Modular Synthesis of Polyferrocenylsilane Block Copolymers by Cu-Catalyzed Alkyne/Azide “Click” Reactions

Abstract

This paper reports a new synthetic strategy for the preparation of polyferrocenylsilane (PFS) block copolymers. The block copolymers were prepared by Cu-catalyzed alkyne/azide cycloaddition of two homopolymer precursors that allows access to new functional PFS block copolymers (e.g., polyferrocenylsilane-block-poly(N-isopropylacrylamide)) (PFS-b-PNIPAM)). Trimethylsilyl-protected, alkyne-terminated PFS homopolymer was first prepared via living anionic polymerization, terminating living PFS with commercially available 4-[(trimethylsilyl)ethynyl]benzaldehyde. Subsequent deprotection of the trimethylsilyl group with NaOMe yielded the ethynyl-terminated PFS (ω-alkyne-PFS). This method should be readily applicable to other polymers prepared by living anionic polymerization. Subsequently, non-PFS homopolymers containing a complementary “clickable” azide functional group were synthesized either by anionic polymerization, modification of a commercially available polymer, or atom transfer radical polymerization vi...