title: Thiyl radical-mediated cyclization of ω-alkynyl O-tert-butyldiphenylsilyloximes.
abstract: ω-Alkynyl O-tert-butyldiphenylsilyloximes, upon treatment with odorless 4-tert-butylbenzenethiol in the presence of azobisisobutyronitrile (AIBN) in refluxing benzene, underwent addition of a thiyl radical to the alkynyl group followed by radical cyclization of the corresponding vinyl radical onto the O-silyloxime moiety to give cyclic O-silylhydroxylamines in good yields. The reactivity of O-silyloximes in radical cyclization was similar to or even higher than that of O-benzyloximes. Facile removal of the silyl group of the cyclization products leading to hydroxylamines and nitrone formation of the hydroxylamines were also demonstrated.
authors.affiliation: Showa Pharmaceutical University, 3-3165, Higashi-Tamagawagakuen, Machida, Tokyo, Japan. tamura@ac.shoyaku.ac.jp.
authors.forename: Nina
authors.initials: N
authors.lastname: Shibata
authors.affiliation: Showa Pharmaceutical University, 3-3165, Higashi-Tamagawagakuen, Machida, Tokyo, Japan. tamura@ac.shoyaku.ac.jp.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Tsuchiya
authors.affiliation: Showa Pharmaceutical University, 3-3165, Higashi-Tamagawagakuen, Machida, Tokyo, Japan. tamura@ac.shoyaku.ac.jp.
authors.forename: Yoshimitsu
authors.identifier: http://orcid.org/0000-0002-2868-901X
authors.initials: Y
authors.lastname: Hashimoto
authors.affiliation: Showa Pharmaceutical University, 3-3165, Higashi-Tamagawagakuen, Machida, Tokyo, Japan. tamura@ac.shoyaku.ac.jp.
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Morita
authors.affiliation: Showa Pharmaceutical University, 3-3165, Higashi-Tamagawagakuen, Machida, Tokyo, Japan. tamura@ac.shoyaku.ac.jp.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Ban
authors.affiliation: Showa Pharmaceutical University, 3-3165, Higashi-Tamagawagakuen, Machida, Tokyo, Japan. tamura@ac.shoyaku.ac.jp.
authors.forename: Osamu
authors.identifier: http://orcid.org/0000-0002-5415-8378
authors.initials: O
authors.lastname: Tamura