The present paper is an overview of new methods for the asymmetric synthesi
s of different types of alpha-amino acids. These methods are based on alkyl
ation and condensation reactions of glycine and alanine imine derivatives,
which can be carried out under very mild and simple reaction conditions. Th
e enolates generated from these types of reagents are very soft and can be
alkylated in a highly diastereoselective manner, even at room temperature,
by using chiral templates or asymmetric PTC conditions. These methodologies
afford monoalkylated and dialkylated alpha-amino acids as well as heterocy
clic derivatives. In the case of cyclic imine derivatives with oxazinone or
pyrazinone structures, the condensation reaction under PTC conditions or w
ith Eschenmoser's salt allows the preparation of chiral alpha,beta-didehydr
o-alpha-amino acid derivatives which can be hydrogenated, cyclo-propanated
or submitted to Diels-Alder cycloadditions to afford N-methylated and cycli
c alpha-amino acids.