Asymmetric Organocatalyzed Synthesis of α‐Aminophosphinates via Thiourea Anion‐Binding Catalysis

Thioureas catalyze the reaction of phosphonites with in situ‐generated isoquinolinium salts to give C and P‐stereogenic α‐aminophosphinates in high enantioselectivity (up to 96%) and yield (up to 95%). Low diastereoselectivity was obtained and this is rationalized in the context of a mechanistic proposal involving anion‐binding catalysis of the P‐C bond formation step followed by uncatalyzed Arbuzov collapse. The scope of the reaction, including a g‐scale example, was demonstrated.