Protected (Natural) Amino Acids
Protected (Natural) Amino Acids
Protected amino acids refer to those amino acids in which the amine group, the carboxylic acid group, or both groups are protected. In organic synthesis, N-protected amino acids are often employed as important intermediates in various areas such as peptide synthesis, asymmetric synthesis, medicinal chemistry, and polymer chemistry. In peptide synthesis, by protecting the amine group of one amino acid and the carboxylic acid group of another amino acid, a specific amide bond can be formed. On repeating this process, peptides are formed.
In recent years, palladium bearing monoprotected chiral amino acid ligands have been utilized for enantioselective C-H bond activation reactions. In the area of pharmacology, a number of N-acylated L-alpha-amino acids are used as therapeutic agents, specifically as mucolytic agents and in antihypertensive drugs. Certain N-acetylated alpha-amino acids are of particular interest in parenteral nutrition. Some esters of amino acid are used as a local anaesthetic. For a review of amino acid protecting groups and there use in synthetic transformations, see Amino Acid-Protecting Groups, Llobet, A. I-., Chem. Rev. 2009, 109, 24552504.