Asymmetric α-2-tosylethenylation of N,N-dialkyl-L-amino acid esters via the formation of non-racemic ammonium enolates.

Asymmetric α-2-tosylethenylation of (S)-2-(pyrrolidin-1-yl)propanoic acid esters was shown to produce good yields with high enantioselectivities. The reaction proceeds via the formation of a non-racemic ammonium enolate without an external source of chirality.