Double [3+2] Cycloaddition of Nitrile Imine with a Thiazolo[3,2-a]indole Incorporated 2π-component -Experimental and computational investigation

A double (3+2) cycloaddition of nitrile imine with a thiazolo [3,2a]indole incorporated 2π-component, followed by ring openings is described here. Products incorporating two heterocyclic moietiesthiadiazole and pyrazole, were obtained in 72-83% yields by this reaction. Theoretical support for the reaction mechanism was obtained by the computational studies employing reduced density gradient (RDG) plot and activation energy calculations. The uniqueness of the reaction pathway, simple reaction conditions and the ease of product isolation are the highlights of this reaction. Effect of the compounds on cell viability was tested on MCF-7 cancer cell line and the mono-chloro substituted compound was found to exhibit significant cytotoxicity at a low treatment dose.