Photocatalytic unactivated aliphatic C–H bonds azidation: A versatile platform for functionalization of commodity polymers

Abstract

Development of efficient and robust approaches for functionalization of commodity polymers is of significant importance for endowing high-volume and low-cost commodity polymers with new functionalities and application fields. Herein, we report a general strategy to introduce azide units into commodity polymers, such as poly(ethylene glycol), polystyrene, polypropylene and polybutylene, via photocatalytic azidation of unactivated aliphatic C–H bonds using aridinium photoredox catalyst under blue LED irradiation (455 nm, 4 W). The contents of introduced azide units into commodity polymers can be regulated by reaction time. By copper-catalyzed azide-alkyne cycloaddition reaction, the obtained azide-containing commodity polymers can be efficiently modified with desired functional moieties. The azide-containing commodity polymers also can be used to covalently modify carbon-materials (e.g. fullerene) to prepare polymer/carbon-materials composites via azide-ene reaction. Additionally, the introduced azide units can be transformed into amino groups for further functionalization. Given the versatility and robustness of C–H azidation strategy, this work opens a new avenue to generate various functional materials from commodity polymers.