Borinane Boosted Bifunctional Organocatalysts for Ultrafast Ring-Opening Polymerization of Cyclic Ethers

The design of reactive species that can either serve to initiate the ring-opening polymerization of epoxides for the synthesis of high molar mass polyethers or be alternatively used to catalyze the synthesis of polyether telechelics in the presence of chain transfer agents has long been an elusive goal. Here, we report the synthesis of a series of bifunctional borinane-based catalysts that enable the living ring-opening polymerization of epoxides with an unprecedented activity (TOF ≥ 1.8 × 105 h–1) and a molar mass up to 106 g/mol under mild conditions. When used along with chain transfer agents to generate low Mn telechelics, the same borinane-based catalysts exhibit high productivity even for loading amounts as low as 50 ppb for ethylene oxide polymerization. These newly designed catalysts also afford the polymerization of oxetane with record TOF values and molar masses.