Palladium‐Catalyzed Regioselective C(4)−H Fluoroalkoxylation of Indoles Through Weak Chelation Assistance

Abstract

Installing fluoroalkyl motifs into biorelevent indoles is particularly interesting due to their ubiquitous presence in drug molecules. Herein, we demonstrate the regioselective C4 fluoroalkoxylation of indoles using fluoroalcohols via palladium‐catalyzed chelation‐assisted C–H activation. The weak chelating benzoyl moiety at the C3 position acts as a directing group for remote C(4)–H fluoroalkoxylation of diversely substituted indoles. This methodology demonstrates a high level of regioselectivity and tolerates a range of crucial functional groups, yielding diverse trifluoroalkoxylated indoles in moderate to good yields. Removal of directing/protecting groups and further functionalization established the synthetic utility of the methodology. A preliminary mechanistic investigation is conducted by isolating the palladacycle intermediate and performing the deuterium scrambling study.