Ruthenium-Catalyzed C−H/CO/Olefin Coupling Reaction of <i>N</i>-Arylpyrazoles. Extraordinary Reactivity of <i>N</i>-Arylpyrazoles toward Carbonylation at C−H Bonds

Abstract

The reaction of 1-arylpyrazoles with CO and ethylene in the presence of Ru(3)(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.