[3+2] Cycloaddition Reactions of 2‐Ylidene Acenaphthylenones with 3‐Benzylidene Succinimides and 1,4‐Benzoxazinone Derivatives

Abstract

A base-catalyzed novel [3 + 2] cycloaddition reaction between arylidene-1-phenyl succinimides and alkylidene acenaphthylenones is carried out to access succinimide substituted spiro[acenaphthylenone-cyclopentane]fused scaffolds with high regio-and stereo-selectivity under mild conditions. The reaction of alkylidene acenaphthylenones with 1,4-benzoxazinone deriv-atives under the influence of environmentally benign iodine afforded polyheterocyclic compounds embedded with pyrrole moiety. This metal-free synthesis is highly efficient and atom economic and the protocol obviates column chromatography. The products are isolated by simple decantation followed by washing with solvent.

PTSA‐Catalyzed [3+2] Cycloaddition of in Situ Generated 3‐Ylidene Oxindoles with Coumarin‐Based N‐Phenyl Enamine Derivatives

“…Proton transfer in A leads to Michael adduct B , which undergoes intramolecular cyclization via the attack of imine nitrogen on the carbonyl group of benzoyl carbonyl moiety to generate cyclic aminol C . Finally, the dehydrative aromatization [25] of C liberates pyrrolocoumarin 3 a .…”