Hyperbranched Poly(ester‐enamine) from Spontaneous Amino‐yne Click Reaction for Stabilization of Gold Nanoparticle Catalysts

Abstract

Hyperbranched polymers have attracted much attention due to attractive properties and wide applications, such as drug controlled release, stimuli-responsive nano-objects, photosensitive materials and catalysts. Herein, a novel hyperbranched poly(ester-enamine) (hb-PEEa) was designed and synthesized via the spontaneous amino-yne click reaction of A2 monomer (1, 3-bis(4-piperidyl)-propane or piperazine) and B3 monomer (trimethylolpropanetripropiolate). By controlling monomer concentration, molar ratio and rate of addition, gelation during synthesis can be successfully avoided. The resultant hb-PEEa possesses favorable solubility in various organic solvents. Due to abundant alkynyl groups in termini, the hb-PEEa can be functionalized by different amino compounds or their derivates, which shows desirable potential in stabilization of metal nanoparticles. The amphiphilic PEG-hb-PEEa copolymer can be used as surfactant to stabilize Au nanopaticles (AuNPs) during reduction of NaBH4 in aqueous solution. As a demonstration, the as-prepared PEG-hb-PEEa-supported AuNPs demonstrate good water solubility, high stability and remarkable catalytic activity for reduction of nitrobenzene compounds.

Propiolated Castor Oil: A Novel and Highly Versatile Bio-Based Platform for Extremely Fast, Catalyst-, and Solvent-Free Amino-yne Click Reactions

“…Nevertheless, it was previously shown that alkynes bearing EWGs (activated alkynes) are also suitable Michael acceptors. Indeed, the reaction between an amine and an activated alkyne is named as spontaneous amino-yne click reactions, and these reactions have been successfully adopted for various applications and the synthesis of several polymers known as poly­(enamine)­s. − As the name suggests, spontaneous amino-yne click reactions are straightforward, fast, and occur spontaneously at room temperature.…”

Organobase-catalyzed carboxyl-yne click polymerization

“…[28][29][30][31] It also provides a solution for the synthesis of unsaturated polyester. [32][33][34][35][36][37][38][39] Moreover, the direct addition of carboxylic acid to alkynes is the most economical and widely used method. [40] The enol ester obtained by the addition of alkyne and carboxylic acid has a wide range of applications in organic synthesis, pharmaceutical chemistry and polymer construction.…”