An efficient domino approach has been developed for the synthesis of polyheterocyclic derivatives constituting pyrrole moiety. Lewis acid catalyzed reaction of 2‐substituted‐2‐hydroxy‐indane‐1,3‐diones and 1,4‐benzoxazinone derivatives resulted in the formation of polyheterocyclic compounds under metal‐free and mild conditions in good to excellent yield. The reaction is highly regioselective for C−C and C−N bond construction proceeded via intramolecular [3+2] cycloaddition reaction. The protocol is highly efficient, obviates column chromatography and the products are obtained by simple filtration followed by washing with solvent.

A metal- and base-free, robust, and convenient approach for the synthesis of isoxazoline derivatives is reported. This protocol involves 1,3-dipolar cycloaddition between in situ generated nitrile oxides from the corresponding aldoximes using [hydroxy(tosyloxy)iodo]benzene (HTIB, Koser’s reagent) and maleimides, styrene and acrylonitrile. The described methodology is very attractive as it is operationally simple, has broad scope, and does not require any base, metal, or other additives.