Controlled-Radical Polymerization of α‑Lipoic Acid: A General Route to Degradable Vinyl Copolymers

• Published in: Journal of the American Chemical Society 2023-10, Vol.145 (41), p.22728-22734
• Main Authors: Albanese, Kaitlin R., Morris, Parker T., Read de Alaniz, Javier, Bates, Christopher M., Hawker, Craig J.
• Format: Article
• Language: English
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.3c08248

Here, we present the synthesis and characterization of statistical and block copolymers containing α-lipoic acid (LA) using reversible addition–fragmentation chain-transfer (RAFT) polymerization. LA, a readily available nutritional supplement, undergoes efficient radical ring-opening copolymerization with vinyl monomers in a controlled manner with predictable molecular weights and low molar-mass dispersities. Because lipoic acid diads present in the resulting copolymers include disulfide bonds, these materials efficiently and rapidly degrade when exposed to mild reducing agents such as tris­(2-carboxyethyl)­phosphine (M n = 56 → 3.6 kg mol–1). This scalable and versatile polymerization method affords a facile way to synthesize degradable polymers with controlled architectures, molecular weights, and molar-mass dispersities from α-lipoic acid, a commercially available and renewable monomer.