A Selenenium-Bridged 10-Boratriptycene Lewis Acid

Summary: A series of catecholato phosphonium ions, including the first stable bis(catecholato)-substituted derivatives, have been isolated and fully characterized. These cations are among the most potent Lewis acids in literature known scales. The superacidic behavior is achieved by structural constraints and energy decomposition analysis. Furthermore, a chiral Lewis superacid with tunable scaffold has been synthesized, showcasing new reactivity modes through phosphorus-ligand cooperativity.