Palladium-Catalyzed Living/Controlled Vinyl Addition Polymerization of Cyclopropenes

Despite the various utilities of cyclopropenes (CPEs) in organic synthesis and ring-opening metathesis polymerization (ROMP), their vinyl addition polymerization has been sporadically explored, and the corresponding living/controlled polymerization remains a formidable challenge. The major obstacle is the intrinsic instability of the intermediate and the kinetic barrier for propagation. Herein a living/controlled vinyl addition polymerization of 3-methyl-3-carboxymethyl CPEs, catalyzed by [Pd(π-allyl)Cl]₂ ligated by a sulfinamide bisphosphine ligand, is demonstrated. A plot of the number-average molecular weight (M_n) versus the conversion was found to be linear during the polymerization, with the molecular weight dispersity (M_w/M_n) remaining narrow. The M_n values increased linearly with the increase in the initial feed ratio of monomer to catalyst. Furthermore, controlled block copolymerization via sequential monomer addition was successful. All of these points corroborate the living nature of this polymerization. The synergistic coordination action of the catalyst ligand and the lateral carbonyl group in the cyclopropene moiety plays a key role in achieving the efficient polymerization in a living/controlled manner.

Oligomerization and polymerization of 5-ethylidene-2-norbornene by cationic palladium and nickel catalysts

Nickel- and palladium-based catalyst systems were developed to convert 5-ethylidene-2-norbornene (ENB) to oligomers and polymers with highly controllable molecular weights.

Norbornene, norbornadiene and their derivatives: promising semi-products for organic synthesis and production of polymeric materials

The methods for synthesis of promising norbornene monomers from norbornadiene and quadricyclane are summarized. A strategy for their synthesis is discussed, combining theoretical and experimental approaches to the selection of catalysts and the conditions for carrying out stereoselective reactions. The mechanisms of catalytic reactions of synthesis of norbornene monomers, as well as the progress in the macromolecular design of functional polymeric materials based on them, are considered. The data on industrial processes of production of polynorbornenes and areas of their use are presented.

The bibliography includes 297 references.

Modulating polyolefin properties through the incorporation of nitrogen-containing polar monomers

In this work, ethylene copolymerization and terpolymerization reactions with some nitrogen-containing monomers were investigated using α-diimine palladium and phosphine-sulfonate palladium catalysts.

Phosphine-sulfonate-based nickel catalysts: ethylene polymerization and copolymerization with polar-functionalized norbornenes

A series of biaryl-based phosphine-sulfonate nickel catalysts are shown to mediate efficient ethylene polymerization and copolymerization with polar-functionalized norbornene comonomers.

High transparent alternate copolymer of norbornene with isoprene catalyzed by bis(phenoxy–imine) titanium complex

A bis(phenoxy–imine) titanium complex and Al(i-Bu)₃ were applied to obtain a novel highly transparent alternate copolymer of norbornene with isoprene.

[Pd(acac)(MeCN)2]BF4: air-tolerant, activator-free catalyst for alkene dimerization and polymerization

[Pd(acac)(MeCN)₂]BF₄ has been observed to catalyze selective substituted styrene dimerization and addition norbornene polymerization.