A green approach for the regio- and stereo-selective syntheses of (Z)-3-methyleneisoindoline-1-ones in aqueous medium

A high yielding novel methodology was developed for the regio- and stereo-selective syntheses of (Z)-3-methyleneisoindoline-1-ones from substituted 2-phenylethynyl benzamides, generated in situ from 2-(phenylcarbamoyl)phenyl-1-H-imidazole-1-sulfonates and corresponding alkyne by Cu-free Sonogashira cross-coupling–5-exo-dig-cyclization in aqueous medium under sonication. The compound could easily be purified by recrystallization from EtOAc without column chromatography.