Regioselective Tele‐Substitution of Aroyl Chlorides via Activation by an Al/P Frustrated Lewis Pair

The development of tele‐substitution reactions is significant in organic synthesis. However, most reported tele‐substitutions have been limited to nucleophilic aromatic substitution. We report a regioselective tele‐substitution reaction of aroyl chlorides with silyl ketene acetals mediated by an ortho‐phenylene‐linked Al/P frustrated Lewis pair (FLP). Structural and computational analyses reveal that, in the aroylphosphonium intermediate generated from aroyl chlorides and the Al/P FLP, intramolecular activation by the aluminum center increases positive charge on the aromatic ring, facilitating regioselective dearomative nucleophilic addition. This transformation accommodates a broad range of aroyl chlorides, affording functionalized 2‐(4‐formylphenyl)acetic acid esters that serve as valuable synthetic precursors in pharmaceutical chemistry. This work expands the scope of tele‐substitution chemistry and establishes a novel strategy for the regioselective functionalization of aromatic compounds through FLP‐mediated activation.