Ruthenium-catalyzed C(sp2)–H ortho-heteroarylation of 2-arylphthalazin-1(2H)-one using five-membered heteroarenes by cross-dehydrogenative coupling

Abstract

The cross-dehydrogenative coupling reactions have 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 2-arylphthalazin-1(2H)-one and heteroarenes. This methodology offers advantages such as excellent regio-selectivity with good functional group compatibility, resulting in a broad substrate scope. Mechanistically, Ru(II)-catalyzed ortho-C(sp²)–H cross-coupling operates via a concerted metalation–deprotonation (CMD) mechanism.