Anionic catalytic systems for asymmetric synthesis of polymers

Natta, G.; Farina, Mário; Donati, M.

doi:10.1002/macp.1961.020430128

Cited by 78 publications

(26 citation statements)

References 6 publications

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“…The other relationship is the relative configuration between the vicinal carbon centers, also represented by the terms meso and racemo for a symmetrical structure, and by erythro and threo for an asymmetric structure. Among the possibilities of the formation of many kinds of stereoregular polymers from 1,4-disubstituted 1,3-butadiene monomers in Scheme 5, only two kinds of stereoregular polymers, that is, meso (or erythro)-diisotactic and racemo (or threo)-disyndiotactic polymers can be prepared by anionic polymerization with butyllithium in the absence or presence of alkylaluminum compounds, [101][102][103] or topochemical polymerization in the solid state. 39,48 The polymerization of organized monomers is useful for the control of polymer tacticity, although it is generally difficult to control the stereochemical structure of vinyl and diene polymers during radical polymerization in solution.…”

Section: Tacticitymentioning

confidence: 99%

Polymer Structure Control Based on Crystal Engineering for Materials Design

Matsumoto

2003

Polym J

111

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ABSTRACT:In this review article, polymer structure control and organic material design based on polymer crystal engineering are described. The structures and properties of crystalline materials are designed using pre-organized molecules through various intermolecular interactions such as hydrogen bonds, π · · · π, CH/π, CH/O, and halogen interactions. Here, we describe the features and mechanisms of the topochemical polymerization of 1,3-diene monomers including some ester, ammonium, and amide derivatives of muconic and sorbic acids, which are 1,3-diene di-and monocarboxylic acid derivatives, respectively. We have proposed the topochemical polymerization principles for diene monomers on the basis of the crystallographic data accumulated for various kinds of diene monomers. The combination of several intermolecular interactions is useful for the construction of molecular packing appropriate for 5 Å stacking in order to facilitate the topochemical polymerization in the crystalline state. We refer to the control of polymer chain structure including tacticity, molecular weight, and ladder structure, and also polymer crystal structures, as well as the organic intercalation system using layered polymer crystals obtained by the topochemical polymerization. A totally solvent-free system for the synthesis of layered polymer crystals is also described.KEY WORDS Topochemical Polymerization / Solid-State Reaction / Crystal Engineering / Supramolecular Synthon / Stereoregular Polymer / Controlled Radical Polymerization / X-Ray Single Crystal Structure Analysis / Intercalation / Controlled polymer synthesis, including the control of polymer chain structures such as molecular weight, molecular weight distribution, chain-end structure, branching, regioselectivity, and stereoselectivity, has great potential for the design of macromolecular architecture leading to advanced nano-materials and devices. [1][2][3][4][5][6][7][8][9][10][11] All the features and functions of polymers importantly depend on primary chain structures and the manner of polymer chain assembly in crystalline and non-crystalline solids, or in a condensed state. Therefore, the control of polymer chain structures in polymer synthesis can hardly be overestimated for the architecture of advanced polymeric materials.Especially, the stereochemistry of polymers has received significant attention in both fundamental and applied fields ever since the first discoveries of stereoregular polymers in the 1950s. 12-14 Highly controlled stereospecific polymerization has been well established by coordination polymerization of olefins and diene monomers and by anionic polymerization of certain types of polar monomers. Radical polymerization is the most important and convenient process for the production of various kinds of vinyl and diene polymers due to recent achievements in well-controlled polymerizations in addition to the classical advantages of the radical process. [15][16][17][18][19][20][21][22] There are two fundamentally different ways to control of the chain structu...

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Section: Tacticitymentioning

confidence: 99%

Polymer Structure Control Based on Crystal Engineering for Materials Design

Matsumoto

2003

Polym J

111

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“…As shown in Figure 1(a), an isotactic polymer thus produced possesses a mirror plane, if we ignore both its secondary structure (e.g., helicity)5, 6 and the small difference between the two chain ends (pseudo‐chirality). Accordingly, only a limited number of reports have appeared on the asymmetric synthesis of an optically active polymer from an achiral monomer through the control of the newly created chirotopic centers apart from helical chirality;7, 8 examples include the asymmetric polymerization of alkyl sorbate,9, 10 maleimide,11, 12 and epoxide or episulfide 13, 14. The synthesis of a helical polymer through the control of its plus or minus helicity has been the major interest in this area 7, 8, 15…”

Section: Chirality In Polymer Synthesismentioning

confidence: 99%

C‐reactive protein as a regulator of autoimmunity and inflammation

Clos

2003

Arthritis & Rheumatism

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Metal acetylacetonates are effective latent catalysts for epoxy/anhydride systems. A screen test on the catalytic behavior of metal acetylacetonate shows that this system offers a wide range of curing latency and material properties. It can be inferred that the curing behavior is closely related to the bonding strength of the metal ion to the ligand. Isothermal kinetic study on the catalytic behavior of metal chelates with first‐row transition metal ions is conducted and analyzed by using an autocatalytic model. It is found that the activation energy of the system containing the divalent metal chelates follows the Irving and Williams rule. The activation energies of the reaction obtained in the kinetic study are compared with the dissociation energies of the metal/ligand bond and the results are discussed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1572–1579, 2002

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“…( 11 ), having stereogenic carbon centers in the main chain [18] . The enantioselective anionic polymerization of 1,3 -dienes such as methyl and butyl 2,4 -hexadienoates (sorbates), and butyl styrylacrylates successfully proceeded in the presence of ((+) -2 -methylbutyl)lithium or BuLi/( − ) -menthyl ethyl ether [52] . 1,3 -Pentadiene also successfully underwent asymmetric polymerization in the presence of Et 3 Al/titanium tetra( − ) -menthoxide or (+) -tris(2 -methylbutyl)aluminum/Ti(OBu) 4 catalysts to give optically active polymers [53] .…”

Section: Methacrylatesmentioning

confidence: 99%