869772-05-4Relevant articles and documents
Non-phosgene route to unsymmetrical ureas from N-Cbz-α-amino acid amides
Ghazvini Zadeh, Ebrahim H.,Abo-Dya, Nader E.,Sotuyo, Ania C.,Ghiviriga, Ion,Hall, C. Dennis
, p. 5467 - 5469 (2013/09/23)
A convenient method toward the synthesis of α-amino acid-derived unsymmetrical ureas 2 is described herein. This route involves an interesting rearrangement of amides of N-Cbz-α-amino acids 1, which presumably entails the intermediacy of hydantoins that is followed by hydrolysis to afford unsymmetrical ureas 2 in quantitative yields and high purity.
Benzotriazole-mediated syntheses of depsipeptides and oligoesters
Avan, Ilker,Tala, Srinivasa R.,Steel, Peter J.,Katritzky, Alan R.
scheme or table, p. 4884 - 4893 (2011/07/30)
Reactions of O-Pg(α-hydroxyacyl)benzotriazoles with (a) unprotected α-hydroxycarboxylic acids, (b) amino acids, and (c) amines afforded, respectively, chirally pure (a) oligoesters, (b) depsidipeptides, and (c) amide conjugates (yields 52-94%). N-Pg(α-Ami
The efficient preparation of di- and tripeptides by coupling N-(Cbz- or Fmoc-α-aminoacyl)benzotriazoles with unprotected amino acids
Katritzky, Alan R.,Angrish, Parul,Suzuki, Kazuyuki
, p. 411 - 424 (2007/10/03)
N-(Cbz- or Fmoc-α-aminoacyl)benzotriazoles 2 and N-protected peptidoylbenzotriazoles 6 are coupled in aqueous acetonitrile solution with free amino acids or dipeptides to prepare: (i) 22 chirally pure dipeptides 5a-v (in an average yield of 82%) from N-(Cbz- or Fmoc-α-aminoacyl)benzotriazoles 2 and unprotected amino acids, (ii) five chiral tripeptides 7a-e (in an average yield of 75%) from N-protected peptidoylbenzotriazoles 6 and unprotected amino acids, (iii) one chiral tripeptide 7g (62%) from N-(Cbz- or Fmoc-α- aminoacyl)benzotriazole 2a and the free dipeptide 8. In all, N-(Cbz- or Fmoc-α-aminoacyl)benzotriazole derivatives of 17 of the 20 naturally occurring amino acids were used, including those containing the following unprotected side chain functionalities: alcoholic -OH (Ser), indole -NH (Trp), imidazole -NH, phenolic -OH (Tyr), -CONH2 (Gln, Asn), -SH (Cys), -CO2H (Glu, Asp), and -S-S (Cystine). Support for the complete retention of chirality was obtained by parallel experiments involving D-Ala, L-Ala, and DL-Ala for the preparation of di- and tripeptides. This and other evidence for chiral integrity was supported by NMR and HPLC analyses. Georg Thieme Verlag Stuttgart.