Synthesis of Well-Defined Multifunctionalized Polystyrenes with Benzyl Bromide Moieties by a Novel Iterative Divergent Approach

摘要

Well-defined chain-end-functionalized polystyrenes with two, four, eight, sixteen, and thirty-two benzyl bromide moieties were synthesized by the methodology based on a novel iterative divergent approach. In this methodology, the entire iterative synthetic sequence involves only two sets of the reactions: a coupling reaction of the terminal benzyl bromide moieties with the functionalized anion prepared from 1,1-bis(3-tert-butyldimethylsilyloxymethylphenyl)ethylene and sec-BuLi and a transformation reaction of the introduced tert-butyldimethylsilyloxymethyl groups into bromomethyl functions by treatment with LiBr-(CH_3)_3SiCl. The iteration started with chain-end-functionalized polystyrene with one benzyl bromide moiety and could be repeated five times. All iterations proceeded quantitatively to afford chain-end-functionalized polystyrenes with a definite number of benzyl bromide moieties up to thirty-two.