An efficient synthesis of 1,2-dihydroisoquinolines and -quinolines by employing dimethyl acetylenedicarboxylate activated isoquinolines and quinolines in conjuction with the CuCl2/Et3N catalytic system is described herein. Furthermore, the MoO3-catalysed alkynylation of pyridines and substituted pyridines has also been achieved. Moreover, this process has allowed the rapid synthesis of alkynyl derivatives