scholarly journals Insight into the synthesis of N-methylated polypeptides

2020 ◽  
Vol 11 (43) ◽  
pp. 6919-6927
Author(s):  
Christian Muhl ◽  
Lydia Zengerling ◽  
Jonathan Groß ◽  
Paul Eckhardt ◽  
Till Opatz ◽  
...  
Keyword(s):  
Amino Acids ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Insight Into

The ring-opening polymerization of α-substituted N-methylated N-carboxy anhydrides is reported. The polymerization was tested using various amino acids and initiators, and was found to be limited by the steric demand of N-methylated compared to conventional amino acids.

Biodegradable Polymers Derived from Amino Acids for Biological Applications

2010 ◽  
Vol 76 ◽  
pp. 30-35 ◽  
Author(s):  
Naomi Cohen-Arazi ◽  
Ilanit Hagag ◽  
Michal Kolitz ◽  
Abraham J. Domb ◽  
Jeoshua Katzhendler
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Ring Opening ◽  
Building Blocks ◽  
Ring Opening Polymerization ◽  
Microwave Assisted Synthesis ◽  
Hydroxy Acids ◽  
Natural Amino Acids ◽  
Direct Condensation ◽  
Positively Charged

Optically active α-hydroxy acids derived from amino acids have been synthesized and polymerized into new biodegradable polyesters. The variety of functional side chains enables the design of positively charged, negatively charged, hydrophobic and hydrophilic chiral building blocks or any combination of these constituents. Hydroxy acids of 15 natural amino acids were prepared with retention of configuration using a straightforward and reliable method of diazotization of α-amino acids. Polyesters were synthesized from these hydroxy acids by a number of methods: direct condensation in bulk, microwave assisted synthesis and ring opening polymerization. The molecular weight of the prepared polymers ranges between 2000 to 5000Da for the direct condensation and the microwave methods, whereas the ring opening polymerization results in high molecular weight polymers (20000 to 30000Da). The polymers were analyzed for their optical activity (Circular Dichroism Spectroscopy), thermal properties (DSC), solubility, molecular weight and polydispersity (GPC), and aqueous degradation. These polymers were tested for their compatibility to neuronal cells growth and differentiation.

A New Insight Into the Mechanism of the Ring-Opening Polymerization of Trimethylene Carbonate Catalyzed by Methanesulfonic Acid

2012 ◽  
Vol 214 (1) ◽  
pp. 85-93 ◽  
Author(s):  
João M. Campos ◽  
Maria R. Ribeiro ◽  
Maria F. Ribeiro ◽  
Alain Deffieux ◽  
Frédéric Peruch
Keyword(s):  
Ring Opening ◽  
Methanesulfonic Acid ◽  
Ring Opening Polymerization ◽  
Trimethylene Carbonate ◽  
Insight Into

Multiblock silicones, 1 Vinyl functionalized polydimethylsiloxane a

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Carine Ivanenko ◽  
Catherine Maitre ◽  
François Ganachaud ◽  
Patrick Hémery
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Multiblock Copolymers ◽  
Chain Reactions ◽  
Anionic Ring ◽  
Interface Propagation ◽  
Dispersed Media ◽  
Insight Into

Abstract The first part of this series is devoted to the preparation of vinyl functionalized multiblock silicones by the process of anionic ring opening polymerization in miniemulsion. The advantage of working in dispersed media is that different scales of reactivities are found between one-chain reactions, taking place at the interface (propagation, backbiting), and two-chain reactions, located in the bulk of the particles (polycondensation and intermolecular redistribution). First, homopolymerizations of octamethylcyclotetrasiloxane (D4) and tetramethyltetravinylcyclotetrasiloxane (D4 V) were carried out and compared, focusing specifically on the rates of polymerization, backbiting and polycondensation processes. Copolymerization of D4 with D4 V then gave insight into the extent of mixed cycles’ formation and particularly how to avoid these. On this basis, recipes were carefully selected so that homopolymerization and scarce co-polycondensation and redistribution progress at the expense of backbiting reactions and thus multiblock copolymers are formed, the microstructure of which was confirmed with 29Si NMR.

scholarly journals Mechanistic Insight into the Ring-Opening Polymerization of ɛ-Caprolactone and L-Lactide Using Ketiminate-Ligated Aluminum Catalysts

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1530 ◽  
Author(s):  
Lin ◽  
Jheng
Keyword(s):  
Thermal Effects ◽  
Ring Opening ◽  
Density Functional ◽  
Bond Cleavage ◽  
Ring Opening Polymerization ◽  
Catalyst Design ◽  
Reaction Conditions ◽  
Functional Theory ◽  
Cleavage Step ◽  
Insight Into

The reactivity and the reaction conditions of the ring-opening polymerization of ɛ-caprolactone (ɛ-CL) and L-lactide (LA) initiated by aluminum ketiminate complexes have been shown differently. Herein, we account for the observation by studying the mechanisms on the basis of density functional theory (DFT) calculations. The calculations show that the ring-opening polymerization of ɛ-CL and LA are rate-determined by the benzoxide insertion and the C–O bond cleavage step, respectively. Theoretical computations suggest that the reaction temperature of L–LA polymerization should be higher than that of ɛ-CL one, in agreement with the experimental data. To provide a reasonable interpretation of the experimental results and to give an insight into the catalyst design, the influence of the electronic, steric, and thermal effects on the polymerization behaviors will be also discussed in this study.

Ring opening polymerization of α-amino acids: advances in synthesis, architecture and applications of polypeptides and their hybrids

2020 ◽  
Vol 49 (14) ◽  
pp. 4737-4834 ◽  
Author(s):  
Alicia Rasines Mazo ◽  
Stephanie Allison-Logan ◽  
Fatemeh Karimi ◽  
Nicholas Jun-An Chan ◽  
Wenlian Qiu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Ring Opening ◽  
Biomedical Applications ◽  
Architectural Design ◽  
Ring Opening Polymerization ◽  
Comprehensive Overview

This review provides a comprehensive overview of the latest advances in the synthesis, architectural design and biomedical applications of polypeptides and their hybrids.

scholarly journals Back Cover: Insight into the Thermal Ring-Opening Polymerization of Phospha[1]ferrocenophanes (Chem. Eur. J. 47/2016)

2016 ◽  
Vol 22 (47) ◽  
pp. 17048-17048 ◽  
Author(s):  
Elaheh Khozeimeh Sarbisheh ◽  
Jose Esteban Flores ◽  
Jianfeng Zhu ◽  
Jens Müller
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Back Cover ◽  
Insight Into

scholarly journals Well-defined (co)polypeptides bearing pendant alkyne groups

2016 ◽  
Vol 7 (21) ◽  
pp. 3487-3491 ◽  
Author(s):  
Wei Zhao ◽  
Yves Gnanou ◽  
Nikos Hadjichristidis
Keyword(s):  
Amino Acids ◽  
Hydrogen Bonding ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Metal Free

A novel metal-free strategy, using hydrogen-bonding catalytic ring opening polymerization of alkyne-functionalized N-carboxy anhydrites of α-amino acids, was developed for the synthesis of well-defined polypeptides bearing pendant alkyne groups.

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