Chemoselectivity Streamlines the Approach to Linear and Y-Shaped Thiol-Polyethers Starting from Thiocarboxylic Acids

作者：Liu, Lijun; Zhao, Junpeng^*; Zhang, Guangzhao

来源：ACS Macro Letters, 2023, 12(9): 1185-1192.

DOI：10.1021/acsmacrolett.3c00407

• RING-OPENING POLYMERIZATION
• ORGANIC SULFUR-COMPOUNDS
• POLY(ETHYLENE GLYCOL)
• POLYETHYLENE-GLYCOL
• PROPYLENE-OXIDE
• ETHYLENE-OXIDE
• BASIS-SET
• IN-SITU
• EPOXIDES
• DISULFIDES

Thiol-functionalized polyethers, especially poly(ethyleneoxide)(PEO), have extensive applications in biomedicine and materials sciences.Herein, we report a simple one-pot synthesis of & alpha;-thiol-& omega;-hydroxylpolyethers through ring-opening polymerization (ROP) of epoxides usingthiocarboxylic acid initiators followed by in situ aminolysis. Theefficient and chemoselective metal-free Lewis pair catalyst avoidstransthioesterification thus achieving well-controlled molar mass,low dispersity, and high end-group fidelity. Kinetic and calculationresults demonstrated a fast-initiation mode of the ROP for the strongnucleophilicity of the thiocarboxylate anion and its weak interactionwith Lewis acid. The method is expanded for & alpha;-thiol-& omega;-dihydroxyl(Y-shaped) PEO by virtue of the stability of thioester during theROP. The thiol functionality in linear/Y-shaped PEO is further corroboratedby the intensified interaction with gold surface and the resultantprotein resistance behavior.