This paper describes an original methodology for peptide bond synthesis avoiding toxic solvents and reactants. Ball-milling stoichiometric amounts of Boc-protected α-amino acid N-carboxyanhydrides (Boc-AA-NCA) or Boc-protected α-amino acid N-hydroxysuccinimideesters (Boc-AA-OSu) with α-amino acid alkyl ester salts in the presence of NaHCO3 and a minimal quantity of EtOAc led to the production of di-
The unprecedented electrophilic iodo-mediated cyclization of α-amino-ynones afforded enantiomerically enriched β-iodopyrrolin-4-ones in excellent yields under mild conditions. The starting substituted α-amino-ynones were obtained from the chiral pool by selective mono-addition of an organolithium to optically pure N-protected carboxyanhydrides of amino acids (UNCAs).
N-protected γ-amino-β-keto-esters were synthesized from the corresponding N-protected N-carboxyanhydride (UNCAs) by reaction with the lithium enolate of ethyl acetate in good yields. These compounds are precursors of statine derivatives.
Rapid, one-pot synthesis of urethane-protected tripeptides
作者:Yun-Fei Zhu、William D. Fuller
DOI:10.1016/0040-4039(94)02391-n
日期:1995.2
Urethane-protected tripeptides are synthesized in solution, without isolation or purification of intermediates, using urethane-protected N-carboxyanhydrides as coupling reagents and hydrogenation for removal of N-protection.
N-protected α-alkyl-γ-amino-β-keto-esters were synthesized from the corresponding N-urethane protected N-carboxyanhydride (UNCAs) by reaction with lithium enolates in fairly good yields. These compounds are candidates for mimicking the transition state analogue in enzyme inhibitors. They constitute, however, interesting and diverse building blocks for using in combinatorial chemistry.