Enantioselective Synthesis of Ring-Fused Spiroannulated 1,2,3-Thiadiazole Derivatives.

An organocatalytic enantioselective domino α-amination/oxidative coupling/cyclization of thioamides to azodicarboxylates catalyzed by an easily available organic catalyst has been developed. The key step, oxidative coupling, is smoothly fulfilled in air. Optically active spiroannulated 1,2,3-thiadiazole derivatives are obtained with high yields and enantioselectivities for the first time.