Beyond Stereoselectivity, Switchable Catalysis: Some of the Last Frontier Challenges in Ring‐Opening Polymerization of Cyclic Esters

摘要: Metal-based catalysts and initiators have played a pivotal role in the ring-opening polymerization (ROP) of cyclic esters, thanks to their high activity remarkable ability control precisely architectures resulting polyesters terms molar mass, dispersity, microstructure, or tacticity. Today, after two decades extensive research, field is slowly reaching maturity. However, several challenges remain, while original concepts emerged around new types applications catalysis. This Review not intended comprehensively cover all these aspects. Rather, it provides personal overview very recent progress achieved some selected, important aspects ROP catalysis-stereocontrol switchable Hence, first part addresses development metal-based for isoselective racemic lactide towards stereoblock copolymers, use syndioselective metal monomer sequence copolymers. A second covers catalysts-primarily catalysts, but also organocatalysts-that can be externally regulated by chemical photo stimuli switch them between states with different catalytic abilities. Current opportunities are highlighted.