Greener chemistry on the synthesis and cycloaddition reactions

The utility of nitrones in synthetic organic chemistry has been widely illustrated. The nitrone moiety can be regarded as a 3 centered dipolar 4 system, which enables 1,3-dipolar cycloaddition reactions with different dipolarophilic reagent to occur. 1,3-dipolar cycloaddition reaction between a nitrone and an olefinic dipolarophiles is an efficient method for the synthesis of isoxazolidine and isoxazoline ring systems. Nitrones are also versatile intermediates for the synthesis of natural products and many biologically interesting molecules. Owing to the labile nature of the N–O bond under mild reducing conditions, isoxazolidines provide easy access to a variety of fascinating 1,3-difunctional amino alcohols. To run a chemical reaction under an environment friendly condition is a challenge now-adays. The development of environmentally benign chemical processes (aqueous phase synthesis, microwave induced reactions and ionic liquids as solvent) have received much attention in recent years.