Carbohydrate based chiral iodoarene catalysts for enantioselective dearomative spirocyclization

Organocatalysis using chiral iodoarenes enables many different enantioselective chemical reactions with cheap, easily accessible and robust catalysts. Carbohydrates have often been used as starting materials for the synthesis of chiral ligands for transition metal catalysts. Here, we now present the synthesis of the first carbohydrate based iodoarene catalysts which can be synthesized in one step starting from known compounds. These catalysts were used for oxidative spriolactonization of 3-(1-hydroxynaphthalen-2-yl)propanoic acid to afford the corresponding spirolactone in yields up to 77% and enantiomeric ratios er up to 80:20.