Intramolecular Hydrogen‐Bonding Catalyst/Initiator for Precise Synthesis of Polycarbonates and Copolymers with Unprecedented Activity and Molecular Weights

Abstract The development of efficient and selective catalytic methods for synthesizing well‐defined polycarbonates and their copolymers represents a significant advancement toward sustainable polymer production. In this study, we report a series of innovative single‐molecule hydrogen‐bonding catalysts/initiators for the ring‐opening polymerization (ROP) of cyclic carbonates, enabling rapid and precise synthesis of polycarbonates and their copolymers with polylactide. These catalysts uniquely facilitate simultaneous activation of both monomer and chain‐end within a single molecular architecture, demonstrating superior activity compared to conventional multicomponent hydrogen‐bonding initiating systems. Density functional theory (DFT) calculations reveal that alkyl substitution plays a critical role in enhancing catalytic activity for ROP by reducing the energy barrier relative to aryl‐substituted analogues. The modular design of these catalysts allows for facile structural optimization and performance tuning. Notably, Cat. 1 exhibits high catalytic efficiency at 25 °C, producing polycarbonates with well‐defined structures and high molecular weights ( M n up to 164.8 kDa, Ð of 1.37). We further demonstrate versatile copolymerization strategies: one‐step copolymerization yields gradient polycarbonate‐ g ‐polylactide copolymers, whereas sequential monomer addition in one‐pot reactions produces well‐defined block polycarbonate‐ b ‐polylactide copolymers within minutes. These block copolymers exhibit high molecular weights ( M n up to 189.4 kDa, Ð of 1.37), precisely tunable thermal properties, and exceptional mechanical performance, highlighting their potential for advanced material applications.