Tributylphosphane-promoted (3 +2)‎ annulation of 3-hydroxyoxindoles with acrylates : synthesis of spirocyclic oxindole-lactones

Abstract EN

The tributylphosphane-promoted [3 +2] annulation reactions of 3-hydroxyoxindoles with acrylates have been developed to give a variety of pharmaceutically attractive spirocyclic oxindole-lactone derivatives in good to excellent yields.

The structures of all the compounds were confirmed by 1H NMR, 13C NMR and HRMS.

This metal-free procedure features low costs of the reagents and materials, mild reaction conditions, non-toxicity and easy handling for scalable synthesis.