23420-04-4Relevant articles and documents
Enantioselective synthesis of α-secondary and α-tertiary piperazin-2- Ones and piperazines by catalytic asymmetric allylic alkylation
Korch, Katerina M.,Eidamshaus, Christian,Behenna, Douglas C.,Stoltz, Brian M.,Nam, Sangkil,Horne, David
supporting information, p. 179 - 183 (2015/02/05)
The asymmetric palladium-catalyzed decarboxylative allylic alkylation of differentially N-protected piperazin-2- ones allows the synthesis of a variety of highly enantioenriched tertiary piperazine-2-ones. Deprotection and reduction affords the corresponding tertiary piperazines, which can be employed for the synthesis of medicinally important analogues. The introduction of these chiral tertiary piperazines resulted in imatinib analogues which exhibited comparable antiproliferative activity to that of their corresponding imatinib counterparts.
Anthranilic acid based CCK1 receptor antagonists: Blocking the receptor with the same 'words' of the endogenous ligand
Lassiani, Lucia,Pavan, Michela V.,Berti, Federico,Kokotos, George,Markidis, Theodoros,Mennuni, Laura,Makovec, Francesco,Varnavas, Antonio
experimental part, p. 2336 - 2350 (2009/09/05)
The anthranilic acid diamides represent the more recent class of nonpeptide CCK1 receptor antagonists. This class is characterized by the presence of anthranilic acid, used as a molecular scaffold, and two pharmacophores selected from the C-terminal tetrapeptide of CCK. The lead compound coded VL-0395, endowed with sub-micromolar affinity towards CCK1 receptors, was characterized by the presence of Phe and 2-indole moiety at the C- and N-termini of anthranilic acid, respectively. Herein we describe the first step of the anthranilic acid C-terminal optimization using, instead of Phe, aminoacids belonging to the primary structure of CCK-8 and other not coded residues. Thus we demonstrate that the CCK1 receptor affinity depends on the nature of the aminoacidic side chain as well as that the free carboxy group of the alpha-aminoacids is crucial for the binding. The R enantiomers of the most active compounds represent the eutomers of this class of antagonists confirming thus the stereo preference of the receptor. Moreover this SAR study demonstrates that the receptor binding pocket, that host the aminoacidic side chain, results much more tolerant respect to that accommodating the indole ring. As a result, an appropriate variation of the aminoacidic side chain could provide a better CCK1 receptor affinity diorthosis.
CLEAVAGE OF THE N-PChd GROUP FROM PROTECTED AMINO ACIDS AND PEPTIDES BY CATHODIC REDUCTION
Khalifa, M. Hassen,Rieker, Anton
, p. 1027 - 1030 (2007/10/02)
Amino acids and peptide esters protected by the PChd group can be deprotected cathodically under mild conditions.
