(11AS)-12-hydroxy-1,10-dimesityl-4,5,6,7-tetrahydrodiindeno[7,1-de:1′,7′-fg][1,3,2]dioxaphosphocine 12-oxide is a chiral phosphoric acid catalyst for a variety of enantioselective transformations, especially for carbon-carbon and carbon-heteroatom bond-forming reactions.