Chemoselective Addition of Halomethyllithiums to Functionalized Isatins:A Straightforward Access to Spiro‐Epoxyoxindoles

An efficient, chemoselective approach to spiro‐epoxyoxindoles via the addition of chloromethyllithium followed by ring‐closure of the intermediate alkoxide is reported. Chemoselectivity is fully preserved in the presence of different electrophilic sites. The synthetic potential of selected spiro‐epoxyindoles has been exploited in the copper(I)‐catalyzed intramolecular oxyarylation of an alkyne and in the formation of N,N‐dimethylisoindigo via the addition of dihalocarbenoids.