Polymerization of 5-norbornene-2-methyl acetate catalyzed by air-stable cationic (η3-substituted allyl) palladium complexes of N-heterocyclic carbene

Jung, Il Gu; Lee, Young Tak; Choi, Soo Young; Choi, Dae Seung; Kang, Youn K.; Chung, Young Keun

doi:10.1016/j.jorganchem.2008.10.058

Cited by 34 publications

(4 citation statements)

References 65 publications

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“…It seems attractive to use Pd complexes bearing NHC ligands as (pre)catalysts for the addition polymerization of norbornene derivatives. Only a few publications ,− were devoted to the addition polymerization of functionalized norbornenes over systems containing Pd–NHC complexes, and the influence of NHC ligands on the catalytic properties of Pd complexes was not clearly established. The promising properties of (NHC)Pd catalysts for the polymerization of substituted norbornenes were also shown by carrying out the process in the presence of a large excess of water .…”

Section: Introductionmentioning

confidence: 99%

Polymerization of 5-Alkylidene-2-norbornenes with Highly Active Pd–N-Heterocyclic Carbene Complex Catalysts: Catalyst Structure–Activity Relationships

et al. 2019

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We studied the addition polymerization of readily available bifunctional norbornene derivatives, 5-alkylidene-2-norbornenes, in the presence of modified Pd complexes with N-heterocyclic carbene ligands activated by borates. The Pd−N-heterocyclic carbene complex/phosphine/borate systems selectively catalyze the addition polymerization of 5methylene-2-norbornene and 5-ethylidene-2-norbornene with the participation of the endocyclic norbornene double bond, whereas the exocyclic double bond remained intact. The catalysts exhibited extremely high activity and durability: the activity was higher than 1 × 10 8 g polymer / (mol Pd •h) and some catalysts were active at a very high monomer/Pd molar ratio of 2 × 10 7 or at a Pd complex concentration of 5 × 10 −6 mol %. The structure−catalytic activity relationships were established for Pd−N-heterocyclic carbene complexes: the Pd complexes bearing five-membered heterocyclic rings and/or less sterically hindered aryl groups at nitrogen atoms in carbene ligands exhibited the highest activity. The polymerization can be performed in an atmosphere of air and in wet solvents. The resulting polymers are amorphous and high-molecular-weight products consisting of rigid saturated main chains and reactive side groups. Thus, they can be considered as promising intermediates in the production of polymeric materials with high glass-transition temperatures and desired properties by targeted modifications.

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Section: Introductionmentioning

confidence: 99%

Polymerization of 5-Alkylidene-2-norbornenes with Highly Active Pd–N-Heterocyclic Carbene Complex Catalysts: Catalyst Structure–Activity Relationships

et al. 2019

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“…Recently, it has been demonstrated that (NHC)Pd-based systems cat-alyze vinyl-addition polymerization of various functionalized norbornenes [14][15][16][17][18][19][20][21]. For instance, these systems showed good catalytic activity in polymerization of norbornenes with hydroxy [20,22], ether [21], ester [14,15,[18][19][20]23,24], imide [14,16,17], silyl [14,19,20,24], and alkyl/alkenyl [19,20,22,24,25] functionality. At the same time, to the best of our knowledge, the polymerization of norbornene-type monomers with reactive halogen-containing groups over (NHC)Pd-catalysts has not yet been reported.…”

Section: Vinyl-addition Polymerization Of 5-bromoalkylnorbornenesmentioning

confidence: 99%

“…Recently, it has been demonstrated that (NHC)Pdbased systems catalyze vinyl-addition polymerization of various functionalized norbornenes [14][15][16][17][18][19][20][21]. For instance, these systems showed good catalytic activity in polymerization of norbornenes with hydroxy [20,22], ether [21], ester [14,15,[18][19][20]23,24], imide [14,16,17], silyl [14,19,20,24], and alkyl/alkenyl [19,20,22,24,25] Intriguing results were obtained when studying the polymerization of M1-M4 on these (NHC)Pd-catalysts. The single-component catalyst [SIMesPd(cinn)(MeCN)] + BARF − showed very high activity in the polymerization of M2 and M4 monomers (Table 1).…”

Section: Vinyl-addition Polymerization Of 5-bromoalkylnorbornenesmentioning

confidence: 99%

Vinyl-Addition Homopolymeization of Norbornenes with Bromoalkyl Groups

Lunin,

Andreyanov,

Makarov

et al. 2023

Polymers

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Vinyl-addition polynorbornenes are of great interest as versatile templates for the targeted design of polymer materials with desired properties. These polymers possess rigid and saturated backbones, which provide them with high thermal and chemical stability as well as high glass transition temperatures. Vinyl-addition polymers from norbornenes with bromoalkyl groups are widely used as precursors of anion exchange membranes; however, high-molecular-weight homopolymers from such monomers are often difficult to prepare. Herein, we report the systematic study of vinyl-addition polymerization of norbornenes with various bromoalkyl groups on Pd-catalysts bearing N-heterocyclic carbene ligands ((NHC)Pd-systems). Norbornenes with different lengths of hydrocarbon linker (one, two, and four CH2 groups) between the bicyclic norbornene moiety and the bromine atom were used as model monomers, while single- and three-component (NHC)Pd-systems were applied as catalysts. In vinyl-addition polymerization, the reactivity of the investigated monomers varied substantially. The relative reactivity of these monomers was assessed in copolymerization experiments, which showed that the closer the bromine is to the norbornene double-bond, the lower the monomer’s reactivity. The most reactive monomer was the norbornene derivative with the largest substituent (with the longest linker). Tuning the catalyst’s nature and the conditions of polymerization, we succeeded in synthesizing high-molecular-weight homopolymers from norbornenes with bromoalkyl groups (Mn up to 1.4 × 106). The basic physico-chemical properties of the prepared polymers were studied and considered together with the results of vinyl-addition polymerization.

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“…Considering different cycloolefins, norbornenes attract the attention of researchers as model monomers for catalytic activity tests and as building blocks for new polymeric materials owing to the diversity of norbornene chemistry, their availability, and the high reactivity of norbornene double bonds. A huge number of two- and three-component systems based on transition metal salts which are the most widely used catalysts for VAP of norbornenes ,,,,− have been developed. However, these systems have a number of known disadvantages when compared to single-component catalysts. ,, At the same time, single-component catalysts for VAP of norbornenes are rare, and single-component catalysts capable of catalyzing living VAP of norbornenes are scarce.…”

Section: Introductionmentioning

confidence: 99%

Air-Stable Single-Component Pd-Catalysts for Vinyl-Addition Polymerization of Functionalized Norbornenes

et al. 2022

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Well-defined single-component and tolerant Ru-, Mo-, and W-catalysts have been earlier developed for ring-opening metathesis polymerization of norbornene and its derivatives. Another way of norbornene polymerization�vinyl-addition polymerization (VAP)�is a more thermodynamically favorable process and gives polymers with saturated and rigid main chains. Single-component catalysts for VAP are required, which combine good activity, tolerance to functional groups, resistance to oxygen, and air moisture and are capable of catalyzing living VAP of norbornenes. Herein, we have shown that cationic Pd-complexes with N-heterocyclic carbene ligands (NHC ligands) and weak coordinating anion ligands ([(NHC)Pd(allyl)L] + A − , where allyl is an allyl group, L = CO, CH 3 CN, CH 2 Cl 2 , and A − = SbF 6 − or BARF − ) are highly efficient single-component catalysts for VAP of both norbornene and various substituted norbornenes. These complexes, being stable in the solid state and in solutions, have exhibited several important features as VAP catalysts. They are capable of catalyzing VAP of norbornenes in air and are tolerant to functional groups. The complexes have shown high catalytic activity and have allowed polymerizing monomers at very low catalyst loadings, as low as 2 ppm. The versatility of [(NHC)Pd(allyl)L] + A − complexes as catalysts of VAP has been demonstrated by successful polymerization of monomers with polar and bulky groups, containing alkyl, vinyl, alkylidene, ether, ester, imide, or organosilicon motifs, affording high-molecular-weight products in good and high yields. Tuning the nature of NHC and allyl ligands in [(NHC)Pd(allyl)L] + A − complexes let perform living VAP, yielding block copolymers.

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Polymerization of 5-norbornene-2-methyl acetate catalyzed by air-stable cationic (η3-substituted allyl) palladium complexes of N-heterocyclic carbene

Cited by 34 publications

References 65 publications

Polymerization of 5-Alkylidene-2-norbornenes with Highly Active Pd–N-Heterocyclic Carbene Complex Catalysts: Catalyst Structure–Activity Relationships

Polymerization of 5-Alkylidene-2-norbornenes with Highly Active Pd–N-Heterocyclic Carbene Complex Catalysts: Catalyst Structure–Activity Relationships

Vinyl-Addition Homopolymeization of Norbornenes with Bromoalkyl Groups

Air-Stable Single-Component Pd-Catalysts for Vinyl-Addition Polymerization of Functionalized Norbornenes

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