Synthesis of a sequence-controlled in-chain alkynyl/tertiary amino dual-functionalized terpolymer via living anionic polymerization

2018 ◽  
Vol 9 (1) ◽  
pp. 108-120 ◽  
Author(s):  
Lincan Yang ◽  
Hongwei Ma ◽  
Li Han ◽  
Xinyu Hao ◽  
Pibo Liu ◽  
...  
Keyword(s):  
Anionic Polymerization ◽  
Kinetic Characteristics ◽  
Living Anionic Polymerization ◽  
Sequence Structure ◽  
H Nmr ◽  
Nmr Method ◽  
Tertiary Amino

A dual-functionalized sequence-defined terpolymer was synthesized via living anionic polymerization; meanwhile its kinetic characteristics and sequence structure were investigated in detail via the in situ1H NMR method.

Revision of the structure of 3-methoxy-14α-hydroxy-D-homo-1,3,5-(10)-estratrien-17a-one. A simple 1H NMR method for the determination of configuration of hydroxy group in position 5 and/or 14 of the D-homo-steroid skeleton

1991 ◽  
Vol 56 (7) ◽  
pp. 1512-1524 ◽  
Author(s):  
Miloš Buděšínský ◽  
Alexander Kasal ◽  
Želimír Procházka ◽  
Huynh Kim Thoa ◽  
Soňa Vašíčková ◽  
...  
Keyword(s):  
Hydroxy Group ◽  
Chemical Shifts ◽  
Cotton Effect ◽  
Hydroxyl Group ◽  
H Nmr ◽  
Nmr Method ◽  
Synthetic Models ◽  
Steroid Skeleton

Eignerova and Prochazka found in 1974 the Cotton effect value for 3-methoxy-14α-hydroxy-D-homo-1,3,5(10)-estratrien-17a-one (Ia) to be Δε – 2.76.Calculation of the Δε value for this compound led, however, to a substantially lower value, which suggested the hypothesis that the compound was in fact rather an epimer with the hydroxy group in position 14β. This hypothesis was studied by means of 1H NMR spectra of synthetic models, using the changes of the chemical shifts of angular methyls, induced by in situ acylation of the angular hydroxyl with an α- or β-configuration with trichloroacetyl isocyanate (TAI). The observed TAI-acylation shifts on model compounds indicated the structure Ib with a 14b-configuration of the hydroxyl group. Indenpendent proof has been given by the synthesis of both 14-hydroxy epimers, Ia and Ib. A simple 1H NMR method is proposed for the determination of configuration of the hydroxyl in position 5 or 14 of D-homo-steroid skeleton.

Lithiated Thiaacetals as Initiators for Living Anionic Polymerization of Diene Elastomers: Polymerization and Compounding

2007 ◽  
Vol 80 (2) ◽  
pp. 194-211 ◽  
Author(s):  
Terrence E. Hogan ◽  
Yuan-Yong Yan ◽  
William L. Hergenrother ◽  
David F. Lawson
Keyword(s):  
Polymer Chain ◽  
Anionic Polymerization ◽  
Polydispersity Index ◽  
Methyl Substituent ◽  
Living Anionic Polymerization ◽  
Model Studies ◽  
Polymerization Mixture ◽  
Procedure Model

Abstract Polybutadiene and poly(butadiene-co-styrene) elastomers were prepared in high conversions using 2-lithio-2- methyl-1,3-dithiane as the initiator. Polymers were readily prepared with a polydispersity index (PDI) of 1.05 to 1.26 and a Mn of up to 208 kg/mol. The replacement of the 2-methyl substituent with phenyl, trimethylsilyl or 4-dimethylamino phenyl also gave active initiators that incorporated at the head of the chain. However, initiation rates appeared to vary somewhat with the structure of the initiators. The polymerizations obtained are in all cases controlled and apparently living with the live chain ends capable of further reactions. The initiators could be generated prior to addition to the polymerization mixture or by an in-situ procedure. Model studies gave evidence that the dithiane chain end can be opened under cure conditions and react with unsaturation present in the polymer chain. Several of the product polymers were found to impart improved hysteresis to carbon and silica-filled rubbery vulcanizates possibly through an endlinking mechanism.

Mechanistische Untersuchungen zum reversiblen Gleichgewicht von metallorganischen Tripeldecker- und Sandwichkomplexen des Typs [Bis{(η5-CpR)Co}-μ-{η4:η4-aren}] und [(η5-CpR)Co(η6-aren)] / Mechanistic Studies towards the Reversible Equilibrium between Metal Organic Triple Decker and Sandwich Complexes [Bis{(η5 -CpR)Co}-μ-{η4 :η4-arene}] and [{(η5-CpR)Co(η6-arene)]

1998 ◽  
Vol 53 (11) ◽  
pp. 1267-1272 ◽  
Author(s):  
Jörg J. Schneider ◽  
Dirk Wolf
Keyword(s):  
Ligand Exchange ◽  
Sandwich Complexes ◽  
Valuable Metal ◽  
H Nmr ◽  
Synthetic Utility ◽  
Metal Organic ◽  
Arene Ligand ◽  
Benzene Toluene

The arene ligand exchange mechanism of slipped arene triple deckers [Bis{(η5-CpR)Co}-μ-{η4:η4-arene}] (R = Me5, 1,2,4 tri-tert butyl, arene = benzene, toluene) 1 was studied by 1H-NMR spectroscopy for different concentrations and solvents. It has been found that triple deckers of type 1 decompose slowly in solution. A unique equilibrium, between these triple deckers and the mixed sandwich complexes [(η6-arene)Co(η5-CpR)] and 14 e [(η5-Cp)Co]solv fragments generated in situ by decomposition o f 1 exists. In addition to this equilibrium arene lability of the thus formed mixed sandwich complex type has been detected by NMR making slipped triple deckers 1 ideal single source compounds for the generation of two [(η5-Cp)Co] fragments in one reaction step. Such fragments are valuable metal ligand components with high synthetic utility in organometallic chemistry.

Living Anionic Polymerization of 4-Halostyrenes

2021 ◽  
Vol 54 (3) ◽  
pp. 1489-1498
Author(s):  
Raita Goseki ◽  
Taro Koizumi ◽  
Reina Kurakake ◽  
Satoshi Uchida ◽  
Takashi Ishizone
Keyword(s):  
Anionic Polymerization ◽  
Living Anionic Polymerization

Living Anionic Polymerization ofN-Methacryloyl-2-methylaziridine

2009 ◽  
Vol 279 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Takashi Ishizone ◽  
Jun-ichi Kusakabe ◽  
Takashi Suzuki
Keyword(s):  
Anionic Polymerization ◽  
Living Anionic Polymerization
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