摘要
Auto-tandem catalysis that uses a single catalyst to bridge and discriminate different catalytic cycles in a one-pot process is highly desirable for obtaining a high degree of structural complexity;however,it is a great challenge to develop auto-tandem catalytic systems in polymer chemistry.Herein,we report the auto-tandem catalysis by rationally designed aluminum porphyrin complexes,wherein well-controlled photoinduced electron/energy transfer–reversible addition-fragmentation chain transfer(PET-RAFT)polymerization of vinyl monomers and completely alternating ring-opening copolymerization(ROCOP)of epoxides/anhydrides can occur in a concurrent or sequential manner.With a carboxylic group incorporated trithiocarbonate compound bearing a carboxylic acid group(TTC-COOH)as the bifunctional chain transfer agent(CTA),the auto-tandem catalysis provides one-pot access to diblock copolymers with predictable molecular weights and narrow distributions.Notably,the efficient electron/energy transfer from 5,10,15,20-tetrakis(2-chlorophenyl)porphyrin aluminum(III)chloride[(TPP^(2-Cl))Al^(III)-Cl]to TTC-COOH and their axial group exchange reactions completely circumvent the formations of undesirable homopolymers.
基金
Financial support from National Key R&D Plan(no.2016YFB0302400)
NSFC(no.21604027)of China
the Fundamental Research Funds for the Central Universities(HUST:2019JYCXJJ015).
