Regio‐ and Stereo‐Selective Ring Opening of Cyclopropenes with Triflic Acid: en Route to Vinyl Triflates

Abstract Herein, we report a triflic acid‐mediated ring opening of cyclopropenes, affording vinyl triflates with high regio‐ and stereo‐selectivity. An intramolecular halogen transfer reactivity was also observed in this reaction, offering a tool to access the valuable vinyl chloride and bromide. The vinyl triflate products are applicable to palladium‐catalyzed cross coupling reactions, delivering various trisubstituted olefins and dienes with moderate yields.