This PhD dissertation includes the synthetic studies of novel heterocycles like benzodithiophenes, benzodithiazoles and benzothieno-chromenones. A comprehensive protocol for such oxidative reactions and mechanistic studies of their cyclization pattern were undertaken. Furthermore, Pd(0) catalyzed chemoselective coupling reactions of brominated benzothiophenes, naphthalenes and naphthaquinones afforded a variety of mono, di and polyarenes. These reactions generally proceed with excellent chemoselectivity in favour of bromide group (Br > OTf) in all cases.