Access to Multiblock Copolymers via Supramolecular Host–Guest Chemistry and Photochemical Ligation

We combine supramolecular host?guest interactions of ?-cyclodextrin (CD) with light-induced Diels?Alder reactions of 2-methoxy-6-methylbenzaldehyde (photoenol, PE) for the formation of multiblock copolymers. Via the synthesis of a new bifunctional chain transfer agent (CTA) and subsequent reversible addition?fragmentation chain transfer (RAFT) polymerization, we introduce a supramolecular recognition unit (tert-butyl phenyl) and a photoactive unit (photoenol) to a polymer chain in order to obtain an α,?-functionalized polymeric center block, having orthogonal recognition units at each chain end. Multiblock copolymers are formed via the light-induced reaction of the photoenol with a maleimide-functionalized polymer chain and the supramolecular self-assembly of the tert-butyl phenyl group with the ?-CD end group of a third polymer chain. By employing the fast and efficient photoinduced Diels?Alder reaction in combination with supramolecular host?guest interactions, a novel method for macromolecular modular ligation is introduced