Over the past two decades, significant progress developed in this direction by introducing a plethora of novel approaches such as combinatorial chemistry, multicomponent reactions, microwave and ultrasound-assisted reactions, solid phase syntheses etc. Among the multicomponent reactions (MCRs), those that involve three or more reactants reacting to each other in resulting one major specified product via one pot have been attracting much attention due to their obvious synthetic utility and numerous advantages such as minimization of the amounts of reagents, solvents, catalyst loading, easy to carry out, atom economy no requirement of isolation and purification of the intermediates, which dramatically decrease the amounts of the chemical waste, time investment and obtaining products in higher yields: when Alexandcompared with the corresponding linear multi-step synthesis. The current study is to develop new and practical methodologies for the synthesis of a broad variety of biologically active -aminonitriles (using propylphosphonic acid anhydride), alkyl/aryl aminophenols (using chitosan), 2-amino substituted 1,3,4-oxadiazoles (using graphene oxide) and 5-aryl pyrimidoquinolines.