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Efficient Heterodifunctional Unimolecular Ring‐Closure Method for Cyclic Polymers by Combining RAFT and SuFEx Click Reactions
Author(s) -
Liu Wenying,
Zhang Shuxiang,
Liu Shengjie,
Wu Zhaoqiang,
Chen Hong
Publication year - 2019
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.201900310
Subject(s) - raft , chain transfer , polymer chemistry , polymerization , monomer , reversible addition−fragmentation chain transfer polymerization , chemistry , polymer , click chemistry , vinyl ether , radical polymerization , organic chemistry
A novel ring‐closure strategy for cyclic polymers by combining reversible addition–fragmentation chain transfer polymerization (RAFT) and the sulfur(VI)‐fluoride exchange (SuFEx) click reaction is presented. Herein, a new heterodifunctional trithiocarbonate RAFT agent, 2‐((tert‐butyldimethylsilyl)oxy)ethyl (4‐(fluorosulfonyl)benzyl) carbonotrithioate (TBDMS‐FSBCT), containing both tert ‐butyldimethylsilyl ether and sulfonyl fluoride moieties, is developed. The polymerization behavior of TBDMS‐FSBCT is first demonstrated by a standard RAFT polymerization procedure for two types of vinyl monomers, N ‐isopropylacrylamide (NIPAAm) (conjugated vinyl monomer) and N ‐vinylpyrrolidone (NVP) (unconjugated vinyl monomer). The tert ‐butyldimethylsilyl ether and sulfonyl fluoride groups at the α and ω positions of the obtained linear polymer precursors (L‐PNIPAAm and L‐PVP) are verified by 1 H, 13 C, and 19 F NMR spectra. Subsequent intramolecular SuFEx click cyclization of the α,ω‐heterofunctionalized linear precursors in air at room temperature conveniently yields the corresponding cyclic polymers (C‐PNIPAAm and C‐PVP). Overall, this is the first report on the preparation of cyclic polymers based on the SuFEx reaction under ambient conditions. It is envisioned that the approach may open an avenue for the formation of cyclic polymers.