143789-83-7Relevant academic research and scientific papers
Asymmetric synthesis of (2S,3S)- and (2R,3R)-α,β-dialkyl- α-amino acids via alkylation of chiral nickel(II) complexes of aliphatic α-amino acids with racemic α-alkylbenzyl bromides
Soloshonok, Vadim A.,Boettiger, Thomas U.,Bolene, Shawna B.
experimental part, p. 2594 - 2602 (2009/04/07)
This study has demonstrated that the stereochemical outcome of the direct alkylation of nickel(II) complexes derived from chiral Schiff bases of glycine, alanine, 2-aminobutyric acid, and leucine with racemic α-methylbenzyl bromide depends on the steric bulk of the corresponding amino acid residue. In particular, the alkylation of the alanine complex was found to proceed with a synthetically useful level (90% de) of stereoselectivity offering a concise synthesis of enantiomerically pure (2S,3S)- or (2R,3R)-α,α- dimethylphenylalanines. Georg Thieme Verlag Stuttgart.
New Amino Acids for the Topographical Control of Peptide Conformation: Synthesis of All the Isomers of α,β-Dimethylphenylalanine and α,β-Dimethyl-1,2,3,4-tetrahydroisoquinoline-3-carboxylic Acid of High Optical Purity
Kazmierski, Wieslaw M.,Urbanczyk-Lipkowska, Zofia,Hruby, Victor J.
, p. 1789 - 1795 (2007/10/02)
The synthesis of all four diastereomers of α,β-dimethylphenylalanine (4) as well as those of α,β-dimethyl-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (5 and 6) have been accomplished in high yield and high optical purity.Molecular mechanics calculations on the Nα-acetyl and N-methylcarboxamide derivatives of (3R,4R)-6 and (3R,4S)-5 indicate large and moderate energy stabilization for the gauche(-) but not the gauche(+) side-chain conformers of (3R,4S)-5 and (3R,4R)-6, respectively.By symmetry rules, the same holds for (3S,4R)-5 and (3S,4S)-6, respectively.Thus, these amino acids are potential building blocks for the topographical design of peptides (Kazmierski et al., J.Am.Chem.Soc. 1991, 113, 2275-2283) by providing acylated 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid derivatives in which a gauche(-) and not a gauche(+) side-chain conformation is energetically more stable for the L amino acid.Synthetic details and implications of these new amino acids for peptide and protein design are discussed.
