Poly[glycidyl oligo(oxyethylene)carbamate]s (PGn-EOmR’ and R-PGn-EOmR’): Controlled Synthesis and Effects of Molecular Parameters (n and m), Side Group (R’), and End-Group (R) on Thermoresponsive Property

2021 ◽  
Author(s):  
Tingyu He ◽  
Yanqiu Wang ◽  
Liang Xu ◽  
Xiangming Fu ◽  
Atsushi Narumi ◽  
...  
Keyword(s):  
Ring Opening ◽  
Glycidyl Ether ◽  
Controlled Synthesis ◽  
Side Chains ◽  
Side Group ◽  
Molecular Parameters ◽  
End Group

The controlled syntheses of glycerol-based polymers that consist of poly(glycidol) (PG)-backbones and thermoresponsive oligo(oxyethylene)-side chains are described. The organocatalytic ring-opening polymerizations of benzyl glycidyl ether (BnGE) were performed to produce...

scholarly journals Lactones in the Synthesis of Prostaglandins and Prostaglandin Analogs

2021 ◽  
Vol 22 (4) ◽  
pp. 1572
Author(s):  
Constantin Tănase ◽  
Lucia Pintilie ◽  
Raluca Elena Tănase
Keyword(s):  
Biological Role ◽  
Controlled Synthesis ◽  
Side Chains ◽  
Enzymatic Resolution ◽  
Marine Mollusc ◽  
Enantioselective Reactions ◽  
The Many ◽  
Key Steps

In the total stereo-controlled synthesis of natural prostaglandins (PGs) and their structural analogs, a vast class of compounds and drugs, known as the lactones, are encountered in a few key steps to build the final molecule, as: δ-lactones, γ-lactones, and 1,9-, 1,11-, and 1,15-macrolactones. After the synthesis of 1,9-PGF2α and 1,15-PGF2α lactones, many 1,15-lactones of E2, E3, F2, F3, A2, and A3 were found in the marine mollusc Tethys fimbria and the quest for understanding their biological role stimulated the research on their synthesis. Then 1,9-, 1,11-, and 1,15-PG lactones of the drugs were synthesized as an alternative to the corresponding esters, and the first part of the paper describes the methods used for their synthesis. The efficient Corey procedure for the synthesis of prostaglandins uses the key δ-lactone and γ-lactone intermediates with three or four stereocenters on the cyclopentane fragment to link the PG side chains. The paper describes the most used procedures for the synthesis of the milestone δ-Corey-lactones and γ-Corey-lactones, their improvements, and some new promising methods, such as interesting, new stereo-controlled and catalyzed enantioselective reactions, and methods based on the chemical/enzymatic resolution of the compounds in different steps of the sequences. The many uses of δ-lactones not only for the synthesis of γ-lactones, but also for obtaining 9β-halogen-PGs and halogen-substituted cyclopentane intermediates, as synthons for new 9β-PG analogs and future applications, are also discussed.

Synthesis of binary-patterned brushes by combining atom transfer radical polymerization and ring-opening polymerization

e-Polymers ◽  
2013 ◽  
Vol 13 (1) ◽  
Author(s):  
Aurore Olivier ◽  
Franck Meyer ◽  
Jean-Marie Raquez ◽  
Philippe Dubois
Keyword(s):  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Ring Opening ◽  
Microcontact Printing ◽  
Gold Surface ◽  
Ring Opening Polymerization ◽  
Careful Study ◽  
Atom Transfer ◽  
Final Thickness ◽  
End Group

Abstract This paper report the synthesis of binary-patterned brushes, combining two distinctive surface initiated-polymerizations (SIP) on the basis of different propagating species: the SI Ring Opening Polymerization (ROP) of L-Lactide (LLA) and SI atom transfer radical polymerization (ATRP) of N,N’-dimethylaminoethyl methacrylate (DMAEMA) on gold surface. First of all, a careful study of surfaceinitiated ROP of L-Lactide from hydroxyl end-group of thiol monolayer on gold surface as catalyzed by metal-free catalyst was carried out. The PLLA brushes synthesis was evaluated using two types of thiol monolayer and revealed the influence of ROP initiator chain length on the final thickness of the PLLA film. Combining the soft lithographic technique, microcontact printing, and the liquid phase deposition, the deposition onto specific micro-domains of both initiators was performed. The growth of PDMAEMA brushes and PLLA brushes was conducted by successive ATRP and ROP.

Poly(dendrimers) with Phosphorescent Iridium(III) Complex-Based Side Chains Prepared via Ring-Opening Metathesis Polymerization

2012 ◽  
Vol 45 (7) ◽  
pp. 2963-2971 ◽  
Author(s):  
Wen-Yong Lai ◽  
Michael N. Balfour ◽  
Jack W. Levell ◽  
Ashu K. Bansal ◽  
Paul L. Burn ◽  
...  
Keyword(s):  
Ring Opening ◽  
Side Chains ◽  
Ring Opening Metathesis Polymerization ◽  
Metathesis Polymerization

Tuning the luminescence efficiency by perfluorination of side chains in Eu3+ complexes with β-diketones of thiophene series

2021 ◽  
Author(s):  
Evgeniya Varaksina ◽  
Mikhail A. Kiskin ◽  
Konstantin A. Lyssenko ◽  
Lada N. Puntus ◽  
Vladislav Korshunov ◽  
...  
Keyword(s):  
Comparative Study ◽  
Thiophene Ring ◽  
Luminescent Properties ◽  
Side Chains ◽  
Side Group ◽  
Luminescence Efficiency ◽  
Thiophene Series ◽  
Gadolinium Complexes

A series of europium and gadolinium complexes comprising β-diketone moiety modified with a fluorinated side-group and thiophene ring have been designed, synthesized and a comparative study of their luminescent properties...

Bio-based polyesters synthesized by ring-opening copolymerizations of eugenyl glycidyl ether and cyclic anhydrides using a binuclear [OSSO]CrCl complex

2020 ◽  
Vol 22 (17) ◽  
pp. 5742-5750
Author(s):  
Binyuan Liu ◽  
Junwu Chen ◽  
Ning Liu ◽  
Huining Ding ◽  
Xianmin Wu ◽  
...  
Keyword(s):  
Ring Opening ◽  
Glycidyl Ether ◽  
Cyclic Anhydrides

A series of bio-based polyesters are efficiently synthesized by ring-opening copolymerizations of eugenyl glycidyl ether and various cyclic anhydrides using a binuclear [OSSO]CrCl complex in conjuction with PPNCl.

scholarly journals Concise Synthesis of Macrocycles by Multicomponent Reactions

Synthesis ◽  
2018 ◽  
Vol 50 (05) ◽  
pp. 1027-1038 ◽  
Author(s):  
Alexander Dömling ◽  
Eman Abdelraheem ◽  
Samad Khaksar
Keyword(s):  
Amino Acid ◽  
Multicomponent Reaction ◽  
Ring Opening ◽  
Multicomponent Reactions ◽  
Reaction Pathway ◽  
Ring Closure ◽  
Side Chains ◽  
Reaction Sequence ◽  
Cyclic Anhydride

A short reaction pathway was devised to synthesize a library of artificial 18–27-membered macrocycles. The five-step reaction sequence involves ring opening of a cyclic anhydride with a diamine, esterification, coupling with an amino acid isocyanide, saponification, and, finally, macro-ring closure using an Ugi or, alternatively, a Passerini multicomponent reaction. Three out of the five steps allow for the versatile introduction of linker elements, side chains, and substituents with aromatic, heteroaromatic, and aliphatic character. The versatile pathway is described for 15 different target macrocycles on a mmol scale. Artificial macrocycles have recently become of great interest due to their potential to bind to difficult post-genomic targets.

scholarly journals Ring-opening polymerization of monosubstituted oxiranes in the presence of potassium hydride: determination of initiation course and structure of macromolecules by MALDI-TOF mass spectrometry

2019 ◽  
Vol 26 (12) ◽  
Author(s):  
Zbigniew Grobelny ◽  
Justyna Jurek-Suliga ◽  
Sylwia Golba
Keyword(s):  
Mass Spectrometry ◽  
Ring Opening ◽  
Glycidyl Ether ◽  
Ring Opening Polymerization ◽  
Size Exclusion ◽  
Oxirane Ring ◽  
Maldi Tof ◽  
Glycidyl Ethers ◽  
Initiation Step ◽  
Potassium Hydride

AbstractSeveral monosubstituted oxiranes were polymerized with suspension of potassium hydride (KH) in tetrahydrofuran (THF) at room temperature. This heterogeneous process resulted in polyethers with various starting groups depending on the kind of monomer. The macromolecules formed in ring-opening polymerization of monosubstituted oxiranes were analyzed by Matrix Assisted Laser Desorption/Ionization - Time of Flight Mass Spectrometry (MALDI-TOF MS). It was stated, that initiation of propylene oxide (PO) polymerization with KH proceeded via three ways, i.e. cleavage of oxirane ring in the β-position, monomer deprotonation and deoxygenation. Potassium isopropoxide, potassium allyloxide and potassium hydroxide were the real initiators. The main reactions, which occur in the initiation step, depend on the type of monomer used. In the case of allyl glycidyl ether (AGE) and phenyl glycidyl ether (PGE) deprotonation of the monomer did not occur. During initiation of glycidyl ethers oxirane ring was opened and also linear ether bond between glycidyl group and oxygen atom was cleaved under influence of KH. Interestingly, formation of new kinds of macromolecules was observed in the systems containing glycidyl ethers, which do not possess mers of the monomers used. Mechanisms of the studied processes were presented and discussed. Carbon-13 Nuclear Magnetic Resonance (13C NMR) was used as supporting technique for analysis of the obtained polymers. Number average molar masses of the polymers (Mn) determined by Size Exclusion Chromatography (SEC) were about two times higher than calculated ones. It indicated that half of used KH did not take part in the initiation step.

scholarly journals New way of anionic ring-opening copolymerization of β-butyrolactone and ε-caprolactone: determination of the reaction course

2020 ◽  
Vol 27 (12) ◽  
Author(s):  
Zbigniew Grobelny ◽  
Justyna Jurek-Suliga ◽  
Sylwia Golba
Keyword(s):  
Ring Opening ◽  
Chemical Structure ◽  
Side Reactions ◽  
Complexing Agent ◽  
Critical Approach ◽  
Anionic Ring ◽  
Tetrahydrofuran Solution ◽  
End Group ◽  
C Nmr

Abstract Poly(ε-caprolactone)-block-poly(β-butyrolactone) copolymers were prepared in two-step synthesis. Firstly, poly(ε-caprolactone) (PCL) was obtained by anionic ring-opening polymerization of CL initiated with anhydrous KOH activated 12-crown-4 cation complexing agent. Reaction was carried out in tetrahydrofuran solution and argon atmosphere at room temperature. Then, β-butyrolactone (BL) and 18-crown-6 were added to the system, resulting in PCL-block-PBL copolymer, which contains after methylation hydroxyl starting group and methyl ester end group. The main product was contaminated with PCL and PBL homopolymers formed in a side reactions. 13C NMR technique was used for determination of chemical structure of polymers obtained. The course of the studied processes was proposed. MALDI-TOF technique was used to reveal the macromolecules’ architecture where several series were found. The identified series shown that mainly copolymeric macromolecules were formed with scare contribution of homopolymeric polybutyrolactone with trans-crotonate starting groups and polycaprolactone, which is congruent with the proposed reaction mechanism. Moreover, critical approach concerning previously reported PCL-block-PBL copolymer synthesis by use of NaH as initiator was also presented.

Regioselective Ring-Opening Metathesis Polymerization of 3-Substituted Cyclooctenes with Ether Side Chains.

2016 ◽  
Vol 49 (7) ◽  
pp. 2493-2501 ◽  
Author(s):  
Shingo Kobayashi ◽  
Kousaku Fukuda ◽  
Maiko Kataoka ◽  
Masaru Tanaka
Keyword(s):  
Ring Opening ◽  
Side Chains ◽  
Ring Opening Metathesis Polymerization ◽  
Metathesis Polymerization

Cortical Reorganization in Dual Innervation by Single Peripheral Nerve

Neurosurgery ◽  
2017 ◽  
Vol 83 (4) ◽  
pp. 819-826
Author(s):  
Mou-Xiong Zheng ◽  
Yun-Dong Shen ◽  
Xu-Yun Hua ◽  
Ao-Lin Hou ◽  
Yi Zhu ◽  
...  
Keyword(s):  
Peripheral Nerve ◽  
Brachial Plexus ◽  
Phrenic Nerve ◽  
Nerve Transfer ◽  
Behavioral Observation ◽  
Cortical Reorganization ◽  
Side Group ◽  
Motor Representation ◽  
End To End ◽  
End Group

Abstract BACKGROUND Functional recovery after peripheral nerve injury and repair is related with cortical reorganization. However, the mechanism of innervating dual targets by 1 donor nerve is largely unknown. OBJECTIVE To investigate the cortical reorganization when the phrenic nerve simultaneously innervates the diaphragm and biceps. METHODS Total brachial plexus (C5-T1) injury rats were repaired by phrenic nerve–musculocutaneous nerve transfer with end-to-side (n = 15) or end-to-end (n = 15) neurorrhaphy. Brachial plexus avulsion (n = 5) and sham surgery (n = 5) rats were included for control. Behavioral observation, electromyography, and histologic studies were used for confirming peripheral nerve reinnervation. Cortical representations of the diaphragm and reinnervated biceps were studied by intracortical microstimulation techniques before and at months 0.5, 3, 5, 7, and 10 after surgery. RESULTS At month 0.5 after complete brachial plexus injury, the motor representation of the injured forelimb disappeared. The diaphragm representation was preserved in the “end-to-side” group but absent in the “end-to-end” group. Rhythmic contraction of biceps appeared in “end-to-end” and “end-to-side” groups, and the biceps representation reappeared in the original biceps and diaphragm areas at months 3 and 5. At month 10, it was completely located in the original biceps area in the “end-to-end” group. Part of the biceps representation remained in the original diaphragm area in the “end-to-side” group. Destroying the contralateral motor cortex did not eliminate respiration-related contraction of biceps. CONCLUSION The brain tends to resume biceps representation from the original diaphragm area to the original biceps area following phrenic nerve transfer. The original diaphragm area partly preserves reinnervated biceps representation after end-to-side transfer.

Sign in / Sign up

Export Citation Format

Share Document