C3-Allylation of Indoles via an Iridium-Catalyzed Branch-Selective Ring-Opening Reaction of Vinylcyclopropanes

An iridium-catalyzed branch-selective ring-opening reaction of vinylcyclopropanes with indoles has been established, which afforded C3-allylindoles in generally good to excellent yields (up to 95%). Considering that no wastes were generated in the whole process and branch-selective ring-opening reaction of vinylcyclopropanes was rarely reported, this strategy not only can be regarded as a highly atom-economic approach for C3-allylindoles, but also will greatly enrich the chemistry of vinylcyclopropanes.