A simple, green and catalyst-free novel protocol is developed for the synthesis of medicinally important spiro[indole-3,2'[1,3]-thiazine]-2,4'-dione and spiro[acenaphthylene-1,2'-[1,3]thiazine]dione libraries by the tandem reaction of readily available reagents in 1-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF₆]. The ionic liquid has been used as a solvent as well as catalyst for this reaction. This reaction proceeded smoothly in good to excellent yields and offered several other advantages including short reaction time, simple experimental workup procedure and no by-products. The synthesized compounds were subjected to antimycobacterial efficacy against Mycobacterium tuberculosis H37Rv strain and DNA cleavage activity.

Different types of corroles and porphyrins are synthesized from substituted aldehydes and pyrrole. The current synthetic method involves iodine as catalyst and proceeds at room temperature itself. By varying the amounts of reactants (i.e., pyrrole and aldehydes), the corrole and porphyrins were obtained ingood to excellent yields. These products were characterized by ¹H-NMR, UV-visible, and HRMS techniques. The reaction approach utilizes the readily available pyrrole and substituted aldehydes as starting materials and makes this reaction highly attractive in diversity-oriented synthesis