AbstractThe selective C7‐allylation of indolines with allyl bromide under ruthenium catalysis has been revealed here. Under established reaction conditions, C7‐allylation of various indolines, including drug compounds, was accomplished with good selectivity and yields. Based on combined experimental and density functional theory (DFT) studies, the olefin insertion route was energetically favorable among four possible pathways. Experimental and DFT studies further revealed that the C−H activation is a reversible rate‐limiting step.