Controlled Ring-Opening Polymerization Of Macrocyclic Monomers Based On The Quinone Methide Elimination Cascade Reaction

A controlled ring-opening polymerization (ROP) of macrocyclic monomers was developed based on the nucleophilic ring-opening mechanism for the first time. This novel ROP was designed to prepare backbone functional and sequence-defined polymers with controlled molecular weights and narrow dispersities (D < 1.1) by polymerizing the macrocycles with a quinone methide elimination-based self-immolative spacer as the "ring-opening trigger". This ROP was initiated by an efficient nucleophilic substitution of activated carbonate with a primary amine to ring open the macrocyclic monomers. The following spontaneous 1,6-elimination-decarboxylation cascade reaction disassembled the self-immolative spacer to regenerate the primary amine end group for subsequent polymer chain propagation. The versatility of this novel ROP was demonstrated by the formation of well-defined water-soluble, backbone-degradable, and sequence-defined polyurethanes and their block copolymers.