Ruthenium-catalyzed C(sp2)−H ortho-heteroarylation of phthalazin-1(2H)-one using thiophenes by cross-dehydrogenative coupling

Abstract

The cross-dehydrogenative coupling reactions gained supreme importance owing to their synthetic efficiency in accessing simple to complex organic molecules. Herein, we report a Ru(II)-catalyzed directing group-assisted CDC reaction between phthalazin-1(2H)-one and thiophenes. This methodology offers advantages such as excellent regioselectivity with good functional group compatibility resulting in a broad substrate scope. Mechanistically, Ru(II)-catalyzed ortho C(sp2)−H cross-coupling operates via concerted metalation-deprotonation (CMD) mechanism.