398125-83-2Relevant articles and documents
Convenient primary amidation of N-protected phenylglycine and dipeptides without racemization or epimerization
Noguchi, Takuya,Jung, Seunghee,Imai, Nobuyuki
, p. 394 - 396 (2014)
Primary amidation of N-protected phenylglycine and dipeptide proceeded easily to afford the corresponding amides in 57-95% yields with 99% ee and 81-99% de, respectively. The procedure is very easy to avoid racemization and epimerization of the products in the reactions by keeping exactly the reaction temperature at -15 C when the activation of carboxylic acids, followed by the reaction of the mixed carbonic carboxylic anhydride with NH4Cl.
Application of carbodiimide mediated Lossen rearrangement for the synthesis of α-ureidopeptides and peptidyl ureas employing N-urethane α-amino/peptidyl hydroxamic acids
Narendra,Chennakrishnareddy, Gundala,Sureshbabu, Vommina V.
supporting information; experimental part, p. 3520 - 3526 (2010/01/06)
Application of the Lossen rearrangement to the synthesis of N-urethane protected α-peptidyl ureas and ureidopeptides is reported. The carbodiimide mediated rearrangement of N-Boc/Z/Fmoc protected α-amino/peptide hydroxamic acids into isocyanates and coupling of the latter with the amino acid esters/peptide esters have been accomplished in a single-pot to obtain good yields of urea products. Synthesis of the ureidoalanine derivatives via the hydroxamate derivatives of N-protected aspartic acid has also been carried out using the same procedure.
