title: Metal-Free Approach to Biaryls from Phenols and Aryl Sulfoxides by Temporarily Sulfur-Tethered Regioselective C-H/C-H Coupling.
abstract: We have developed metal-free regiocontrolled dehydrogenative C-H/C-H cross-coupling of aryl sulfoxides with phenols by means of trifluoroacetic anhydride. Because the reaction would proceed through an interrupted Pummerer reaction followed by sulfonium-tethered [3,3]-sigmatropic rearrangement, the C-H/C-H coupling takes place exclusively between the ortho positions of both substrates. Various functional groups including carbonyl, halo, siloxy, and even boryl moieties are compatible. The biaryl products naturally possess hydroxy and sulfanyl groups, which allows the products to be useful synthetic intermediates, as evidenced by the syntheses of π-expanded heteroarenes such as unprecedented 7,12-dioxa[8]helicene.
authors: Department of Chemistry, Graduate School of Science, Kyoto University , Sakyo-ku, Kyoto 606-8502, Japan.
authors: Tomoyuki
authors: T
authors: Yanagi
authors: Department of Chemistry, Graduate School of Science, Kyoto University , Sakyo-ku, Kyoto 606-8502, Japan.
authors: Shinya
authors: S
authors: Otsuka
authors: Department of Chemistry, Graduate School of Science, Kyoto University , Sakyo-ku, Kyoto 606-8502, Japan.
authors: Yuko
authors: Y
authors: Kasuga
authors: Department of Chemistry, Graduate School of Science, Kyoto University , Sakyo-ku, Kyoto 606-8502, Japan.
authors: Keisuke
authors: K
authors: Fujimoto
authors: Department of Chemistry, Graduate School of Science, Kyoto University , Sakyo-ku, Kyoto 606-8502, Japan.
authors: Kei
authors: K
authors: Murakami
authors: Department of Chemistry, Graduate School of Science, Kyoto University , Sakyo-ku, Kyoto 606-8502, Japan.
authors: Keisuke
authors: K
authors: Nogi
authors: Department of Chemistry, Graduate School of Science, Kyoto University , Sakyo-ku, Kyoto 606-8502, Japan.
authors: Hideki
authors: H
authors: Yorimitsu
authors: Department of Chemistry, Graduate School of Science, Kyoto University , Sakyo-ku, Kyoto 606-8502, Japan.
authors: Atsuhiro
authors: A
authors: Osuka