title: Palladium-catalyzed cycloaddition of alkynyl aryl ethers with internal alkynes via selective ortho C-H activation.
abstract: Alkynyl aryl ethers react with internal alkynes through selective ortho C-H activation by a palladium(0) catalyst to give substituted 2-methylidene-2H-chromenes. The alkynoxy group acts as a directing group to promote ortho C-H functionalization. Deuterium-labeling experiments indicated that the arylpalladium hydride complex is a key intermediate via oxidative addition. Various functional groups tolerate the present transformation to give the corresponding products.
authors.affiliation: Research and Development Initiative, Chuo University, Kasuga, Tokyo 112-8551, Japan. yminami@kc.chuo-u.ac.jp
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Minami
authors.forename: Yuki
authors.initials: Y
authors.lastname: Shiraishi
authors.forename: Kotomi
authors.initials: K
authors.lastname: Yamada
authors.forename: Tamejiro
authors.initials: T
authors.lastname: Hiyama