title: Iron-catalyzed C-H bond activation for the ortho-arylation of aryl pyridines and imines with Grignard reagents.
abstract: Direct arylation of the ortho-C-H bond of an aryl pyridine or an aryl imine with an aryl Grignard reagent has been achieved by using an iron-diamine catalyst and a dichloroalkane as an oxidant in a short reaction time (e.g., 5 min) under mild conditions (0 °C). The use of an aromatic co-solvent, such as chlorobenzene and benzene, and slow addition of the Grignard reagent are essential for the high efficiency of the reaction. The present arylation reaction has distinct merits over the previously developed reaction that used an arylzinc reagent, such as its reaction rate and atom economy. Selective C-H bond activation occurs in the presence of a leaving group, such as a tosyloxy, chloro, and bromo group. Studies on a stoichiometric reaction and kinetic isotope effects shed light on the reaction intermediate and the C-H bond-activation step.
authors: Department of Chemistry, School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
authors: Naohiko
authors: N
authors: Yoshikai
authors: Sobi
authors: S
authors: Asako
authors: Takeshi
authors: T
authors: Yamakawa
authors: Laurean
authors: L
authors: Ilies
authors: Eiichi
authors: E
authors: Nakamura