Synthesis of Riboflavin-Based Macromolecules through Low ppm ATRP in Aqueous Media

A vitamin-B-2-based macroinitiator is prepared by esterification of riboflavin with 2-bromoisobutyryl bromide. Following the core first methodology, phoenix-shape (co)polymers with a polar riboflavin core and either a hydrophobic (poly(n-butyl acrylate) or poly(methyl methacrylate)) or hydrophilic (poly(N-isopropylacrylamide)-block-poly(oligo(ethylene glycol) acrylate) or poly(N-isopropylacrylamide)-block-poly(2-hydroxyethyl acrylate)) tails are synthesized via low ppm atom transfer radical polymerization procedures. Polymers have predetermined molecular weights and a low dispersity ( < 1.2). H-1 NMR analysis confirms the successful formation of targeted (co)polymers with the preserved riboflavin functionality.