A systematic screening study onorthoC-H alkenylation of beta-carbolines with terminal alkynes using different transition metal catalysts is described. The investigation clearly shows that [Ru(p-cymene)Cl-2](2)catalyst is suitable for the C-H alkenylation of beta-carbolines as the substrate as well as directing group. The selective formation of monoalkenylated products was accomplished in good to excellent yields. Various substrates with excellent functional group tolerance for C1-phenyl/thienyl-beta-carbolines and 6,7-dimethoxyisoquinolines was demonstrated. A number of novel alkenylated beta-carbolines (3a-3m) and 6,7-dimethoxy isoquinolines (7a-7h) was achieved in (63-85 %) and (81-89 %) yields respectively. Also, the newly synthesized alkenylated beta-carbolines and isoquinolines were investigated for their anticancer activity.