Applications of Carbohydrate-Based Organocatalysts in Enantioselective Synthesis

Carbohydrates have been widely used for stereochemical control, either as chiral auxiliaries or as ligands. Their natural abundance and rigidity of structure, together with the presence of many functional groups, have also in recent years made them attractive chiral modular units for the assembly of bifunctional organocatalysts. Applications have ranged from the more complex bifunctional carbohydrate-based amine-(thio)ureas and prolinamides to simple amino alcohols. The presence of many hydroxy groups and their consequent water solubility has allowed for the study of reactions in aqueous media. Nowadays they have been applied to many reactions such as the aldol, Michael, Stetter, Biginelli, Morita-Baylis-Hillman, decarboxylative Mannich and other reactions, and even to the multistep synthesis of known drugs. This review provides an overview of developments in this field in the period from 2009 to mid-2014.