A green and efficient one-pot, sequential, multi-component protocol has been developed for the synthesis of some novel symmetrical bis-spirooxindole derivatives from the reaction of isatins, dihalides, malono derivatives and C–H activated carbonyl compounds or ketene aminal derivatives in the presence of potassium carbonate (K2CO3) in polyethylene glycol 400 (PEG-400) as a biodegradable polymeric solvent at room temperature. In this research, a variety of bis-spiro-indoline-pyranopyranes, bis-spiro-indoline-chromenes, bis-spiro-indoline-pyrido-pyrimidines, bis-spiro-indoline-imidazo-pyridines and bis-spiro-indoline-pyridines were obtained with excellent yields within short reaction time and without chromatographic separation.
