title: Annulation of Alkynyl Aryl Ethers with Allyl Pivalates To Give 2,3-Bismethylenechromanes through Double C-H Bond Cleavage.
abstract: The treatment of silylethynyloxyarenes with allylic pivalates in the presence of a palladium catalyst led to efficient C-H bond cleavage in both substrates and a novel annulation reaction to give 2,3-bismethylenechromanes. When ortho-allylated silylethynyloxybenzenes were used as the substrates, the same products were obtained. This result shows that site-selective intramolecular hydrovinylation is involved in the annulation reaction. The synthetic utility of the products was demonstrated by the construction of condensed polycycles.
authors.affiliation: Research and Development Initiative, Chuo University, Kasuga, Bunkyo-ku, Tokyo, 112-8551, Japan. yminami@kc.chuo-u.ac.jp.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Minami
authors.affiliation: Department of Applied Chemistry, Chuo University, Kasuga, Bunkyo-ku, Tokyo, 112-8551, Japan.
authors.forename: Megumi
authors.initials: M
authors.lastname: Sakai
authors.affiliation: Department of Applied Chemistry, Chuo University, Kasuga, Bunkyo-ku, Tokyo, 112-8551, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Anami
authors.affiliation: Research and Development Initiative, Chuo University, Kasuga, Bunkyo-ku, Tokyo, 112-8551, Japan. thiyama@kc.chuo-u.ac.jp.
authors.forename: Tamejiro
authors.initials: T
authors.lastname: Hiyama
keywords: C−C coupling; C−H activation; alkynes; allyl substrates; annulation