(R)-(-)-VAPOL hydrogenphosphate is a useful chiral Bronsted acid catalyst in the addition of sulfonamides to Boc-activated aryl imines. It is a Catalyst involved in desymmetrization of meso-aziridines and asymmetric aza-Darzens aziridine synthesis. It is also a enantioselective ring-opening of mono-and bicyclic N-acyl meso aziridines, condensation of aldehydes with amino benzenesulfonamides and Pictet-Spengler reactions.
