Copper(0)-Catalyzed One-Pot Synthesis of ABC Triblock Copolymers via the Combination of Single Electron Transfer Nitroxide Radical Coupling Reaction and "Click" Chemistry

The synthesis of ABC triblock copolymers were accomplished by Cu(0)-catalyzed one-pot strategy combining single electron transfer-nitroxide radical coupling (SET-NRC) reaction with "click'' chemistry. First, the precursors a, x-hetero-functionalized poly(ethylene oxide)(PEO) with a 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) group and an alkyne group, polystyrene (PS), and poly(tert-butyl acrylate) (PtBA) with bromine or azide end group were designed and synthesized, respectively. Then, the one-pot coupling reactions between these precursors were carried out in the system of Cu(0)/Me6T-REN: The SET-NRC reaction between bromine group and nitroxide radical group, subsequently click coupling between azide and alkyne group. It was noticeable that Cu(I) generated from Cu(0) by SET mechanism was utilized to catalyze click chemistry. To estimate the effect of Cu(0) on the one-pot reaction, a comparative analysis was performed in presence of different Cu(0) species. The result showed that Cu(0) with more active surface area could accelerate the one-pot reaction significantly. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 2594-2600, 2011