Active Sites in Cinchona Alkaloids and Their Derivatives

Active Sites in Cinchona Alkaloids and Their Derivatives 

The presence of the quinuclidine base functionality makes them effective ligands for a variety of metal-catalyzed processes (Chapters 2-4). The most representative example is the osmium-catalyzed asymmetric dihydroxylation of olefins [9]. The metal binding properties of the quinuclidine nitrogen also allow to use cinchona alkaloids as metal surface modifiers, for example, in the highly enantioselective heterogeneous asymmetric hydrogenation of a-keto esters (Chapter 2). Both 

1) Metal binding ability chiral ligands or chiral modifiers 

However, in general, these active sites in cinchona alkaloids and their derivatives act in catalysis not independently but cooperatively that is, they activate the reacting molecules simultaneously. Furthermore, in many cases, the catalysis is also supported by a n-n interaction with the aromatic quinoline ring or by its steric hindrance. 

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