A Versatile Ligand Platform for Palladium- and Nickel-Catalyzed Ethylene Copolymerization with Polar Monomers

Article abstract of DOI:10.1002/anie.201711753

The ability to carry out transition-metal-catalyzed copolymerizations of olefins with polar monomers is a great challenge in the field of olefin polymerization. Palladium has been the dominant player in this field, while its low-cost nickel counterpart has only achieved very limited success. We report the synthesis and evaluation of a highly versatile platform based on diphosphazane monoxide ligands. Both palladium and nickel catalysts bearing these ligands mediate the copolymerization of ethylene with a number of fundamental polar monomers.

Full text of DOI:10.1002/anie.201711753

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Accepted Article
Title: A Versatile Ligand Platform for Palladium- and Nickel-catalyzed
Ethylene Copolymerizations with Polar Monomers
Authors: Min Chen and Changle Chen
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A Versatile Ligand Platform for Palladium- and Nickel-catalyzed
Ethylene Copolymerizations with Polar Monomers
Min Chen, Changle Chen*
Abstract: The ability to carry out transition-metal catalyzed
copolymerizations of olefins with polar monomers is a grand
challenge in the field of olefin polymerization. Palladium has
been the dominant player in this field, while its low-cost nickel
counterpart has only achieved very limited success. In this
contribution, we report the synthesis and evaluation of a highly
versatile platform based on diphosphazane monoxide ligands.
Both palladium and nickel catalysts bearing these ligands
mediate the copolymerizations of ethylene with some
fundamental polar monomers.
Scheme 1. Selected examples of previously reported palladium and nickel
catalysts for ethylene and polar monomer copolymerization (M = Pd, Ni).
Currently, polyolefins represent almost half of the 300 million
tons of plastics produced worldwide.[1] The incorporation of polar
The electronic asymmetry of the phosphine-sulfonate ligand
framework, bearing both strong σ-donating phosphine and weak
σ-donating sulfonate groups, is believed to be critical for
facilitating a variety of copolymerizations.[15] We envisage that
the combination of “ligand rigidity strategy”, induced by short-bite
ligands[23] and bulky substituents, and the above-mentioned
"electronic-asymmetry strategy" may provide high- performance
catalysts.
functional groups would greatly improve the properties of
polyolefins that are limited by their non-polar nature.[2] As the
most economical and direct synthetic approach, the transition-
metal-mediated
ethylene/polar-monomer
copolymerization
remains a grand challenge in this field.[3] Palladium has been the
dominant metal used to address this polar-monomer problem.[4]
In contrast, the use of Earth-abundant and low-cost nickel metal
has proven to be very difficult because of its intrinsically high
oxophilicity.
Brookhart’s α-diimine palladium catalyst (Scheme 1, I)
represents
a
milestone discovery as it facilitates the
copolymerization of ethylene with fundamental polar monomers
(with polar groups directly attached to the double bond) such as
acrylates,[5,6] vinylalkoxysilanes,[7] and some specific polar
monomers (with polar groups not directly attached to the double
bond).[8] Meanwhile, α-diimine nickel catalysts can mediate
ethylene
copolymerizations
with
methyl
acrylate,[9a]
vinylalkoxysilanes,[9b] and some specific polar monomers.[10] The
Grubbs-type salicylaldimine nickel catalysts II[11] and the
sterically bulky SHOP (Shell Higher Olefin Process) nickel
catalysts III[12] copolymerize ethylene with a few specific polar
monomers, while their palladium counterparts only oligomerize
ethylene.[13,14] Phosphine-sulfonate-based palladium catalysts IV
have been demonstrated to copolymerize ethylene with a variety
of different fundamental polar monomers,[15] while their nickel
counterparts only facilitate copolymerizations with some specific
polar monomers.[16] Similar observations have been reported for
some related ligand systems, such as bisphosphine monoxides
V,[17,18] phosphine phosphonic amides VI,[19,20] and specially
designed N-heterocyclic carbenes VII.[21,22] In these systems, the
copolymerization parameters such as activities and copolymer
molecular weights are far from those required for practical
applications. Therefore, it is highly desired to develop new
catalysts as well as new ligand design strategies.
Scheme 2. Modular syntheses of the PNPO ligands and the corresponding
palladium and nickel complexes.
The diphosphazane monoxide (PNPO) ligands L1–L5 were
easily prepared in high yields in a straightforward and modular
fashion (Scheme 2). As such, the electronic and steric properties
of the three building blocks can easily be adjusted, providing
significant flexibility and allowing the properties of the palladium
and nickel catalysts to be tuned. These ligands can also be
prepared by the mono-oxidation of the extensively studied
diphosphazane ligands,[23,24] making them more versatile and
attractive from a synthetic perspective. In addition to this
structural feature, the ligand framework also leads to five-
membered metal chelates that are smaller than phosphine-
sulfonates and related systems (IV, V, VI, and VII). This imparts
additional rigidity into the catalyst structure, which may be
beneficial for enhancing its catalytic properties.[15b,15c]
Subsequently, the desired palladium (Pd1–Pd5) and nickel
(Ni1–Ni5) complexes were prepared in high yields through the
reactions of the ligands with (COD)PdMeCl (COD = 1, 5-
cyclooctadiene) and [Ni(allyl)Cl]2 as metal precursors.
[*]
M. Chen, Prof. C. Chen, CAS Key Laboratory of Soft Matter
Chemistry, iChEM (Collaborative Innovation Center of Chemistry for
Energy Materials), Department of Polymer Science and
Engineering, University of Science and Technology of China, Hefei
230026 (China)
E-mail: changle@ustc.edu.cn
Supporting information for this article is given via a link at the end of
the document.
The molecular structures of Pd3, Pd5, Ni3 and Ni4 were
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Table 1: Pd catalyzed ethylene-polar monomer copolymerizations.[a]
determined by X-ray diffraction (Figure 1). The geometry at the
Pd or Ni center is square planar in each complex. The
substituents on the phosphine moiety directly affect the steric
environment around the metal center. The phosphine moiety in
Yield
Act.
Comono
mer
XM
Tm
[d]
Ent.
Cat.
Mn
PDI[d]
(%)[c]
(°C)[e]
(g)[b] (103)[b]
Pd1
Pd2
Pd3
Pd4
Pd5
Pd1
Pd2
Pd1
Pd2
Pd1
1
2
MA
MA
2.0
1.3
0.1
16.7
10.8
0.8
6.8
1.7
4.4
6100
7400
5700
2.5
2.6
2.5
101
121
104
3
MA
4
MA
0.4
1.5
3.3
2.1
1.5
3000
5900
2.4
2.5
115
120
12.5
5
MA
6
AA
0.9
0.2
0.7
0.4
0.2
7.5
1.7
5.8
3.3
1.7
6.3
2.0
4.4
1.5
0.2
2800
5100
2800
9200
5700
2.9
2.7
3.0
2.2
1.9
113
127
124
128
124
7
AA
8
BVE
BVE
MMA
9
10[f]
[a] Polymerization conditions: total volume of solvent and polar monomer(1
M/L) = 20 mL, catalyst = 20 μmol, 1.2 eq. NaBAF, ethylene = 8 atm, 80 °C,
time = 6 h. [b]The yields and activities are average of at least two runs. Activity
is in unit of 103 g·mol-1·h -1. [c] Determined by 1H NMR in C2D2Cl4 at 120 °C. [d]
Determined by GPC in trichlorobenzene at 150 °C. [e] Determined by DSC. [f]
ethylene = 1 atm, 5 mL MMA was used without solvent.
chain-transfer pathway.[28,29] Compared to Pd2, Pd4 bearing the
electron-donating MeO substituent, provided polyethylene of
higher molecular weight, while Pd5, bearing the electron-
withdrawing CF3 substituent, provided a lower molecular weight.
The nickel complexes are highly active single-component
catalysts for ethylene polymerization at 80 °C (Table S1, entries
6–10). Ni1 exhibited the lowest activity and gave the lowest
polyethylene molecular weight. In comparison with the palladium
analogues, similar polymer molecular-weight trends were
observed using Ni2–Ni5 with ligands of different electronic
demand. At 25 °C, the activities of Ni1, Ni2, Ni3, and Ni5 were
very low (Table S1, entries 11–13 and 15). In contrast, Ni4
remained highly active at 25 °C, providing polyethylene with a
very high molecular weight (Mn = 189,000) and high melting
point (136 °C) (Table S1, entry 14).
The palladium complexes Pd1–Pd5 mediated ethylene (E)
copolymerization with methyl acrylate (MA) (Table 1, entries 1–
5), with moderate activities, good levels of MA incorporation,
moderate copolymer molecular weights, and high copolymer
melting temperatures. Ethylene copolymerizations with acrylic
acid (AA) and butyl vinyl ether (BVE) were also facilitated (Table
1, entries 6–9). The extensively studied α-diimine palladium,[30]
salicylaldimine nickel,[31] and phosphine-sulfonate palladium[32]
catalysts are incapable of incorporating methyl methacrylate
(MMA) comonomer during the polymerization of ethylene. In
contrast, MMA was observed to be incorporated to give enolate-
terminated polyethylenes in this system (Figure S4).[33]
Figure 1. Molecular structures of Pd3, Pd5, Ni3 and Ni4.[27] Hydrogen atoms
are omitted for clarity.
Pd3 exhibits P-chirality with the phenyl substituent on P1
directed externally to its structure, while the phenyl substituent
on P1 is directed internally in Pd5. Only one set of NMR
resonances was observed for each palladium complex. For each
nickel complex Ni2–Ni5, two sets of NMR resonances were
observed in solution, which collapsed to a single set of broad
resonances at 80 °C (Figure S1). This behavior has its origins in
the rotationally hindered and therefore stereogenic biaryl
substituent; consequently two conformational isomers (stereo-
labile atropisomers) exist.[25] Only one set of NMR resonances
was observed for a variety of phosphine-biaryl substituents in
the phosphine-sulfonate nickel system,[26] which supports our
hypothesis involving the improvement of ligand rigidity through
the use of short-bite ligands.
These palladium complexes are highly active for ethylene
polymerization when activated with 1.2 equiv. of sodium tetrakis
(3, 5-bis(trifluoromethyl)phenyl)borate (NaBAF) (Table S1,
entries 1–5). Pd1 was observed to be the most active catalyst,
but generated polyethylene with a relatively low molecular
weight. Pd3 bearing the electron-donating iso-propyl substituent
is the least active catalyst but gives polyethylene with the
highest molecular weight. Temperature studies using Pd2 reveal
that activity increases with increasing temperature, while the
polyethylene molecular weight decreases (Table S2); time-
dependence studies show that Pd2 remains active for 2 h at 100
°C (Figure S2). When the ethylene pressure was increased from
1 to 2, 5, and 8 atm, the activity of the catalyst and the molecular
weight of the polyethylene produced both increased almost
linearly with pressure (Figure S3). This indicates that chain
transfer to the metal (β-hydride elimination) is the dominant
Generally, nickel is more oxophilic than palladium. As such, it
is significantly more challenging for nickel catalysts to exhibit
good behavior in ethylene/polar-monomer copolymerizations.
Remarkably, nickel catalysts Ni2–Ni5 performed similarly as
their palladium counterparts in terms of activity, comonomer
incorporation, copolymer molecular weight, and melting
temperature in E-MA copolymerizations (Table 2, entries 1–5).
The use of the sterically bulkier butyl acrylate (BA) comonomer
led to increased comonomer incorporation at the expense of
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10.1002/anie.201711753
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system, no insertion/reaction was observed using [Pd1]+ due to
the weakly coordinating capability of the electron-deficient and
sterically bulky MMA monomer. Using the in-situ generated
cationic species, exclusive 2, 1-insertion of MMA was observed
(Scheme 3d, Figures S14–17), suggesting that the electronic
effect prevails in this system, which may also be responsible for
the successful incorporation of MMA. Most interestingly, the
cationic palladium species can undergo multiple MA or BVE
insertions (Scheme 3e, Figures S19, 20), making it a very rare
example of a catalyst with such capabilities.[35]
Table 2: Ni catalyzed ethylene-polar monomer copolymerizations.[a]
Comono Yield
mer
Act.
XM
Tm
[d]
Ent. Cat.
Mn
PDI[d]
(g)[b]
(103)[b]
(%)[c]
(°C)[e]
Ni1
Ni2
Ni3
Ni4
Ni5
Ni2
Ni3
Ni4
Ni5
Ni4
Ni4
Ni4
Ni4
6.5
2.1
2.6
2.4
2.5
2.4
4.7
4.5
3.2
4.0
1.1
2.0
0.9
1
2
MA
MA
0.1
0.7
0.3
1.1
0.4
0.4
0.1
0.4
0.3
0.2
0.1
0.2
0.1
0.8
5.8
2.5
9.2
3.3
3.3
0.8
3.3
2.5
1.7
0.8
1.7
0.8
3000
9900
8200
6400
7600
6200
6300
5000
5300
6300
2.3
2.2
2.0
2.3
2.1
2.7
2.6
2.5
2.3
2.6
113
123
120
118
124
117
117
118
121
115
124
125
126
3
MA
4
MA
5
MA
6
BA
7
BA
8
BA
9
BA
10
11
12
13[f]
MEA
DFBA
BVE
MA
17900 2.1
8000 2.0
20700 2.5
[a] Polymerization conditions: total volume of solvent and polar monomer (1
M/L) = 20 mL, catalyst = 20 μmol, ethylene = 8 atm, 80 °C, time = 6 h. [b] The
yields and activities are average of at least two runs. Activity is in unit of 103
g·mol-1·h -1. [c] Determined by 1H NMR in C2D2Cl4 at 120 °C. [d] Determined by
GPC in trichlorobenzene at 150 °C. [e] Determined by DSC. [f] T = 25 °C.
activity (Table 2, entries 6–9). High comonomer incorporation
and high copolymer molecular weight were also observed using
2-methoxyethyl acrylate (MEA) (Table 2, entry 10). This result
highlights the excellent functional-group tolerance of this nickel
system, considering that MEA insertion affords stable metal
chelates involving multiple oxygen atoms. The electron-deficient
1,1-dihydroheptafluorobutyl acrylate (DFBA) comonomer was
also copolymerized with ethylene (Table 2, entry 11), suggesting
that the cationic nickel center is highly electrophilic. The very
high molecular weight for this case is probably due to reduced
acrylate poisoning resulting from the use of the electron-
withdrawing fluorine-containing substituent. Copolymerization
was also achieved using BVE (Table 2, entry 12). The activity
and comonomer incorporation were reduced at room
temperature during the Ni4-catalyzed E-MA copolymerization
(Table 2, entry 13); however, a greatly enhanced copolymer
molecular weight was observed.
Scheme 3. (a) Generation of cationic species and their decomposition
pathways. Kinetic studies using (b) MA, (c) EVE, and (d) MMA. (e) Multiple
insertions of MA and BVE into the palladium species.
To conclude, both palladium and nickel catalysts constructed
on the PNPO ligand platform mediate ethylene polymerization
and copolymerizations with fundamental polar monomers. Most
interestingly, the nickel catalysts exhibit comparable behavior in
these copolymerization reactions to their palladium analogues.
The unique properties of this system are believed to have its
origins in the short-bite ligand platform, which sufficiently
increases ligand rigidity. In addition, the electronic-asymmetry
features of the ligands that result from the combinations of
strong σ-donating phosphine moieties and weak σ-donating
phosphine oxide moieties, contribute to their unique properties.
We are currently exploring other short-bite ligands possessing
electronic asymmetry with the aim of discovering further high
performance catalysts as well general ligand-design principles.
During mechanistic studies,
a
single-component [Pd1]+
cationic species was generated and isolated from the reaction of
Pd1 with 1 equiv. of NaBAF (Scheme 3a). [Pd1]+ was not stable
and undergoes slow reductive elimination at room temperature
over several days to give dimeric [PdI-PdI] (Scheme 3a, Figure
S5). This dimeric species was also observed during ethylene
polymerization or copolymerization, suggesting that a common
decomposition pathway exists for this class of catalyst (Figure
S6).
Acknowledgement
This work was supported by National Natural Science
Foundation of China (NSFC, 21704094, 51522306 and
21690071).
Kinetic studies under pseudo-first-order conditions (~30 equiv.
of monomer) showed exclusive 2, 1-insertion for MA (Scheme
3b, Figures S7–10) and 1, 2-insertion for ethyl vinyl ether (EVE,
Scheme 3c, Figures S11–13). This is consistent with the
regioselectivity observed in the phosphine-sulfonate palladium
system.[34] From an electronic perspective, 2, 1-insertion is
preferred for the MMA monomer, while 1, 2-insertion is preferred
sterically. In the phosphine-sulfonate palladium system, a ~3:2
ratio of 1, 2- vs. 2, 1-insertion was observed. In the current
Conflict of interest
The authors declare no conflict of interest.
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10.1002/anie.201711753
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Keywords: Olefin polymerization • copolymerization • palladium
and nickel catalysis • polar monomer
Kobayashi, S. Kitade, K. Sakata, T. Tayano, K. Nozaki, Angew. Chem. Int.
Ed. 2016, 55, 7505-7509.
[16] a) S. I Ito, Y. Ota, K. Nozaki, Dalton Trans. 2012, 41, 13807-13809; b) M.
Chen, C. L. Chen, ACS Catal. 2017, 7, 1308-1312.
[1] M. Sturzel, S. Mihan, R. Mulhaupt, Chem Rev. 2016, 116, 1398-1433.
[2] a) T. C. Chung, Functionalization of Polyolefins; Academic Press: San
Diego, CA, 2002; b) J. Y. Dong, Y. Hu, Coord. Chem. Rev. 2006, 250, 47-
65.
[17] B. P. Carrow, K. Nozaki, J. Am. Chem. Soc. 2012, 134, 8802-8805.
[18] Oligomerization of ethylene has been reported using this type of nickel
complexes. I. Brassat, W. Keim, S. Killat, M. Mothrath, P. Mastrorilli, C. F.
Nobile, G. P. Suranna, J. Mol. Catal. A: Chem. 2000, 157, 41-58.
[19] X. L. Sui, S. Y. Dai, C. L. Chen, ACS Catal. 2015, 5, 5932-5937.
[20] This type of nickel complexes can copolymerize ethylene with some
special polar monomers such as methyl 10-undecenoate.
[21] R. Nakano, K. Nozaki, J. Am. Chem. Soc. 2015, 137, 10934-10937.
[22] W. Tao, R. Nakano, S. Ito, K. Nozaki, Angew. Chem. Int. Ed. 2016, 55,
2835-2839.
[3] J. A. Gladysz, Z. T. Ball, G. Bertrand, S. A. Blum, V. M. Dong, R. Dorta, F.
E. Hahn, M. G. Humphrey, W. D. Jones, J. Klosin, I. Manners, T. J. Marks,
J. M. Mayer, B. Rieger, J. C. Ritter, A. P. Sattelberger, J. M. Schomaker, V.
W.-W. Yam, Organometallics 2012, 31, 1-18.
[4] a) A. Nakamura, S. Ito, K. Nozaki, Chem. Rev. 2009, 109, 5215-5244; b) E.
Y. X. Chen, Chem. Rev. 2009, 109, 5157-5214.
[5] a) L. K. Johnson, S. Mecking, M. Brookhart, J. Am. Chem. Soc. 1996, 118,
267-268; b) S. Y. Dai, X. L. Sui, C. L. Chen, Angew. Chem, Int. Ed. 2015,
54, 9948-9953; c) S. Y. Dai, S. X. Zhou, W. Zhang, C. L. Chen,
Macromolecules 2016, 49, 8855-8862; d) X. L. Sui, C. W. Hong, W. M.
Pang, C. L. Chen, Mater. Chem. Front. 2017, 1, 967-972.
[23] C. Fliedel, A. Ghisolfi, P. Braunstein, Chem. Rev. 2016, 116, 9237-9304.
[24] R. P. Kamalesh-Babu, K. Aparna, S. S. Krishnamurthy, M. Nethaji,
Phosphorus, Sulfur, and Silicon 1995, 103, 39-53.
[25] a) Daniele. Casarini, C. Coluccini, L. Lunazzi, A. Mazzanti, J. Org. Chem.
2005, 70, 5098-5102; b) G. Bringmann, A. J. Price -Mortimer, P. A. Keller,
M. J. Gresser, J. Garner, M. Breuning, Angew. Chem. Int. Ed. 2005, 44,
5384-5427.
[6] a) S. Luo, R. F. Jordan, J. Am. Chem. Soc. 2006, 128, 12072-12073; b) C.
Chen, S. Luo, R. F. Jordan, J. Am. Chem. Soc. 2010, 132, 5273-5284.
[7] Z. Chen, W. Liu, O. Daugulis, M. Brookhart, J. Am. Chem. Soc. 2016, 138,
16120-16129.
[26] a) P. Perrotin, J. S. J. McCahill, G. Wu, S. L. Scott, Chem. Commun. 2011,
47, 6948-6950; b) B. P. Yang, S. Y. Xiong, C. L. Chen, Poly. Chem.
2017, 8, 6272-6276.
[8] a) D. H. Camacho, Z. Guan, Chem. Commun. 2010, 46, 7879-7893; b) Z.
Dong, Z. Ye, Polym. Chem. 2012, 3, 286-301; c) D. Takeuchi, Polym. J.
2012, 44, 919; d) L. H. Guo, S. Y. Dai, X. L. Sui, C. L. Chen, ACS Catal.
2016, 6, 428-441; e) S. Y. Dai, C. L. Chen, Angew. Chem. Int. Ed. 2016, 55,
13281-13285; f) M. Li, X. B. Wang, Y. Luo, C. L. Chen, Angew. Chem. Int.
Ed. 2017, 56, 11604-11609.
[27] CCDC 1580539 (Pd3), 1580537 (Pd5), 1580538 (Ni3), 1580541 (Ni4),
and 1580542 ([PdI-PdI]) contain the supplementary crystallographic data
for this paper. These data can be obtained free of charge from The
Cambridge Crystallographic Data Centre.
[9] a) L. K. Johnson, L. Wang, S. McLain, A. Bennett, K. Dobbs, E. Hauptman,
A. Ionkin, S. D. Ittel, K. Kutnisky, W. Marshall, E. McCord, C. Radzewich, A.
Rinehart, K. J. Sweetman, Y. Wang, Z. Yin, M. Brookhart, ACS Symp. Ser.
2003, 857, 131; b) Z. Chen, M. D. Leatherman, O. Daugulis, M. Brookhart,
J. Am. Chem. Soc. 2017, 139, 16013–16022.
[28] a) M. P. Weberski, C. L. Chen, M. Delferro, C. Zuccaccia, A. Macchioni, T.
J. Marks, Organometallics 2012, 31, 3773-3789; b) G. Talarico, P. H. M.
Budzelaar, Organometallics 2008, 27, 4098-4107.
[29] a) If chain transfer to the monomer were occurring, constant Mn would be
observed irrespective of ethylene pressure because the propagation/chain
transfer ratio is independent of ethylene pressure. b) L. Deng, P. Margl, T.
Ziegler, J. Am. Chem. Soc. 1997, 119, 1094-1100.
[10] a) B. K. Long, J. M. Eagan, M. Mulzer, G. W. Coates, Angew. Chem. Int.
Ed. 2016, 55, 7106-7110; b) L. Zhong, G. Li, G. Liang, H. Gao, Q. Wu,
Macromolecules 2017, 50, 2675-2682 .
[30] S. Borkar, H. Yennawar, A. Sen, Organometallics 2007, 26, 4711-4714.
[31] E. F. Connor, T. R. Younkin, J. I. Henderson, S. Hwang, R. H. Grubbs, W.
P. Roberts, J. J. J. Litzau, Polym. Sci., Part A: Polym. Chem. 2002, 40,
2842-2859.
[11] a) T. R. Younkin, E. F. Connor, J. I. Henderson, S. K. Friedrich, R. H.
Grubbs, D. A. Bansleben, Science, 2000, 287, 460-462; b) M. R. Radlauer,
A. K. Buckley, L. M. Henling, T. Agapie, J. Am. Chem. Soc. 2013, 135,
3784-3787; c) M. P. Weberski, C. L. Chen, M. Delferro, T. J. Marks, Chem.
Eur. J. 2012, 18, 10715-10732; d) A. Osichow, I. Gꢀttker-Schnetmann, S.
Mecking, Organometallics 2013, 32, 5239-5242; e) D. Takeuchi, Y. Chiba,
S. Takano, K. Osakada, Angew. Chem. Int. Ed. 2013, 52, 12536-12540.
[12] a) U. Klabunde, S. D. Itten, J. Mol. Catal. 1987, 41, 123-134; b) U.
Klabunde, W. Chester, Pa. 1987, US 4, 698, 403.
[32] T. Runzi, D. Guironnet, I. Gottker-Schnetmann, S. Mecking, J. Am. Chem.
Soc. 2010, 132, 16623-16630.
[33] a) V. C. Gibson, A. Tomov, Chem. Commun. 2001, 19, 1964-1965. An
example of in chain MMA incorporation was recently demonstrated, see b)
H. Yasuda, R. Nakano, S. Ito, K. Nozaki, J. Am. Chem. Soc. 2018,
DOI: 10.1021/jacs.7b12593.
[13] K. Nozaki, S. Kusumoto, S. Noda, T. Kochi, L. W. Chung, K. Morokuma, J.
Am. Chem. Soc. 2010, 132, 16030-10642.
[34] a) S. Luo, J. Vela, G. R. Lief, R. F. Jordan, J. Am. Chem. Soc. 2007, 129,
8946-8947; b) D. Guironnet, L. Caporaso, B. Neuwald, I. Gottker-
Schnetmann, L. Cavallo, S. Mecking, J. Am. Chem. Soc. 2010, 132,
4418-4426.
[14] a) W. Liu, J. M. Malinoski, M. Brookhart, Organometallics 2002, 21, 2836-
2838; b) J. Heinicke, M. Kohler, N. Peulecke, M. K. Kindermann, W. Keim,
M. Kockerling, Organometallics 2005, 24, 344-352.
[35] a) C. Chen, S. Luo, R. F. Jordan, J. Am. Chem. Soc. 2008, 130, 12892-
12893; b) D. Guironnet, P. Roesle, T. Runzi, I. Gottker-Schnetmann, S.
Mecking, J. Am. Chem. Soc. 2009, 131, 422-423.
[15] a) A. Nakamura, T. M. J. Anselment, J. Claverie, B. Goodall, R. F. Jordan,
S. Mecking, B. Rieger, A. Sen, P. W. N. M. Van Leeuwen, K. Nozaki, Acc.
Chem. Res. 2013, 46, 1438-1449; b) B. Neuwald, L. Caporaso, L. Cavallo,
S. Mecking, J. Am. Chem. Soc. 2013, 135, 1026-1036; c) Y. Ota, S. Ito, M.
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10.1002/anie.201711753
Angewandte Chemie International Edition
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Min Chen, Changle Chen*
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A Versatile Ligand Platform for
Palladium- and Nickel-catalyzed
Ethylene Copolymerizations with
Polar Monomers
A versatile ligand platform based on diphosphazane monoxide ligands was designed and
evaluated. Both palladium and nickel catalysts bearing these ligands mediate
copolymerizations of ethylene with some fundamental polar monomers.
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