Non-phosgene route to unsymmetrical ureas from N-Cbz-α-amino acid amides
作者:Ebrahim H. Ghazvini Zadeh、Nader E. Abo-Dya、Ania C. Sotuyo、Ion Ghiviriga、C. Dennis Hall
DOI:10.1016/j.tetlet.2013.07.141
日期:2013.10
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 Synthesis of Aza-peptides: En Route to an Aza-Leuenkephalin Analogue
作者:Nader E. Abo-Dya、Suvendu Biswas、Akash Basak、Ilker Avan、Khalid A. Alamry、Alan R. Katritzky
DOI:10.1021/jo302251e
日期:2013.4.19
with an ester bond 26b, and a hybrid azatripeptide with an ester bond 28. A new protocol for the synthesis of N-Pg-azatripeptides 33a,b and 35a,b, each containing a natural amino acid at the N-terminus, avoids the low coupling rates of the aza-amino acid residue and enables the solution-phase synthesis of an azaphenylalanine analogue of Leu-enkephalin 40.
Oxyazapeptides: Synthesis, Structure Determination, and Conformational Analysis
作者:Suvendu Biswas、Nader E. Abo-Dya、Alexander Oliferenko、Amir Khiabani、Peter J. Steel、Khalid A. Alamry、Alan R. Katritzky
DOI:10.1021/jo401234g
日期:2013.9.6
we report the synthesis, X-ray structure determination, and conformationalanalysis of a novel class of heteroatom-modified peptidomimetics, which we shall call “oxyazapeptides”. Substituting the typical native N-Cα bond with an O-Nα bond creates a completely new, previously unknown family of peptidomimetics, which are hydrolytically stable and display very interesting conformational behavior. Force