Visible Light-Initiated Preparation of Functionalized Polystyrene Monoliths for Flow Chemistry

Styrenic monoliths are produced using a novel visible light-initiated method. Monoliths with varying pore sizes are produced using 1-dodecanol and 1-dodecanol/THF mixtures and it was demonstrated that the more volatile i-PrOH can replace 1-dodecanol while still providing the same porogenic properties. In addition, the visible light-initiation protocol enables the facile incorporation of monomers that are incompatible with thermal or UV-initiated monolith formation methods. In particular, a reactive N-hydroxysuccinimidyl (NHS)-ester can be incorporated into the monolith and then subsequently used as an attachment point for a catalyst. Lastly, we demonstrate that the functionalized monolith supports acylation reactions well and that the loading of the catalyst impacts the reaction rate.