The cobalt-catalyzed desilylative annulation of C(sp2)–H bonds of benzamides and acrylamides with alkynylsilanes assisted by an 8-aminoquinolyl directing group is reported. A variety of benzamides and acrylamides were compatible in this protocol to construct various 3-methyleneisoindolin-1-one and 5-methylene-1H-pyrrol-2(5H)-one derivatives with Z-configuration selectivity in moderate to high yields.