Acetylene-functionalized lithium initiators for anionic polymerization. Powerful precursors for "click" chemistry

Abstract

Two novel anionic acetylene-functionalized initiators, 5-trimethylsilyl-4- pentynyllithium (TMSPLi) and 5-triethylsilyl-4-pentynyllithium (TESPLi), were synthesized and characterized by 1H NMR, 13C NMR, and GC-MS. TMSPLi was successfully used for the polymerization of styrene, but not for the polymerization of isoprene and butadiene. On the other hand, TESPLi exhibited all characteristics of an anionic initiator for the (co)polymerization of styrene, isoprene, and butadiene. TESPLi is ideal for the synthesis of living well-defined (co)polymers with acetylene end groups, perfect candidates for "click" reactions and at the same time possessing all the potential of living anionic polymerization for the synthesis of well-defined complex macromolecular architectures. © 2011 American Chemical Society.