Described herein is a convenient and highly selective synthesis of alkynylated isoquinolines and biisoquinolines from various aryl ketone O-pivaloyloxime derivatives and 1,3-diynes via rhodium-catalyzed C-H bond activation. In this transformations, alkynylated isoquinolines, 3,4'- and 3,3'-biisoquinolines could be obtained respectively through changing the reaction conditions. Mechanistic investigation revealed that the C-H activation of aryl ketone O-pivaloyloxime was the key step to this reaction.