Bifunctional catalysts,known for their superior activity and selectivity compared to binary systems,hold great promise for ring-opening copolymerization(ROCOP).Here,we present our recent advancements in developing hig...Bifunctional catalysts,known for their superior activity and selectivity compared to binary systems,hold great promise for ring-opening copolymerization(ROCOP).Here,we present our recent advancements in developing high-performance bifunctional organocatalysts by integrating borane with triaminocyclopropenium(TAC)derivatives.Specifically,we developed a bifunctional catalyst by conjugating 9-borabicyclo[3.3.1]nonane(9-BBN)with TAC-Cl through an optimized alkyl linker(TB-3).This catalyst exhibited outstanding performance in the controlled ROCOP of epoxides and anhydrides,demonstrating high activity,selectivity,and thermal stability,and outperforming both binary catalytic systems and quaternary ammonium-borane analogs.Notably,further transformation of the TAC moiety into its cyclopropenimine(CPI)derivative led to the creation of a cyclopropenimine-borane bifunctional organocatalyst(CPI-B).The strong yet dissociative intramolecular N-B coordination between the CPI and BBN units imparted exceptional air stability to CPI-B,effectively addressing the challenging issue of air sensitivity commonly associated with conventional organoborane catalysts.Additionally,the N/B Lewis pair in CPI-B effectively activated protic initiators,enabling precise control over end-group functionality and polymer topology in ROCOP.These advancements significantly broaden the practical utility of CPI-B in polymer synthesis.展开更多
基金the financial support from the National Key R&D Program of China(grant no.2021YFA1501600)the Natural Science Foundation of Guangdong Province,China(grant nos.2023A1515011561 and 2025A1515010778)the National Natural Science Foundation of China(grant no.22473047).
文摘Bifunctional catalysts,known for their superior activity and selectivity compared to binary systems,hold great promise for ring-opening copolymerization(ROCOP).Here,we present our recent advancements in developing high-performance bifunctional organocatalysts by integrating borane with triaminocyclopropenium(TAC)derivatives.Specifically,we developed a bifunctional catalyst by conjugating 9-borabicyclo[3.3.1]nonane(9-BBN)with TAC-Cl through an optimized alkyl linker(TB-3).This catalyst exhibited outstanding performance in the controlled ROCOP of epoxides and anhydrides,demonstrating high activity,selectivity,and thermal stability,and outperforming both binary catalytic systems and quaternary ammonium-borane analogs.Notably,further transformation of the TAC moiety into its cyclopropenimine(CPI)derivative led to the creation of a cyclopropenimine-borane bifunctional organocatalyst(CPI-B).The strong yet dissociative intramolecular N-B coordination between the CPI and BBN units imparted exceptional air stability to CPI-B,effectively addressing the challenging issue of air sensitivity commonly associated with conventional organoborane catalysts.Additionally,the N/B Lewis pair in CPI-B effectively activated protic initiators,enabling precise control over end-group functionality and polymer topology in ROCOP.These advancements significantly broaden the practical utility of CPI-B in polymer synthesis.
