In this investigation, at first, synthesis of propyleneimine (2-methylaziridine) was investigated. The different catalysts were prepared based on TiO 2 and nano-TiO 2 , fumed silica and SiO 2 nanoparticles by addition of cesium and yttrium as promoters, then their efficiency on the hydration reaction of isopropanolamine in gas phase were compared. Among these catalysts, the best catalyst with respect to the highest conversion and selectivity was selected and characterized. In the second section, new polyimides and poly(ester-imide)s containing triazoles in the main chain were prepared via click coupling. These polymers were synthesized by the polymerization of dialkynes including imide linkages with diazides in the presence of Cu (I) as catalyst in good yields. Their thermal stability was evaluated using thermogravimetric (TGA) analysis under the nitrogen atmosphere and all of them indicated good thermal stability. In the third section, the synthesis of ortho -palladated 2-methoxyphenethylamine and its application in C-C cross and homo coupling reactions were studied under both conventional and microwave irradiation conditions. The ortho -palladated complex was applied successfully in the Heck reaction, Suzuki reaction, homocoupling of aryl halides and cyanation. Microwave irradiation led to dramatically reduced reaction times and higher yields in comparison to the conventional reflux conditions.