Video Experimental Relacionado

Updated: Jun 4, 2025

High-throughput Synthesis of Carbohydrates and Functionalization of Polyanhydride Nanoparticles

High-throughput Synthesis of Carbohydrates and Functionalization of Polyanhydride Nanoparticles

Published on: July 6, 2012

Copolimerización regioselectiva de epóxido alopiranósido derivado de glucosa con anhídridos cíclicos: desarrollo de

Jiaxi Xu¹, Jingjing Liu¹, Nikos Hadjichristidis¹

¹Polymer Synthesis Laboratory, Laboratory, Chemistry Program, KAUST Catalysis Center, Physical Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia.

Journal of the American Chemical Society

|December 19, 2024

Resumen

Este estudio introduce una nueva plataforma para crear poliésteres funcionalizados con azúcares uniformes utilizando copolimizaciones de apertura de anillos regioselectivas. Este avance permite un control preciso de las propiedades de los materiales y ofrece una nueva vía para la valiosa d-altrosa.

Área de la Ciencia:

Química de los polímeros
Química de los carbohidratos
Ciencias de los materiales

Sus antecedentes:

Los poliésteres uniformes funcionalizados con azúcar ofrecen ventajas significativas debido a las propiedades inherentes del azúcar y al potencial de postfuncionalización.
Los métodos de síntesis anteriores estaban limitados por la colocación irregular del grupo hidroxilo, lo que dificultaba el diseño preciso del material.

Objetivo del estudio:

Establecer la primera plataforma para la síntesis de poliésteres uniformes funcionalizados con azúcar.
Para permitir la síntesis controlada de poliésteres con una funcionalidad hidroxilo uniforme y propiedades materiales deseables.

Principales métodos:

Copolimerizaciones regioselectivas de apertura de anillos (ROCOP) del epoxido de alopiranosido anhidrosugar (derivado de la d-glucosa) con anhídridos cíclicos.
Desprotección selectiva completa para obtener los poliésteres finales.
Estudios mecanicistas mediante cálculos DFT, RMN y análisis HPLC.

Principales resultados:

Se obtienen poliésteres con pesos moleculares controlados y distribuciones de peso molecular estrechas (Đ < 1,19).
Los materiales sintetizados exhibieron altas temperaturas de transición de vidrio (hasta 188 °C) y una funcionalidad hidroxilo uniforme.
La degradación de los poliésteres proporcionó una ruta eficiente a la d-altrosa.
Se confirmó un ataque nucleófilo regioselectivo en la posición C2 del anillo de piranosa.
Se ha demostrado su incorporación en copolímeros multibloque uniformes funcionalizados con azúcar.

Conclusiones:

La plataforma ROCOP desarrollada proporciona un control preciso de la síntesis de poliéster funcionalizado con azúcar.
Estos poliésteres uniformes poseen propiedades ajustables y pueden elaborarse aún más en arquitecturas complejas de copolímero.
El método también presenta una vía valiosa para la producción de d-altrosa.

Más Videos Relacionados

Fabricating Degradable Thermoresponsive Hydrogels on Multiple Length Scales via Reactive Extrusion, Microfluidics, Self-assembly, and Electrospinning

Fabricating Degradable Thermoresponsive Hydrogels on Multiple Length Scales via Reactive Extrusion, Microfluidics, Self-assembly, and Electrospinning

Published on: April 16, 2018

Regioselective O-Glycosylation of Nucleosides via the Temporary 2',3'-Diol Protection by a Boronic Ester for the Synthesis of Disaccharide Nucleosides

Regioselective O-Glycosylation of Nucleosides via the Temporary 2',3'-Diol Protection by a Boronic Ester for the Synthesis of Disaccharide Nucleosides

Published on: July 26, 2018

Videos de Conceptos Relacionados

Types of Step-Growth Polymers: Polyesters

Types of Step-Growth Polymers: Polyesters

The introduction of polyesters has brought major development to the textile industry. The wrinkle-free behavior of polyester blends has eliminated the need for starching and ironing clothes.
Polyesters are commonly prepared from terephthalic acid and ethylene glycol; the crude product is known as poly(ethylene terephthalate) or PET. However, polyesters are synthesized industrially by transesterification of dimethyl terephthalate with ethylene glycol at 150 °C. The two reactants and the...

Step-Growth Polymerization: Overview

Step-Growth Polymerization: Overview

Step-growth or condensation polymerization is a stepwise reaction of bi or multifunctional monomers to form long-chain polymers. As all the monomers are reactive, most of the monomers are consumed at the early stages of the reaction to form small chains of reactive oligomers, which then combine to form long polymer chains in the late stages. Hence, the reaction has to proceed for a long time to achieve high molecular weight polymers.
Many natural and synthetic polymers are produced by...

Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)

Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)

Ring-opening metathesis polymerization or ROMP involves strained cycloalkenes as starting materials. The mechanism of ROMP proceeds by reacting cycloalkene with Grubbs catalyst to give metallacyclobutane intermediate which undergoes a ring-opening reaction to form new carbene. The new carbene reacts with another molecule of cycloalkene. Repetition of these steps leads to the formation of an unsaturated open-chain polymer product. All these steps are reversible, however, relieving the ring...

Preparation of Epoxides

Preparation of Epoxides

Overview
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of...

Oligosaccharide Assembly

Oligosaccharide Assembly

Protein glycosylation starts in the ER lumen and continues in the Golgi apparatus. Glycosyltransferases catalyze the addition of sugar molecules or glycosylation of proteins. Usually, these enzymes add sugars to the hydroxyl groups of selected serine or threonine residues to form O-linked glycans or the amino groups of asparagine residues to form N-linked glycans. Different positions on the same polypeptide chain can contain differently linked glycans.
Multiple sugar molecules that may or may...

Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)

Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)

Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...