Iron(III)‐Catalyzed 1,3‐Functional Group Transposition Reactions: Synthetic Protocol to Access 3‐Substituted Indoles

An iron(III)‐catalyzed 1,3‐dihydroisobenzofuran transferring reaction of indoles provides a practical synthetic protocol to access 3‐substituted indoles under mild conditions. This is the first example of a 1,3‐functional group transposition of a N ‐protected indole to give a 3‐substituted indole derivative in good yield. A plausible mechanism has been proposed on the basis of deuterium‐labeling and control experiments. Furthermore, after a simple oxidation, the obtained product could be easily transformed into 3‐phthalide indole, a drug candidate for treating Alzheimer′s disease.