Asymmetric Catalysis by Alkaloids Wynberg

For a recent review see H. Wynberg, Asymmetric catalysis by alkaloids. Top. Stereochem., 1986,16,87. 

Wynberg H. Asymmetric catalysis by alkaloids. In Eliel EL, Wilen SH, Allinger NL, editors. Topics in stereochemistry. Volume 16. New York John Wiley 1986. p 87-129. 

In the second chapter, Hans Wynberg describes one facet—namely asymmetric catalysis—of the currently very active field of asymmetric synthesis. Wynberg and his co-workers have devised efficient asymmetric syntheses catalyzed by cinchona alkaloids. Several of these reactions are reviewed and rationalized by means of mechanistic models. 

Asymmetric epoxidation catalyzed by chiral phase-transfer catalysts is another reaction which has been extensively studied following an initial report by Wynberg [2,44]. Shioiri et al. further improved the enantioselective epoxidation of naphthoquinones under cinchona alkaloid-derived chiral phase-transfer catalysis [45],... 

Phase-transfer catalysis has been widely been used for asymmetric epoxidation of enones [100]. This catalytic reaction was pioneered by Wynberg et al., who used mainly the chiral and pseudo-enantiomeric quaternary ammonium salts 66 and 67, derived from the cinchona alkaloids quinine and quinidine, respectively [101-105],... 

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