ABSTRACT
Molecules containing heterocyclic substructures have always attracted the attention of researchers for their biological activities. Interest in heterocyclic scaffolds containing pyrazole and indazole nucleus has been stimulated because of their properties suited for industrial, agricultural and medicinal purposes. A. Geny et al. studied the effect of N-heterocyclic carbenes on the synthesis of fused polycyclic cyclohexadienes by cyclization of enediyne substrates. H. Ohno et al. synthesized fused heterocyclic systems from allylamines by two sequential palladium-catalyzed Heck cyclizations which occurred through ‘zipper-mode’ double carbon-hydrogen bond activation. The Hammett equation was used to analyze the ratio of products; the results obtained were anticipated to she light on the nature of carbon-nitrogen bond formation. It was observed that the carbon-nitrogen bond formation proceeded through electrophilic aromatic substitution (EAS) and a linear correlation to s meta-constants. The meta-position of methoxy group with respect to the reaction center made it an inductive electron-withdrawing group for EAS.
