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Ring‐Expanding Metathesis Oligomerization of Cyclic Nitrones
Author(s) -
Imada Yasushi,
Okita Chiaki,
Maeda Hiroki,
Kishimoto Masayuki,
Sugano Yoshinori,
Kaneshiro Hiroyuki,
Nishida Yuri,
Kawamorita Soichiro,
Komiya Naruyoshi,
Naota Takeshi
Publication year - 2014
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201402859
Subject(s) - chemistry , ring size , ring (chemistry) , metathesis , nitrone , cyclic peptide , stereochemistry , salt metathesis reaction , cycloaddition , organic chemistry , polymerization , catalysis , polymer , peptide , biochemistry
Although there has been marked progress in the chemistry of five‐ and six‐membered cyclic nitrones, medium‐ and large‐sized cyclic nitrones have remained untouched despite their potential as functional materials. Herein, we report that medium‐sized cyclic nitrones undergo ring‐expanding dimerization/oligomerization in the presence of organic or inorganic acids, and we have successfully characterized a series of novel macrocyclic polynitrones up to a 50‐membered ring size. An unprecedented ring‐size‐dependent specificity was observed for this reaction, in which cyclic nitrones with odd‐number‐membered rings are converted into dimers with high selectivity, whereas even‐number‐membered rings undergo consecutive ring‐expansion reactions to afford macrocyclic polynitrones.