An iron(III)-catalyzed 1,3-dihydroisobenzofuran transferring reaction of indoles provides ap ractical synthetic protocol to access 3-substitutedi ndolesu nder mild conditions. This is the first example of a1 ,3-functional group transposition of a N-protected indole to give a3 -substituted indole derivative in good yield. Ap lausible mechanism has been proposed on the basis of deuterium-labeling and control experiments. Furthermore, after as imple oxidation, the obtained product could be easily transformed into 3-phthalide indole, ad rug candidate for treating Alzheimer'sd isease.The indole core is av ery common structuralm otif found in natural products and medicines.[1] Research on the indole alkaloids' biological activities and investigations into indole'sr eactivities have been carriedo ut extensively.[2] The natural products or drugs bearingi ndole cores often have remarkable bioactivities. For example, bioactivity studies showed that dragmacidin (Scheme 1) is at ype of serine/threonine protein phosphatase inhibitor that hasa nti-herpesvirus and anti-HIV effects; indomethacin has been used as aN SAID( nonsteroidal anti-inflammatory drug) for more than fifty years; citrinalin B,atype of prenylated indole alkaloid, had its total synthesis reported recently, [1h] which may help develop ad ifferent approacht o synthesize quinineo rm orphine derivatives. Some other indole-containing compounds have been applied as neuroprotection, anti-cancer compounds, antibiotics, etc.[3] With regard to indole'sr eactivity,i ti sw ell known that the 3-position of indole has the richest electron density and that this carbon site can act as the nucleophile to allow 3-substituted indole derivatives to undergo Friedel-Crafts-type reactions.To the best of our knowledge, the synthesis of 3-substituted indoles has always been as ignificantly demanding task for organic chemists working in indole chemistry.[4] As shown in Scheme 2, the previous methods to achieve this goal include simple Friedel-Crafts-type substitution, transition-metal-catalyzed CÀHb ond activation or cross-coupling, including crossdehydrogenative couplingb yu sing the nucleophilic nature of the 3-position of the indole (Scheme 2). However, 1,3-functionScheme1.Reported indole-based structures for drugs and natural products.Scheme2.Reported methodsfor the synthesis of 3-substituted indoles.