Related Experiment Video
Updated: Apr 19, 2026

Synthesis of Monodisperse Cylindrical Nanoparticles via Crystallization-driven Self-assembly of Biodegradable Block Copolymers
Published on: June 20, 2019
Ring-opening homo- and co-polymerization of lactides and ε-caprolactone by salalen aluminum complexes
Alessia Pilone1, Nicolina De Maio, Konstantin Press
1Dipartimento di Chimica e Biologia, Università di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, Italy. mlamberti@unisa.it.
Abstract:
Aluminum complexes of non-chiral-salalen ligands were investigated in the catalysis of ring-opening polymerization (ROP) of lactide and ε-caprolactone and in their copolymerization. The aluminum-salalen complexes were found to polymerize all varieties of lactide, namely: l-, d-, rac- and meso-lactide, and showed moderate productivities. rac-LA gave rise to isotactic polylactides (with Pm up to 72%), while meso-LA gave rise to heterotactic polylactides (with a Pm of 79%). An experiment was designed for distinguishing between chain-end control and enantiomorphic-site control combined with polymeryl exchange for the isotactic stereoblock microstructure observed for the PLA produced from rac-LA; it gave strong evidence for polymeryl exchange between propagating species. Finally, this class of catalysts promoted the copolymerization of ε-caprolactone and lactides. In particular, compound allowed controlled random copolymerization of ε-caprolactone and l-lactide.
More Related Videos
10:17Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
05:48Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes
Published on: November 21, 2017
Related Concept Videos
Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
Crossed Aldol Reaction Using Strong Bases: Directed Aldol Reaction
Alkylation of β-Diester Enolates: Malonic Ester Synthesis
Dehydration of Aldols to Enals: Base-Catalyzed Aldol Condensation
Aldol Condensation vs Claisen Condensation
Acid-Catalyzed α-Halogenation of Aldehydes and Ketones
In the first step of the mechanism, the acid protonates the carbonyl oxygen resulting in a resonance-stabilized cation, which subsequently loses an α-hydrogen to form an enol tautomer. The C=C bond in an enol is highly nucleophilic because of the electron-donating nature of the –OH group. Consequently, the double bond attacks an electrophilic...