A Highly Strained Planar‐Chiral Platinacycle for Catalytic Activation of Internal Olefins in the Friedel–Crafts Alkylation of Indoles

Activation by deformation: A planar-chiral platinacycle readily prepared by diastereoselective cycloplatination enables the enantioselective intramolecular hydroarylation of indoles having disubstituted Z olefins (see scheme; Ts=p-tolylsulfonyl). Sufficient activity is achieved by a combination of highly strained catalyst geometry and accelerated olefin coordination. This application represents the first highly enantioselective reaction catalyzed by a platinacycle.