Abstarct: Heterocyclic compounds are one of the largest and most diverse family of organic compounds. Nitrogen heterocycles play a fundamental role in biological processes, pharmaceutical industry, materials science, and they are widespread in natural products. In this research work, some new nitrogen heterocycles were synthesized via carbon-carbon and carbon-nitrogen coupling reactions in the presence of the palladium and copper catalysts. 1. Multi-component synthesis of a new 1,4-disubstituted pyrrolo[1,2-a] quinoxalines from 3-substituted 2-chloroquinoxaline, propargyl alcohol, and secondary amines in water in the presence of the palladium catalyst. 2. One-pot synthesis of a new 1-amino-substituted pyrrolo[1,2-a]quinoline-4-carboxylate esters from copper-free Sonogashira coupling reaction of alkyl 2-chloroquinoline-3-carboxylates, propargyl alcohol, and secondary amines in the presence of triethylamine in CH3CN. 3. A novel pathway synthesis of 1,5-disubstituted pyrrolo[1,2-a] quinazolines using 2-chloro-4-substituted quinazolines, propargyl alcohol, and secondary amines in the presence of triethylamine in CH3CN through palladium-copper-catalyzed reactions. 4. Synthesis of a new derivatives of 1,2,3-triazole-lixnked quinazoline scaffold from 2-chloro-N-(prop-2-ynyloxy)quinazoline-4-amine or 2-chloro-N-(prop-2-ynyloxy)quinazoline-4-amine with aromatic azides using the copper-catalyzed click reaction in aqueous ethanol. The structures of all the synthesized compounds were confirmed by the spectroscopic data. For some derivatives of the synthesized compounds, the pharmaceutical and biological properties such as the anti-oxidant and anti-bacterial activities were examined.