Asymmetric Alkylation of Amide Enolates with Pseudoephedrine and Ephedrine as Chiral Auxiliaries—Unexpected Influence of Additives?

Abstract

The self-assembly of enolates can be controlled by the addition of nonstoichiometric amounts of metal salts. New findings on the structure-reactivity relationship of enolates and chemo-, regio-, and diasteroselectivities in their reactions with electrophiles are discussed. This article was prompted by a recent report by Myers et al. on a new method for the alkylation of amide enolates with pseudoephedrine as a chiral auxiliary [Eq. (a)].