C3‐Selective Branched Allylation of (NH)‐Indoles via Zn(II)‐Catalyzed Strain Release of Vinylcyclopropanes

Vinylcyclopropanes (VCPs) are valuable feedstocks for allylation, cycloaddition, and ring expansion, driven by C─C bond cleavage of the strained cyclopropane ring. Herein, we describe the zinc‐promoted C3‐allylation of free‐(NH)‐indoles using VCPs. The observed branched selectivity may be attributed to a concerted ring‐opening process involving Zn(II)–bipyridine‐catalyzed activation of VCPs and rapid electrophilic substitution of indoles. A range of synthetic elaborations of the resulting adducts highlights the potential of C3‐allylated indoles.