Chemoenzymatic synthesis and application of a new, easily chiral auxiliary for the synthesis of peptidomimetics via an Ugi reaction
摘要:
A new chiral auxiliary derived from alpha-phenylethylamine, alpha-(2,4-dimethoxyphenyl)ethylamine is presented. It significantly expands upon the application of cc-phenylethylamine derivatives used as chiral auxiliaries. A straightforward, chemoenzymatic synthesis of non-racemic alpha-(2,4-dimethoxyphenyl)ethylamine is described and the new chiral auxiliary applied to an asymmetric Ugi reaction. The mild conditions used for the cleavage of the auxiliary allowed to obtain chiral, non-racemic peptidomimetics possessing reactive alpha,beta-unsaturated double bonds.(C) 2014 Elsevier Ltd. All rights reserved.
Amidation of α-Amino Acids Using Dichloro(methyl)(3,3,3-trifluoropropyl)silane and Imidazole without Conventional Protection and Deprotection of α-Amino Group
Amidation of amino acids using dichloro(methyl)(3,3,3-trifluoropropyl)silane (MTFPSCl2) and imidazole is described. MTFPSCl2 activates the carboxy group and protects the α-aminogroup of amino acids. The amidation proceeded with 19 amino acids and 19 amines, including α-branched amines and anilines; the corresponding amino acid amides were synthesized in good-to-high yields (up to 96%) with low-to-no