Graft and RAFT Reactive Macro Reagents: Bis-[copoly-(divinyl ether-alt-maleic anhydride)]-trithiocarbonate

The alternating cyclocopolymer of maleic anhydride with divinyl ether (MADVE) hydrolyzate, as mimicker of furan related and anionic residues alternation in nucleic acids (NA) backbone, is immune stimulating agonist and competitive antagonist for viral genome NA interventions. The targeted pre-modification of MADVE by antiviral vectors via grafting to the MA anhydride residues before hydrolysis led to more potent and promising antiviral inhibitors. To develop the MADVE capacity for novel modifications we applied the reversible addition – fragmentation chain transfer (RAFT) technique using dibenzyl trithiocarbonate as a RAFT agent. The insertion of trithiocarbonate unit in polymeric chain provided a pseudo living RAFT-polymerization, resulting in: 1) the effective control of polymerization degree (increased with time and conversion), and 2) the narrow dispersive (PDI = 1.1–1.2) products MADVE-S-CS-S-MADVE yield. These products can be used as novel polymeric RAFT-agents for synthesis of new block-copolymers MADVE-(block)-CS₃-(block)-MADVE, for instance with polystyrene blocks. Combined together the RAFT- and graft- reactivity allows both modify the polymer backbone (RAFT-synthesis) and regulate the side groups or branches (grafted to MADVE moieties) with final hydrolysis of unused anhydride units to acidic polyelectrolyte derivatives. This plural reactive capacity of the obtained macro reagents essentially enhances their potential as platform for purposed synthesis of novel (bio-) functional polymeric compounds.