Combining Atom Transfer Radical Polymerization and Click Chemistry: A Versatile Method for the Preparation of End‐Functional Polymers

Abstract Summary: The bromine chain ends of well‐defined polystyrene ( $\overline M _{\rm n}$ = 2 700 g · mol −1 , $\overline M _{\rm w} /\overline M _{\rm n}$ = 1.11) prepared using ATRP were successfully transformed into various functional end groups ( ω ‐hydroxy, ω ‐carboxyl and ω ‐methyl‐vinyl) by a two‐step pathway: (1) substitution of the bromine terminal atom by an azide function and (2) 1,3‐dipolar cycloaddition of the terminal azide and functional alkynes (propargyl alcohol, propiolic acid and 2‐methyl‐1‐buten‐3‐yne). The “click” cycloaddition was catalyzed efficiently by the system copper bromide/4,4′‐di‐(5‐nonyl)‐2,2′‐bipyridine. In all cases, 1 H NMR spectra indicated quantitative transformation of the chain ends of polystyrene into the desired function. Preparation of well‐defined functional polymers possessing diverse chain‐end functionalities by the combination of atom transfer radical polymerization and click chemistry. image Preparation of well‐defined functional polymers possessing diverse chain‐end functionalities by the combination of atom transfer radical polymerization and click chemistry.