord, E. F.; McLain,
S. J. Science 1999, 283, 2059. (c) Popeney, C. S.; Levins, C. M.; Guan,
Z. Organometallics 2011, 30, 2432. (d) Popeney, C. S.; Rheingold, A.
L.; Guan, Z. Organometallics 2009, 28, 4452. (e) Leung, D. H.; Ziller, J.
W.; Guan, Z. J. Am. Chem. Soc. 2008, 130, 7538. (f) Liu, H.; Zhao, W.
Z.; Hao, X.; Redshaw, C.; Huang, W.; Sun, W. H. Organometallics
2011, 30, 2418. (g) Liu, H.; Zhao, W. Z.; Yu, J. G.; Yang, W. H.; Hao,
X.; Redshaw, C.; Chen, L. Q.; Sun, W. H. Catal. Sci. Technol. 2012, 2,
415. (h) Wang, K.; Shen, M.; Sun, W. H. Dalton Trans. 2009, 4085.
(i) Wegner, M. M.; Ott, A. K.; Rieger, B. Macromolecules 2010, 43,
3624. (j) Liu, F. S.; Hu, H. B.; Xu, Y.; Guo, L. H.; Zai, S. B.; Song, K.
M.; Gao, H. Y.; Zhang, L.; Zhu, F. M.; Wu, Q. Macromolecules 2009,
42, 7789. (k) Song, C. L.; Tang, L. M.; Li, Y. G.; Li, X. F.; Li, Y. S. J.
Polym. Sci., Part A: Polym. Chem. 2006, 44, 1964. (l) Bahuleyan, B. K.;
Son, G. W.; Park, D. W.; Ha, C. S.; Kim, I. J. Polym. Sci., Part A: Polym.
Chem. 2008, 46, 1066. (m) Chen, C.; Luo, S.; Jordan, R. F. J. Am.
Chem. Soc. 2010, 132, 5273. (n) Chen, C.; Luo, S.; Jordan, R. F. J. Am.
Chem. Soc. 2008, 130, 12892. (o) Rose, G. M.; Coates, G. W. J. Am.
Chem. Soc. 2006, 128, 4186. (p) Rose, G. M.; Coates, G. W.
Macromolecules 2008, 41, 9548.
(3) (a) Younkin, T. R.; Connor, E. F.; Henderson, J. I.; Friedrich, S.
K.; Grubbs, R. H.; Bansleben, D. A. Science 2000, 287, 460. (b) Wang,
C.; Friedrich, S.; Younkin, T. R.; Li, R. T.; Grubbs, R. H.; Bansleben,
D. A.; Day, M. W. Organometallics 1998, 17, 3149. (c) Song, D. P.;
Wang, Y. X.; Mu, H. L.; Li, B. X.; Li, Y. S. Organometallics 2011, 30,
925. (d) Delferro, M.; McInnis, J. P.; Marks, T. J. Organometallics
2010, 29, 5040. (e) Weberski, M. P.; Chen, C.; Delferro, M.;
Zuccaccia, C.; Macchioni, A.; Marks, T. J. Organometallics 2012, 31,
3773. (f) Marks, T. J. Chem. Eur. J. 2012, 18, 10715. (g) Hu, T.; Li, Y.
G.; Liu, J. Y.; Li, Y. S. Organometallics 2007, 26, 2609. (h) Mu, H. L.;
Ye, W. P.; Song, D. P.; Li, Y. S. Organometallics 2010, 29, 6282.
(i) Song, D. P.; Ye, W. P.; Wang, Y. X.; Liu, J. Y.; Li, Y. S.
Organometallics 2009, 28, 5697. (j) Song, D. P.; Wu, J. Q.; Ye, W. P.;
Mu, H. L.; Li, Y. S. Organometallics 2010, 29, 2306. (k) Song, D. P.;
Wang, Y. X.; Mu, H. L.; Li, B. X.; Li, Y. S. Organometallics 2011, 30,
[3H, d, J = 7.0, CH(CH3)2], 1.31 [3H, d, J = 2.6, CH(CH3)2], 1.33
[3H, d, J = 2.6, CH(CH3)2], 1.37 [3H, d, J = 7.0, CH(CH3)2], 2.52−
2.74 (2H, m, CHMe2), 3.00 [6H, s, N(CH3)2], 3.11 (6H, s, py-CH3),
7.28 (2H, d, J = 7.8, py-H), 7.54−7.59 (1H, m, Ar-H), 7.75 (1H, t, J =
7.8, py-H), 7.78−7.91 (3H, m, Ar-H). 13C{1H} NMR (100 MHz,
CDCl3): δ 159.39, 145.43 (d, J = 9.2 Hz), 140.03, 135.90, 133.90
(d, J = 5.2 Hz), 133.34 (d, J = 2.0 Hz), 127.36 (d, J = 5.0 Hz), 127.64,
126.63, 124.03 (d, J = 3.0 Hz), 111.43, 39.06, 26.73 (d, J = 26.4 Hz),
26.69, 19.64 (d, J = 4.6 Hz), 18.76, −4.62 (d, J = 3.0 Hz). 31P{1H}
NMR (162 MHz, CDCl3): δ 39.06 ppm. Anal. Calcd for
C22H36F6N2O2PPdSSb: C, 34.51; H, 4.74; N, 3.66. Found: C, 34.26;
H, 4.88; N, 3.74.
General Procedure for Ethylene Oligomerization with
Complexes 4a−f. Ethylene oligomerization reactions were per-
formed in a 300 mL stainless steel autoclave with a magnetic stirrer. In
the glovebox, the catalyst was weighed and dissolved in 5 mL of
CH2Cl2. The autoclave was heated under vacuum for 1 h to 100 °C
and then cooled to the required reaction temperature under an
ethylene atmosphere and charged with 100 mL of CH2Cl2. The
solution was stirred for about 30 min. Then the catalyst in CH2Cl2 was
added. The reactor was then pressurized with ethylene, and the
ethylene pressure was kept constant during the oligomerization
reaction. After 30 min, the autoclave was cooled quickly with liquid
nitrogen/ethanol, and then the ethylene pressure was released slowly.
Quantitative GC analysis of the product was performed immediately
with n-heptane as an internal standard.
ASSOCIATED CONTENT
■
S
* Supporting Information
Text, tables, figures, and CIF files giving crystallographic data
for complex 4a, GC methods and GC spectra, and IR spectra of
ligand 2f complexes 4a,f in the solid state and in solution. This
material is available free of charge via the Internet at http://
pubs.acs.org.
925. (l) Gottker-Schnetmann, I.; Wehrmann, P.; Rohr, C.; Mecking, S.
̈
̈
Organometallics 2007, 26, 2348. (m) Bastero, A.; Gottker-Schnetmann,
̈
I.; Rohr, C.; Mecking, S. Adv. Synth. Catal. 2007, 349, 2307.
(n) Berkefeld, A.; Mecking, S. J. Am. Chem. Soc. 2009, 131, 1565.
̈
3744
dx.doi.org/10.1021/om5004094 | Organometallics 2014, 33, 3738−3745

Organometallics
Article
(o) Osichow, A.; Gottker-Schnetmann, I.; Mecking, S. Organometallics
̈
2013, 32, 5239.
(4) Keim, W.; Kowaldt, F. H.; Goddard, R.; Kruger, C. Angew. Chem.,
̈
Int. Ed. Engl. 1978, 17, 466.
(5) (a) Atkinson, R. C. J.; Gibson, V. C.; Long, N. J.; White, A. J. P.
Dalton Trans. 2010, 39, 7540. (b) Kermaqoret, A.; Braunstein, P.
Dalton Trans. 2008, 822. (c) Mateus, N.; Routaboul, L.; Daran, J. C.;
Manoury, E. J. Organomet. Chem. 2006, 691, 2297. (d) Malinoski, J.
M.; Brookhart, M. Organometallics 2003, 22, 5324.
(6) (a) Drent, E.; van Dijk, R.; van Ginkel, R.; van Oort, B.; Pugh, R.
I. Chem. Commun. 2002, 744. (b) Drent, E.; van Dijk, R.; van Ginkel,
R.; van Oort, B.; Pugh, R. I. Chem. Commun. 2002, 964. (c) Kochi, T.;
Yoshimura, K.; Nozaki, K. Dalton Trans. 2006, 25. (d) Kochi, T.;
Noda, S.; Yoshimura, K.; Nozaki, K. J. Am. Chem. Soc. 2007, 129, 8948.
(e) Weng, W.; Shen, Z. L.; Jordan, R. F. J. Am. Chem. Soc. 2007, 129,
15450. (f) Vela, J.; Lief, G. R.; Shen, Z. L.; Jordan, R. F.
Organometallics 2009, 28, 6131. (g) Skupov, K. M.; Piche, L.;
Claverie, J. P. Macromolecules 2008, 41, 2309. (h) Ito, S.; Munakata,
K.; Nakamura, A.; Nozaki, K. J. Am. Chem. Soc. 2009, 131, 14606.
(i) Noda, S.; Nakamura, A.; Kochi, T.; Chung, L. W.; Morokuma, K.;
Nozaki, K. J. Am. Chem. Soc. 2009, 131, 14088. (j) Guironnet, D.;
Roesle, P.; Runzi, T.; Gottker, S. I.; Mecking, S. J. Am. Chem. Soc.
̈
̈
2009, 131, 422. (k) Neuwald, B.; Caporaso, L.; Cavallo, L.; Mecking,
S. J. Am. Chem. Soc. 2013, 135, 1026.
(7) Nagai, Y.; Kochi, T.; Nozaki, K. Organometallics 2009, 28, 6131.
(8) Zhou, X. Y.; Jordan, R. F. Organometallics 2011, 30, 4632.
(9) (a) Gott, A. L.; Piers, W. E.; Dutton, J. L.; Mcdonald, R.; Parvez,
M. Organometallics 2011, 30, 4236. (b) Kim, Y.; Jordan, R. F.
Organometallics 2011, 30, 4250.
(10) (a) Bennett, J. L.; Brookhart, M.; Johnson, L. K. PCT Int. Appl.
WO 9830610, 1998;. (b) Nozaki, K.; kawauchi, T.; Ida, H. Jpn. Kokai
Tokkyo Koho, JP 2007332086, 2007.
(11) Liu, W. J.; Malinoski, J. M.; Brookhart, M. Organometallics 2002,
21, 2836.
(12) Carrow, B. P.; Nozaki, K. J. Am. Chem. Soc. 2012, 134, 8802.
(13) Chapman, C. J.; Frost, C. G.; Mahon, M. F. Dalton Trans. 2006,
2251.
(14) Burns, C. T.; Jordan, R. F. Organometallics 2007, 26, 6726.
(15) Cai, Z. G.; Shen, Z. L.; Zhou, X. Y.; Jordan, R. F. ACS Catal.
2012, 2, 1187.
(16) (a) Gutsulyak, D. G.; Gott, A. L.; Piers, W. E.; Parvez, M.
Organometallics 2013, 32, 3363. (b) Hasanayn, F.; Achord, P.;
Braunstein, P.; Magnier, H. J.; Krogh-Jespersen, K.; Goldman, A. S.
Organometallics 2012, 31, 4680.
3745
dx.doi.org/10.1021/om5004094 | Organometallics 2014, 33, 3738−3745