Synthesis of the first C2-asymmetric phosphinine and its pyrylium precursor

The synthesis of the first C₂ chiral phosphinine (phosphabenzene) and its pyrylium salt precursor is reported. The chiral phosphinine is derived from (+)-camphor, is a crystalline air-stable solid and is shown to effectively form complexes with metals. A preliminary result using the phosphinine as a ligand for asymmetric catalysis is reported and rationalized structurally.