Cupreines and cupreidines: an emerging class of bifunctional cinchona organocatalysts.
In the steadily expanding field of organocatalysis, cinchona alkaloids play a prominent role. Until the late 1990s, bifunctional catalysts based on this scaffold relied exclusively on the C9-hydroxy group as the hydrogen-bond donor. Recently, new cinchona catalysts have been developed that feature a phenolic OH group in the C6' position-a structural feature that allows a diverse set of reactions to be catalyzed in a highly stereoselective fashion. This Minireview describes the scope and modes of action of this new class of asymmetric bifunctional organocatalysts.
Marcelli
Tommaso
T
Van't Hoff Institute for Molecular Sciences (HIMS), Universiteit van Amsterdam, Nieuwe Achtergracht 129, 1018WS Amsterdam, The Netherlands.
van Maarseveen
Jan H
JH
Hiemstra
Henk
H