Sequence Controlled Polymers from a Novel β-Cyclodextrin Core

In this work the synthesis and use of a novel β-cyclodextrin-based single electron transfer-living radical polymerization (SET-LRP) initiator are reported. Three different approaches toward the synthesis of this initiator, based on several "click"-like reactions (copper(I)-catalyzed azide-alkyne cycloaddition, nucleophilic thiol-ene reaction, and radical thiol-ene reaction), are explored and discussed. Synthesis via radical thiol-ene proves to be most successful in achieving this. The β-cyclodextrin-based initiator is subsequently used for the polymerization of several acrylates in a controlled fashion, yielding 7-arm multiblock copolymers. The achieved sequence-controlled polymers exhibit low dispersities (≤1.12) and are completed under 6.5 h at high monomer conversion (≥95%) for each block.