A straightforward and rapid synthesis of polydithioacetals in the presence of chlorodimethylsilane

We focused on the synthesis of polydithioacetals (PDTAs) using chlorodimethylsilane (CDMS). In one of our previous studies, thioacetal formation was observed when CDMS was used to perform the reductive etherification reaction (RER) on a pendant aldehyde polymer platform along with thiols. This result was not surprising since CDMS has both Lewis acid and reducing agent characteristics, yet it was strikingly unexpected. Inspired by this study, PDTA synthesis using CDMS was proposed. Optimization of polymerization conditions was first carried out by comparing traditional acid sources with CDMS. The progress of polymerizations was kinetically monitored, and CDMS was found to perform best. Various parameters, such as the equivalent of reactants, solvent, and polymerization time, were then examined. A library of PDTAs with moderate to high molecular weights was created using a variety of aldehydes and dithiols. A mechanistic approach for the polymerization was proposed, and finally, a model degradation study on a representative PDTA was performed in the presence of hydrogen peroxide.

Rapid synthesis of polydithioacetals (PDTAs) under mild conditions in high yields and varying molecular weights in the presence of chlorodimethylsilane (CDMS) is reported.