New developments in stereoselective palladium-catalyzed allylic alkylations of preformed enolates

Whereas the enantioselective palladium-catalyzed allylic substitution with 'soft', stabilized carbanions can be considered as established and versatile method today, nonstabilized, preformed enolates were used for this purpose only very reluctantly. This report focuses on progress made recently in combining pi-allyl palladium complexes with different metal enolates derived from carboxylic esters and ketones. The elaboration of protocols that permit enantioselective and - at the same time - diastereoselective allylic alkylations are emphasized in this report. The stereochemistry in the approach of the enolate to the pi-allyl palladium complex is also discussed.