Palladium-Catalyzed Oxirane-Opening Reaction with Arenes via C-H Bond Activation.
We achieved a palladium-catalyzed C-H activation/C-C coupling reaction between arenes with a pyridyl, aminoquinolinyl, imino, or amide directing group, and oxiranes. The reaction proceeded at room temperature without any additives and tolerated a wide variety of functional groups, and the products were obtained in good to excellent yields, even on gram scale. This is the first example of a transition-metal-catalyzed intermolecular direct coupling reaction between a C-H bond of aromatic compounds and a carbon atom of oxiranes via C-H bond activation. By using N-methoxybenzamide as a substrate, we obtained 3-substituted isochroman-1-ones in one pot. The coupling reaction proceeded with stereoretention. Kinetic isotope effect experiments suggested that C-H bond activation is the rate-determining step.
†Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.|‡Kanai Life Science Catalysis Project, ERATO (Japan) Science and Technology Agency (JST), 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Zhen
Z
Wang
†Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.|‡Kanai Life Science Catalysis Project, ERATO (Japan) Science and Technology Agency (JST), 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Yoichiro
Y
Kuninobu
†Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.|‡Kanai Life Science Catalysis Project, ERATO (Japan) Science and Technology Agency (JST), 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Motomu
M
Kanai
D002384:Catalysis; D002867:Chromones / Q000138:chemical synthesis / Q000737:chemistry; D005027:Ethylene Oxide / Q000737:chemistry*; D006841:Hydrocarbons, Aromatic / Q000737:chemistry*; D007700:Kinetics; D010165:Palladium / Q000737:chemistry*
D002867:Chromones; D006841:Hydrocarbons, Aromatic; D010165:Palladium; D005027:Ethylene Oxide