Recent Advances in the Synthesis of Unnatural α-Amino Acids - An Updated Version

The synthesis of unnatural α-amino acids is an area of research that has gained a lot of attention in recent years. The availability of synthetic methods for novel unnatural α-amino acids derivatives and related compounds will be critical in the de novo design of molecules that mimic the conformation of natural, active peptides. These molecules - peptidomimetics - are designed to display high receptor affinity and selectivity, in addition to enhanced bioavailability and metabolic stability. This review presents and discusses selected synthetic methodologies leading to unnatural α-amino acids, including chiral catalysts that enable enantioselective synthesis and microwave-assisted synthesis. Solid phase synthesis and construction of organometallic α-amino acids reveal the scope of influence that this field has in organic chemistry. Additionally, the article is aimed to provide a brief insight into biosynthetic approaches to the synthesis of α-amino acid derivatives, thus providing the reader with an overall appreciation of the field. For the purpose of this issue our previous review on the unnatural α-amino acids synthesis [Perdih A. and Sollner Dolenc M. Curr Org. Chem. 2007, 11, 801-832] has been revised and updated and discusses also selected contributions covering the period from 2007-2010. Keywords: Unnatural α-amino acids, peptidomimetics, amino acid derivatives, synthesis, neurotransmitters, neuromodulators, hormones, paracrine factors, cytokines, antigens, Peptide molecules, photolytic degradation, stereo-electronic, covalent or noncovalent, glycomimetics field