Visible Light Induced One-pot Synthesis of Spirocyclopropyl Oxindoles from Isatin Derivatives and Glycine Ester Hydrochloride

An integrated one pot protocol for the in situ generation of hazardous alkyl diazoacetates (from glycine ester hydrochloride) and their subsequent reaction with 3-alkenyl oxoindoles (generated via the in situ Wittig reaction from isatin derivatives) to afford diastereomeric mixtures of spirocyclopropyl oxoindoles in toluene at room temperature is presented. Spirocyclopropyl oxoindoles are interesting building blocks prevalent in many active pharmaceutical ingredients and in natural products. This protocol is devoid of any metal catalysts or bases.