Makoto Ouchi

ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTTransition Metal-Catalyzed Living Radical Polymerization: Toward Perfection in Catalysis and Precision Polymer SynthesisMakoto Ouchi, Takaya Terashima, and Mitsuo Sawamoto*View Author Information Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan* To whom correspondence should be addressed. Phone: +81-75-383-2600. Fax: +81-75-383-2601. E-mail: [email protected]Cite this: Chem. R

In the past decade, living radical polymerization has provided one of the most versatile methods to precisely construct designed polymer architectures with complexity and polar functionality. This process takes advantage of carbon-radical intermediates, which tolerate a variety of functional groups in monomers and reaction media. "Transition metal-catalyzed living radical polymerization", one of these living systems, has widely been employed for precision polymer synthesis. Not only can this pro

Development of living polymerizations via reversible activation of dormant species opened the door to discovery of metal-catalyzed living radical polymerization that is now very useful for precise construction of tailor-made polymeric architectures. In this commemorative Perspective, the historical aspects as well as the prospects as a new polymerization tool are described toward advanced structural control or technological materials innovation in various fields.

For alternating repeat-unit sequence via living radical polymerization, “template monomers” were designed and polymerized, where two polymerizable alkene (vinyl) functions [e.g., methacrylate (M) and acrylate (A)] were placed side by side at the 1,8-positions on a rigid naphthalene scaffold. Even for such a divinyl monomer, highly selective intramolecular radical propagation was achieved with metal-catalyzed living radical polymerization systems, to give linear controlled polymers without cross-

Highly isotactic-specific cationic polymerization has been achieved for isobutyl vinyl ether (IBVE) with bis[(2,6-diisopropyl)phenoxy]titanium dichloride [TiCl2{OC6H4i-Pr2(2,6-)}2 (2)] as a Lewis acid catalyst (activator) to be coupled with the IBVE−HCl adduct (initiator). The polymerization, homogeneous and quantitative, was carried out in n-hexane at −78 °C in the presence of a bulky pyridine (2,6-di-tert-butyl-4-methylpyridine) to give isotactic-rich polymers with a meso dyad (m) = 90−92% (M̄

By utilizing features of the hemiacetal ester (HAE) bond: easy formation from vinyl ether and carboxylic acid and easy cleavage into different functional groups (-COOH and -OH), we achieved control of the alternating sequence of two functional pendant groups of a vinyl copolymer. Methacrylate- and acrylate-based vinyl groups were connected through HAE bonds to prepare a cleavable divinyl monomer, which was cyclo-polymerized under optimized conditions in a ruthenium-catalyzed living radical polym

In this review, four topics on alternating copolymers synthesized <italic>via</italic> chain-growth polymerization are reviewed: (1) how to control the alternating sequence; (2) sequence analysis; (3) self-assembly; and (4) functions.

An alternating copolymer of methacrylic acid and N-isopropyl acrylamide (NIPAM) was synthesized by selective cyclopolymerization of a special divinyl monomer and transformation of repeating cyclo-units in the resultant cyclopolymer. Crucial to the breakthrough is the monomer design in view of two types of cleavable bonds (3° ester and activated ester) in the pendant group of the monomer and the lower reactivity ratio of the two double bonds (methacrylate and electron-poor acrylate) for the polym

"Template initiator"' platforms (1) have been designed for expressing the sequence information in a template in radical polymerization. Thus, we demonstrated the structural adequacy of 1 consisting of two initiating sites placed ortho to each other in benzene: one for living cationic polymerization to introduce a template carrying substrate-recognition tags, and the other for metal-catalyzed living radical polymerization to achieve sequence regulation. For example, for two positional isomers wit

In this work, we achieved switching degradation of vinyl polymers made of a carbon-carbon bonded backbone. Crucial in this strategy was a small feed of methyl α-chloroacrylate (MCA) as the comonomer in radical polymerization of methyl methacrylate (MMA) so that the carbon-halogen bonds were introduced as the triggers for degradation. The "in-chain" trigger was activated by a one-electron redox metal catalyst as the chemical stimulus to generate the carbon-centered radical species, and subsequent

Stereoregulation in the cationic polymerization of various alkyl vinyl ethers was investigated with bis[(2,6-diisopropyl)phenoxy]titanium dichloride (1; catalyst) in conjunction with the HCl adduct of isobutyl vinyl ether as an initiator in n-hexane at −78 °C. The tacticities depended on the substituents of the monomers. Isobutyl and isopropyl vinyl ethers gave highly isotactic polymers (mm = 83%), whereas tert-butyl and n-butyl vinyl ethers resulted in lower isotactic contents (mm ∼ 50%) simila

Doppelt hält besser: Sich periodisch wiederholende ABA-Sequenzen in Copolymeren wurden mit einem monomeren Palladium-Templat erhalten. Wichtig für die Polymerisation waren π-π-Wechselwirkungen zwischen aromatischen Seitengruppen, um drei Vinylgruppen gezielt anzuordnen (siehe Bild). Aufgrund dieser Wechselwirkungen war doppelte Cyclopolymerisation am monomeren Palladium-Templat möglich. Entfernen des Templats ergab sequenzregulierte Copolymere. Detailed facts of importance to specialist readers