Chemical process synthesis of beta-amino acids and esters.

The importance of beta-amino acids and esters for the synthesis of potential therapeutic agents and biologically active compounds is well known and the subject of this special issue. This review outlines some of the recent approaches reported for the synthesis of both racemic and enantiomeric beta-amino acids and esters with emphasis on those used for large scale production. This compilation is written from a chemical process perspective focusing on the practical application of these processes for large scale synthesis. A survey of procedures described in patent publications as well as current advances from chemical process research groups and results from our laboratory are included with emphasis on asymmetric Michael-type additions, addition of metal enolates to imines/sulfinimines, classical and enzymatic resolutions, and reduction of enantiomeric enamines.