Water‐Assisted Passerini Reactions under Mechanochemical Activation: A Simple and Straightforward Access to Oxindole Derivatives

A protocol based on the Passerini Multi-Component reaction (MCR) has been developed for facile, efficient, environmentally benign and atom economical synthesis of a small library of biologically important oxindole derivatives employing isatin, benzoic acid and substituted isocyanides. In contrast to the conventional approach, which requires the use of toxic organic solvents, Passerini reactions were completed in 10-15 minutes under mechanochemical conditions with excellent yields. The protocol described below allows the modular synthesis of diverse compounds under green chemistry principles, specifically in favourable environmental conditions, with great atom economy, shorter reaction time, cleaner reactions with improved yields, and experimental simplicity.