Synthetic approaches that harness metal-catalyzed pathways can provide facile alternatives to cumbersome conventional strategies. The dissertation reports advances made towards exploring novel catalytic processes and substrates for the formation of C–C (C–H activation, Suzuki-coupling), C–B (borylation) and C–N (amination) bonds. In order to improve the sustainability of the processes investigated, a conscious effort was made to move from precious metal- (palladium, iridium) catalyzed reactions towards the use of more earth abundant metals (cobalt, iron), with promising results. The sterically governed, iridium-catalyzed regioselective borylation of a novel class of substituted biaryls has been achieved. The biaryl pinacol esters obtained, have been demonstrated as enabling motifs for building C–O, C–Br and C–C bonds. The one-pot combination of a palladium-catalyzed Suzuki-Miyaura cross-coupling and a Buchwald-Hartwig amination has been employed to afford a series of substituted carbazoles. The protocol, using ortho-chloroboronic acids and ortho-bromoanilines, relies on readily available starting materials and mild conditions, whilst avoiding the formation of any isomers. The versatility of the reaction is demonstrated by the selective substitution at various points of the carbazole ring. An efficient synthetic route has been proposed for substituted cyclohexa-m-phenylenes, based on palladium- and iridium-catalyzed reactions leading to the functionalized terphenyls. These terphenyl synthons when reacted under Suzuki-Miyaura crosscoupling conditions, cyclise to cyclohexa-m-phenylenes. Cobalt has been shown as a promising alternative to palladium for the Suzuki-Miyaura cross-coupling of aryl halides. The developed protocol shows how readily accessed cobalt pre-catalysts in combination with NHC ligands can catalyze the cross-coupling of aryl chlorides and bromides with alkyllithium-activated arylboronic pinacolate esters. Preliminary mechanistic studies hint towards cobalt reduction to Co(0) during catalysis. The extended substrate scope demonstrates the efficacy of the process for various aryl halides without the aid of any directing group. Furthermore, novel derivatives of a neuro-protective drug edaravone, have been synthesized utilizing this protocol that echoes the broader range of applications of the study. Finally, the development of a small library of derivatives based on edaravone, has been achieved through an iron-catalyzed, substrate directed ortho-arylation procedure. The preliminary computational assessment predicts that these synthesized analogues can inhibit the human enzyme, monoamine oxidase-B, more strongly than the parent edaravone.