Herein, we report Ru(II)-catalyzed C–H/N–H
bond functionalization
of N-chlorobenzamides with 1,3-diynes via regioselective
(4 + 2) annulation for the synthesis of isoquinolones under redox-neutral
conditions at room temperature. This represents the first example
of C–H functionalization of N-chlorobenzamides
using an inexpensive and commercially available [Ru(p-cymene)Cl2]2 catalyst. The reaction is operationally
simple, works in the absence of any silver additives, and is also
applicable to a broad range of substrates with good functional group
tolerance. The synthetic utility of the isoquinolone is demonstrated
for the synthesis of bis-heterocycles consisting of isoquinolone–pyrrole
and isoquinolone–isocoumarin scaffolds.