De-racemization of enantiomers versus de-epimerization of diastereomers--classification of dynamic kinetic asymmetric transformations (DYKAT).
ABSTRACT The isolation of single stereoisomers from a racemic (or diastereomeric) mixture by enzymatic or chemical resolution techniques goes in hand with the disposal of 50% (racemate) or more (diastereomeric mixtures) of the "undesired" substrate isomer(s). In order to circumvent this drawback, dynamic systems have been developed for the de-racemization of enantiomers and the de-epimerizations of diastereomers. Key strategies within this area are discussed and are classified according to their underlying kinetics, that is, dynamic kinetic resolution (DKR), dynamic kinetic asymmetric transformations (DYKAT), and hybrids between both of them. Finally, two novel types of DYKAT are defined.
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ABSTRACT: Enzymatic kinetic resolution of unsymmetrical 1,4-diols in combination with a ruthenium-catalyzed hydrogen transfer process led to a dynamic kinetic asymmetric transformation (DYKAT) of the least hindered alcohol. Oxidation of the second hydroxy group takes place under the reaction conditions leading to the formation of gamma-acetoxy ketones in high enantiomeric purity.The Journal of Organic Chemistry 01/2005; 69(26):9191-5. · 4.56 Impact Factor
- Angewandte Chemie. 01/2007; 119(10):1648-1651.
- Angewandte Chemie International Edition 01/2007; 46(10):1624-6. · 13.73 Impact Factor