Ruthenium-Catalyzed C−H/CO/Olefin Coupling Reaction of N-Arylpyrazoles. Extraordinary Reactivity of N-Arylpyrazoles toward Carbonylation at C−H Bonds
journal contributionposted on 26.08.2003, 00:00 by Taku Asaumi, Naoto Chatani, Takuya Matsuo, Fumitoshi Kakiuchi, Shinji Murai
The reaction of 1-arylpyrazoles with CO and ethylene in the presence of Ru3(CO)12 resulted in regioselective carbonylation at the ortho C−H bonds. While it is found that the pyrazole ring also functions as the directing group for C−H bond cleavage, the efficiency of the reaction depends on the position of the pyrazole ring.