Synthesis of Novel Camphor‐Derived Bifunctional Thiourea Organocatalysts

Synthesis and catalyst performance of 2,3‐ (types B and C ) and 2,8‐disubstituted (type D ) thiourea bifunctional organocatalysts was attempted. The synthesis of catalyst of type B has, so far, not been realized, while catalysts of type C , i.e., the 2,3‐exo‐ and the 2‐endo‐3‐exo‐thiourea catalysts, were prepared in six steps starting from (+)‐camphor. The catalysts of type D were prepared from (+)‐camphor in eight steps. All the potential catalysts as well as most of the intermediate products were carefully structurally characterized. The thiourea bifunctional organocatalysts were tested in a model reaction of Michael addition of dimethyl malonate to trans‐β‐nitrostyrene. Chirality 27:39–52, 2015. © 2014 Wiley Periodicals, Inc.