Platinum-Catalyzed Aromatization of Enediynes via a C−H Bond Insertion of Tethered Alkanes

PtCl₂ (5 mol %) is an effective catalyst for aromatization of enediynes via a C−H bond insertion of tethered alkanes. The reaction mechanism of this cyclization is proposed to involve platinum−π-alkyne intermediates. This cyclization works not only for terminal alkynes but also for internal alkynes.