Electrophilic Activation of Alkynes for Enyne Cycloisomerization Reactions with in Situ Generated Early/late Heterobimetallic Pt-Ti Catalysts.

In situ formation of heterobimetallic Pt-Ti catalysts enables rapid room temperature catalysis in enyne cycloisomerization reactions. The Lewis acidic titanium atom in the ligand framework is shown to be essential for fast catalysis. A range of enyne substrates are efficiently cyclized to carbocycles and heterocycles in high yield.