V.–THE LATER MIDDLE AGES, i1200‐c. 1530

Pugh, Tison

doi:10.1111/j.1467-8314.1955.tb00291.x

Cited by 2 publications

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“…We are interested in the direct coupling of aryl groups through an acetylene unit, but with well defined diarylacetylene sequences. As models for polymerization reactions of this type, we have prepared the symmetrically and asymmetrically subsituted 1,2-(4,4'-dialkyloxyary1)-acetylene monomers (9)(10)(11)(12) and 1,4-bis[2-(4',4"-dialkyloxyaryl)ethynyl]-benzene dimers (9,13,14) shown in Scheme 2 by a three step, one pot, solid-liquid phase transfer Pd(O)/Cu(I) catalyzed coupling of 2-methyl-3-butyn-2-01 with aryl halides deactivated by electrondonating groups.…”

Section: A R V L -A C E T U U~m H U W and N Smentioning

confidence: 99%

Pd(0) and Ni(0) catalyzed polymerization reactions

Percéc

Pugh

Cramer

et al. 1992

Makromolekulare Chemie. Macromolecular Symposia

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Three novel metal catalyzed cross‐coupling polymerization reactions which result in carbon‐carbon bond formation are described and discussed in context with other metal catalyzed cross‐coupling polymerization reactions. Diarylacetylene monomers and dimers are prepared by the phase transfer Pd(0)/Cu(I) catalyzed coupling of aryl halides with 2‐methyl‐3‐butyn‐2‐ol. Aryl‐alkyl bond forming polymerization reactions are achieved by the phase transfer Pd(0) catalyzed coupling of B‐alkyl‐9‐borabicyclo[3.3.1]nonane derivatives with aryl halides. Soluble polyphenylenes are prepared by the Ni(0) catalyzed homocoupling of substituted phenylenebistriflates in the presence of zinc.

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Section: A R V L -A C E T U U~m H U W and N Smentioning

confidence: 99%

Pd(0) and Ni(0) catalyzed polymerization reactions

Percéc

Pugh

Cramer

et al. 1992

Makromolekulare Chemie. Macromolecular Symposia

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“…In most cases, the chiral center is located near the mesogenic molecular part either in the spacer or in the terminal alkyl chain. However, some reports describe the synthesis of side-chain liquid crystal polymers having chiral centers in their backbones [ll-141. The synthesis of a new type of side-chain liquid crystalline polyethers by chemical modification of atactic polyepichlorohydrin (PECH) with a variety of mesogens was first reported by Pugh and Percec [15]. On the basis of differential scanning calorimetry (DSC) analysis, they concluded that at and above a degree of substitution of about 30% the copolyethers all exhibit liquid crystal properties.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and thermal properties of side‐chain liquid crystalline polyethers with racemic and chiral backbone

Taton

Borgne

Spassky

et al. 1994

Polymers for Advanced Techs

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Racemic and chiral [(4-cyano-4'-biphenyl)oxyl and [(4methoxy-4'-biphenyl~oxylmethyloxiranes were prepared from racemic epichlorohydrin or racemic and chiral glycidols and polymerized in dimethylsulfoxide (DMSO) with Bu'OK as the initiator system. Initial phase identifications were made by differential scanning calorimetry (DSC) and optical microscopy techniques and confirmed by X-ray diffraction measurements. Upon heating, all the monomers show only a crystal-isotropic phase transition. The racemic and chiral [(4-cyano-4'-bipheny1)oxylmethyloxiranes exhibit a nematic and a cholesteric monotropic phase, respectively. Methoxybiphenyl substituted polyethers are crystalline and insoluble in virtually all common solvents. Cyanobiphenyl substituted polyethers are soluble under the same experimental conditions and show enantiotropic liquid crystalline properties. The racemic polymer exhibits a nematic phase, while the optically active polymer forms a cholesteric phase.

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V.–THE LATER MIDDLE AGES, i1200‐c. 1530

Cited by 2 publications

References 0 publications

Pd(0) and Ni(0) catalyzed polymerization reactions

Pd(0) and Ni(0) catalyzed polymerization reactions

Synthesis and thermal properties of side‐chain liquid crystalline polyethers with racemic and chiral backbone

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