Solution-phase synthesis of novel seven-membered cyclic dipeptides containing ¦Á- and ¦Â-amino acids

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• 作者：Erika Jim¨¦nez-Gonz¨¢lez ; C. Gabriela ¨¢vila-Ortiz ; Rodrigo Gonz¨¢lez-Olvera ; Jorge Vargas-Caporali ; Georges Dewynter ; Eusebio Juaristi
• 关键词：Cyclic dipeptides ; ¦Â-Amino acids ; Amino acid coupling reagents ; Phenylphosphonic dichloride ; Conformational analysis of cyclic dipeptides
• 刊名：Tetrahedron
• 出版年：2012
• 出版时间：25 November, 2012
• 年：2012
• 卷：68
• 期：47
• 页码：9842-9852
• 全文大小：993 K

文摘

A convenient synthetic procedure for the preparation of seven-membered cyclic ¦Á,¦Â-dipeptides is described. Following coupling of N-protected ¦Á-amino acids with N-substituted ¦Â-amino acid tert-butyl esters, that affords linear ¦Á,¦Â-dipeptides, the protecting groups at the terminal functionalities were removed and the open-chain dipeptides were cyclized with phenylphosphonic dichloride, PhP(O)Cl₂, to give the desired cyclic ¦Á,¦Â-dipeptides in good yields. NMR studies, X-ray diffraction analysis, and DFT calculations provided evidence for the conformation adopted by these cyclic dipeptides in solution, in the solid-state, and in the gas phase.