Various aspects of the reaction of a chiral catalyst or reagent with a racemic or enantiopure substrate

A chiral catalyst or reagent may be used to create an asymmetric center on the components of a racemic mixture. The quantitative relationships between the various experimental data (ee's, fractional amounts of products, conversion) are given, and extended to the formation of regioisomeric products. The cases when products are not isomeric are also considered. The meaning of 'kinetic resolution' in these processes is discussed. Finally, it is shown that above results can be used to safely predict the behavior of a chiral substrate versus either enantiomers of a chiral catalyst or reagent. Indeed, regio-, diastereo- or chemoselective reactions on a chiral substrate can be achieved by the choice of the absolute configuration of an external chiral controller. (C) 2001 Elsevier Science Ltd. All rights reserved.