Design and synthesis of novel χ2-constrained phenylalanine, naphthylalanine, and tryptophan analogues and their use in biologically active melanotropin peptides
作者:Wei Wang、Minying Cai、Chiyi Xiong、Junyi Zhang、Dev Trivedi、Victor J Hruby
DOI:10.1016/s0040-4020(02)00588-4
日期:2002.9
A series of novel hydrophobic, bulky chi(2)-constrained phenylalanine, naphthylalanine, and tryptophan derivatives was designed and synthesized. The key steps involved asymmetric hydrogenations of alpha-enamides using Burk's DuPHOS-based Rh(l) catalysts to give high enantiomerically pure alpha-amino acid derivatives. The subsequent Suzuki cross couplings of the amino acid analogues with boronic acid derivatives afforded these aromatic substituted amino acids in high yields and with high enantioselectivity. The incorporation of these novel chi(2)-constrained amino acids into peptides and peptidomimetics provides fruitful information in the development of peptide and peptidomimetic ligands of melanotropins and an understanding of the interactions between ligands and receptors/acceptors. (C) 2002 Elsevier Science Ltd. All rights reserved.