Platinum-Catalyzed Tandem Cycloisomerization Reaction of Benzoendiynyl Esters: Regioselective Long-Range 1,5-Acyl Migration

A PtII-catalyzed intramolecular chemo- and regioselective pentannulation/long-range 1,5-acyl migration reaction is described. This cascade cycloisomerization protocol produces a wide variety of benzofulvene diketones in good to excellent yields with exclusively the Z configuration of the exocyclic double bond of the final product. The 18O isotope experiment together with 13C NMR, HRMS, and HMBC analyses confirmed an interesting long-range acyl rearrangement process in this transformation.