Nickel-catalyzed Suzuki-Miyaura reaction of aryl fluorides.
Two protocols for the nickel-catalyzed cross-coupling of aryl fluorides with aryl boronic esters have been developed. The first employs metal fluoride cocatalysts, such as ZrF(4) and TiF(4), which enable Suzuki-Miyaura reactions of aryl fluorides bearing electron-withdrawing (ketones, esters, and CF(3)), aryl and alkenyl groups as well as those comprising fused aromatic rings, such as fluoronaphthalenes and fluoroquinolines. The second protocol employs aryl fluorides bearing ortho-directing groups, which facilitate the difficult C-F bond activation process via cyclometalation. N-heterocycles, such as pyridines, quinolines, pyrazoles, and oxazolines, can successfully promote cross-coupling with an array of organoboronic esters. A study into the substituent effects with respect to both coupling components has provided fundamental insights into the mechanism of the nickel-catalyzed cross-coupling of aryl fluorides.
Center for Atomic and Molecular Technologies, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan. tobisu@chem.eng.osaka-u.ac.jp
Mamoru
M
Tobisu
Tian
T
Xu
Toshiaki
T
Shimasaki
Naoto
N
Chatani