Molecular sieve 4 Ã generates nitrile oxides from hydroximoyl chlorides. Development of catalyzed enantioselective nitrile oxide cycloadditions to monosubstituted alkenes

The effective generation of nitrile oxide 1,3-dipoles from hydroximoyl chlorides can be achieved with powdered molecular sieves 3 Å and 4 Å as mild solid bases. Rate of nitrile oxide generation depends upon the choice of reaction solvents, among which alcohols are the best media. A catalytic process is achieved by use of a catalytic amount of amine in the presence of MS 4 Å leading to the amine-catalytic generation of nitrile oxides. This new synthetic method can be applied to the catalytic enantioselective nitrile oxide 1,3-dipolar cycloaddition reactions with monosubstituted alkenes.