Camphor sulfonyl hydrazines (CaSH) as organocatalysts in enantioselective Diels-Alder reactions.

Cyclic sulfonyl hydrazine was demonstrated for the first time as a new functionality for organocatalysis. A series of six-membered cyclic hydrazines derived from camphor sulfonic acid were synthesized. With trichloroacetic acid as cocatalyst, they are efficient organocatalysts for enantioselective Diels−Alder reactions with good chemical yields and up to 96% ee. The reactions took place in brine at 0 °C to room temperature.