Cupreine Base – Fine Chemical

Cupreine Base (CAS-No. 524-63-0), as well as its pseudoenantiomer Cupreidine, are highly enantioselective bifunctional Cinchona organocatalysts. They can be used for a wide range of enantioselective reactions such as Michael additions, Mannich, Henry, Friedel-Crafts, reactions etc..

For further examples please review the free of charge chiral catalyst search data base.

Cleavage of the C6′ methoxy group in Cinchona Alkaloids affords organocatalysts with a phenolic OH group. Despite its position far away from the stereocenters, this hydroxy group proves crucial to obtain high enantioselectivity in many synthetically relevant reactions like Michael additions. The electrophile is activated via the C6`-hydroxy group. On the other hand the free C6’ hydroxy group can be further functionalized to improve catalytic performance. Deprotonation of the phenolic OH group and quaternization of the quinuclidine nitrogen leads to enantioselective Cinchonium bataines being highly efficient (99 % ee) as catalysts in asymmetric proton transfer catalysis such as imine isomerization.

Physical properties

Cupreine Base (CAS-No.: 524-63-0) is a beige to pale yellow, light yellow powder soluble in methanol. Furthermore it is sparingly soluble in water, diethyl ether, chloroform and petrol ether. The melting point is in the range of 177-182 °C. This compound is not hygroscopic and contains less than1.0 % water. Cupreine could be stored at ambient conditions in well-closed, light-resistant containers.

Synonyms

O-Demethylquinine, Desmethylquinine, 6´-Hydroxycinchonidine, (8S,9R)-6`-Hydroxycinchonan-9-ol, (8α,9R)-6`-Hydroxycinchonan-9-ol and (8S,9R)-Cinchonan-6`,9-diol