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

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.

Automated summary

In this study, a simple one-pot synthesis of α-thiol-ω-hydroxylpolyethers was reported, achieved through ring-opening polymerization (ROP) of epoxides using thiocarboxylic acid initiators followed by in situ aminolysis. The metal-free Lewis pair catalyst utilized in this method allowed for efficient and chemoselective polymerization, resulting in controlled molar mass, low dispersity, and high end-group fidelity. The stability of thioester during the ROP also allowed for the synthesis of α-thiol-ω-dihydroxyl (Y-shaped) PEO, which exhibited enhanced protein resistance behavior due to the intensified interaction with gold surfaces.