We have investigated two alternative mechanisms for the ring-opening polymerization of l-lactide using a guanidine-based catalyst, the first involving acetyl transfer to the catalyst, and the second involving only hydrogen bonding to the catalyst. Using computational chemistry methods, we show that the hydrogen bonding pathway is considerably preferred over the acetyl transfer pathway and that this is consistent with experimental information.

Download full-text PDF

Source
http://dx.doi.org/10.1021/ja0764411DOI Listing

Publication Analysis

Top Keywords

ring-opening polymerization
8
polymerization l-lactide
8
l-lactide guanidine-based
8
guanidine-based catalyst
8
acetyl transfer
8
hydrogen bonding
8
reaction mechanism
4
mechanism organocatalytic
4
organocatalytic ring-opening
4
catalyst
4

Similar Publications

Cholesterol-terminated cationic lipidated oligomers (CLOs) as a new class of antifungals.

J Mater Chem B

January 2025

Drug Delivery, Disposition, and Dynamics Theme, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Pde, Parkville, VIC, 3052, Australia.

Infections caused by fungal pathogens are a global health problem, and have created an urgent need for new antimicrobial strategies. This report details the synthesis of lipidated 2-vinyl-4,4-dimethyl-5-oxazolone (VDM) oligomers an optimized Cu(0)-mediated reversible-deactivation radical polymerization (RDRP) approach. Cholesterol-Br was used as an initiator to synthesize a library of oligo-VDM (degree of polymerisation = 5, 10, 15, 20, and 25), with an α-terminal cholesterol group.

View Article and Find Full Text PDF

Fabrication of a micropatterned shape-memory polymer patch with L-DOPA for tendon regeneration.

Biomater Sci

January 2025

Department of Nanobiomedical Science & BK21 FOUR micropatterned shape-memory NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan 31116, Republic of Korea.

A scaffold design for tendon regeneration has been proposed, which mimics the microstructural features of tendons and provides appropriate mechanical properties. We synthesized a temperature-triggered shape-memory polymer (SMP) using the ring-opening polymerization of polycaprolactone (PCL) with polyethylene glycol (PEG) as a macroinitiator. We fabricated a micropatterned patch using SMP capillary force lithography, which mimicked a native tendon, for providing physical cues and guiding effects.

View Article and Find Full Text PDF

Layered transition metal oxides (LTMOs) are attractive cathode candidates for rechargeable secondary batteries because of their high theoretical capacity. Unfortunately, LTMOs suffer from severe capacity attenuation, voltage decay, and sluggish kinetics, resulting from irreversible lattice oxygen evolution and unstable cathode-electrolyte interface. Besides, LTMOs accumulate surface residual alkali species, like hydroxides and carbonates, during synthesis, limiting their practical application.

View Article and Find Full Text PDF

Monomer Design Enables Mechanistic Mapping of Anionic Ring-Opening Polymerization of Aromatic Thionolactones.

Angew Chem Int Ed Engl

January 2025

University of Science and Technology of China, Hefei National Research Center for Physical Sciences at the Microscale, Department of Chemistry, and Polymer Science and Engineering, 96 Jinzhai Road, 230026, Hefei, CHINA.

Degradable chalcogenide polyesters, e.g., polythioesters (PTEs), typically exhibit improved thermal, mechanical, and optical properties.

View Article and Find Full Text PDF

Polyethers are versatile materials extensively used in advanced as well as everyday applications. The incorporation of primary amine functionality into polyethers is particularly attractive due to its well-established coupling chemistries. However, the inherent nucleophilicity of amine group poses a challenge in the anionic ring-opening polymerization (ROP) of epoxides and requires the use of robust protecting groups that can withstand the harsh conditions of ROP without triggering undesirable side reactions.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!