Synthesis of inositol‐based star polymers through low ppm ATRP methods

Abstract

The vitamin B8‐based macroinitiator with six 2‐bromoisobutyric initiating sites was prepared for the first time by the transesterification reaction of meso‐inositol with 2‐bromoisobutyryl bromide. A series of six‐armed (co)polymers, containing hydrophilic poly(di(ethylene glycol) methyl ether methacrylate) and amphiphilic poly(di(ethylene glycol) methyl ether methacrylate)‐block‐poly(methyl methacrylate) as the arms and meso‐inositol as the core, were obtained by low ppm atom transfer radical polymerization (ATRP) methods, utilizing 30 ppm of catalyst complex. Under Fe0‐mediated supplemental activators and reducing agents ATRP, Cu0‐mediated supplemental activators and reducing agents ATRP, Ag0‐mediated activators regenerated by electron transfer ATRP, and simplified electrochemically mediated ATRP conditions, polymerization proceeded on to high conversion while maintaining low dispersity (Đ = 1.05–1.16) giving well‐defined six‐armed star (co)polymers. 1H NMR spectral results confirm the formation of new star‐shaped block (co)polymers. The absence of intermolecular coupling reactions during synthesis was confirmed by gel permeation chromatography analyses of the side chains of received star (co)polymers. These vitamin B8‐based star (co)polymers may find biomedical applications as thermo‐sensitive drug delivery systems, biosensors, and tissue engineering solutions. Copyright © 2017 John Wiley & Sons, Ltd.

Synthesis of Riboflavin‐Based Macromolecules through Low ppm ATRP in Aqueous Media

“…Significant progress has been recently achieved allowing to diminish the concentration of Cu‐based catalysts to parts per million (ppm) due to an application of additional activator regeneration redox step. It can be triggered by the introduction of a reducing compound, for example, radical initiator in initiators for continuous activator regeneration (ICAR) ATRP, chemical reducing agents (e.g., glucose, ascorbic acid, hydrazine), and metallic silver in activators regenerated by electron transfer (ARGET) ATRP, zerovalent metals (Fe 0 , Cu 0 ) in supplemental activator and reducing agent (SARA) ATRP. Alternatively, an external stimuli such as a reducing current in electrochemically mediated ATRP ( e ATRP) and simplified electrochemically mediated ATRP ( se ATRP), light in photo‐induced ATRP (photo‐ATRP), or mechanical forces in mechanically induced ATRP (mechano‐ATRP) and in ultrasonication‐induced ATRP (sono‐ATRP) can be applied .…”

“…One of the most useful ATRP synthetic methods to prepare polymers with complex architecture is grafting‐from. This procedure includes two simple steps: preparation of functional macroinitiator by the incorporation of brominated initiation sites and polymerization of wide range of monomer to prepare graft macromolecules …”

“…www.advancedsciencenews.com www.mcp-journal.de sites and polymerization of wide range of monomer to prepare graft macromolecules. [24,47] The article presents the preparation of riboflavin-based ATRP initiator and its application in the synthesis of polyacryalmides and poly(meth)acrylates. Up to now, riboflavin was used only once in RDRP.…”

Preparation of hydrophobic tannins‐inspired polymer materials via low‐ppm ATRP methods

“…In the case of complex architecture, ATRP is favorable due to control of polymer topology and site‐specific incorporation of functionalities . The alternative to classical ATRP approach is the variation of this method characterized by diminished catalyst concentration . The reduction of catalyst complex amount is based on its continuous regeneration due to incorporation of an additional redox cycle using an appropriate reducing agent or external stimulus .…”

“…The reduction of catalyst complex amount is based on its continuous regeneration due to incorporation of an additional redox cycle using an appropriate reducing agent or external stimulus . These techniques include, among others, supplemental activator and reducing agent (SARA) ATRP utilizing metallic copper as a reducing agent, activator regeneration by electron transfer (ARGET) ATRP using elemental silver to effective reduction of the catalyst complex in the higher oxidation state, what also limits side reactions, and hence by‐products, moving to a more environmentally friendly method using an external stimulus to receive activators—simplified electrochemically mediated ATRP ( se ATRP), which uses an electric current without the necessity of introducing any additional chemical compound making this technique extremely pure in context to the current state of art …”