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-pi-alkyne intermediates. This cyclization works not only for terminal alkynes but also for internal alkynes.