Synthesis of naturally-derived macromolecules through simplified electrochemically mediated ATRP.

The flavonoid-based macroinitiator was received for the first time by the transesterification reaction of quercetin with 2-bromoisobutyryl bromide. In accordance with the "grafting from" strategy, a naturally-occurring star-like polymer with a polar 3,3',4',5,6-pentahydroxyflavone core and hydrophobic poly(-butyl acrylate) (PBA) side arms was synthesized via a simplified electrochemically mediated ATRP (ATRP), utilizing only 78 ppm by weight (wt) of a catalytic Cu complex. To demonstrate the possibility of temporal control, ATRP was carried out utilizing a multiple-step potential electrolysis. The rate of the polymerizations was well-controlled by applying optimal potential values during preparative electrolysis to prevent the possibility of intermolecular coupling of the growing polymer arms. This appears to be the first report using on-demand ATRP for the synthesis of QC-(PBA-Br)-star polymers. The naturally-derived macromolecules showed narrow MWDs ( = 1.08-1.11). H NMR spectral results confirm the formation of quercetin-based polymers. These new flavonoid-based polymer materials may find applications as antifouling coatings and drug delivery systems.