Kinetic principles of living anionic polymerization of isocyanates for constructing complex primary structures in helical polyisocyanates

Living anionic polymerization of isocyanates enabled the synthesis of well‐defined helical polyisocyanates. However, its potential to generate complex primary structures remained largely unexplored. The possibility that polyisocyanates could serve as artificial models of protein conformational transitions motivated me to examine the fundamental kinetic principles of the living anionic polymerization of isocyanates. This Personal Account describes how this motivation led to the elucidation of the origin of livingness, the establishment of a general rate law, and the determination of the monomer structure–reactivity relationship that governs sequence formation. On the basis of this kinetic framework, the selection of appropriate monomer combinations produced block, tapered‐block, and gradient monomer sequence distributions. Sequential living copolymerization integrated these distributions into higher‐order sequence organizations. These studies established polymerization kinetics as a basis for the systematic expansion of the diversity and complexity of primary structures in synthetic helical polymers. This Personal Account further presents my perspective on the contributions of these studies to the field of synthetic helical polymers. It also discusses the challenges and prospects for the use of helical polyisocyanates as artificial models to investigate unresolved biological phenomena associated with protein misfolding, conformational transitions, and amyloid formation.