On Thiol‐Ene Radical Coupling Reaction when Synthesis of ABCL2Type Heteroarm Star Copolymer Containing PDPA Arm

Abstract

AbstractIn this paper, we designed novel ABCL2‐type heteroarm star copolymers, where A, B and C are poly(ϵ‐caprolactone) (PCL), poly(2‐(diisopropylamino) ethyl methacrylate) (PDPA) and poly(2‐methacryloyloxyethyl phosphorylcholine) (PMPC) arms, respectively, and L is 4‐([2,2′:6′,2′′‐terpyridine]‐4′‐yl) phenyl (Tpyp) ligand group. In the final synthesis step, thiol‐ene radical coupling was used to link PMPC chain onto PCL/PDPA copolymer to form a heteroarm star copolymer. However, it was found that the presence of the PDPA block with tertiary amine moieties led the thiol‐ene radical coupling not to be achieved easily in common conditions. Herein we focus on investigating the photoinitiated thiol‐ene coupling reaction. Finally, we achieve the reaction via selecting appropriate solvent. It is expected that the exploration can broaden application of thiol‐ene radical reaction in synthesis of polymer architectures.