| Abstract: | In this contribution, we explored the catalytic ring‐opening polymerization (ROP) of (macro)lactones using salen–aluminum complexes bearing cyclic β‐ketoiminato ligand. The effects of bridge moiety and ring size in the benzocyclane skeleton on the catalytic activity of these complexes were thoroughly investigated. Complex 5 with 2,2‐dimethylpropylene bridge and five‐membered cyclane ring can efficiently catalyze the ROP of ω‐pentadecalactone (ω‐PDL), showing higher catalytic activity (turnover frequency TOF] up to 309.2 h?1) than the typical Al‐salen analogs bearing salicylaldiminato ligand (TOF = 227.2 h?1). Thus, polyethylene‐like polyester with high‐molecular weight (up to 164.5 kg/mol) could be easily prepared under optimal conditions. In addition, complex 5 can also catalyze the ROP of lactide (LA) and ε‐caprolactone (ε‐CL) with extremely high activity (TOF is high up to 147.6 h?1 and 4752 h?1, respectively). Here, we demonstrated a rare mono‐nuclear salen‐Al complex that can prompt the ROP of (macro)lactones with unprecedentedly high efficiency. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 973–981 |
