Rich chemistry of nitroso compounds

Nitrosobenzene or nitrosopyridine are found to be attractive electrophiles in catalytic enantioselective carbon–nitrogen and/or carbon–oxygen bond forming reactions. In the presence of designer Lewis or Br?nsted acid catalysts, catalytic enantioselective O- and N-nitroso aldol reaction or nitroso Diels–Alder reaction proceed smoothly. The scope and limitation of new catalytic processes are described.