BF 3 ·Et 2 O mediated one-step synthesis of N-substituted-1,2-dihydropyridines, indenopyridines and 5,6-dihydroisoquinolines

O mediated novel methodology, from easily available α,β-unsaturated ketones/arylidene ketones, phenyl acetylenes and substituted nitriles, has been described. This novel annulation provides quick access to complex polycyclic frameworks with an excellent substrate scope.