- Enantioselective synthesis of α-secondary and α-tertiary piperazin-2- Ones and piperazines by catalytic asymmetric allylic alkylation
-
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.
- Korch, Katerina M.,Eidamshaus, Christian,Behenna, Douglas C.,Stoltz, Brian M.,Nam, Sangkil,Horne, David
-
supporting information
p. 179 - 183
(2015/02/05)
-
- Synthesis of hybrid cyclic peptoids and identification of autophagy enhancer
-
Cyclic peptoids are potential candidates for diverse biological activities. However, applications of cyclic peptoids are limited by the synthetic difficulties, conformational flexibility of large cyclic peptoids, and lack of secondary amide in the backbone. Herein, an elegant methodology for the synthesis of small and medium-size cyclic hybrid peptoids is developed. aN-Alkyl and aN-acyl substituents in N-(2-aminoethyl)glycine monomers enforce intra- and intermolecular cyclization to form stable sixand 12-membered cyclic products, respectively. NMR studies show inter- and intramolecular hydrogen bonding in six- and 12-membered cyclic peptoids, respectively. Screening of a cyclic peptoid library resulted in the identification of a potential candidate that enhanced autophagic degradation of cargo in a live cell model. Such upregulation of autophagy using small molecules is a promising approach for elimination of intracellular pathogens and neurodegenerative protein aggregates.
- Rajasekhar, Kolla,Narayanaswamy, Nagarjun,Mishra, Piyush,Suresh,Manjithaya, Ravi,Govindaraju
-
-
- Piperazines as model substrate for oxidations
-
Piperazine derivatives when being oxidized by mercury-EDTA behave unusually. Due to the reactive cyclic enediamine intermediates as aza-analogous reductones and to the carbonyl compounds resulting from dehydrogenation in the side chain, there exists a high tendency of polymerization. 1-Benzylpiperazines 5a-d generate the piperazine-2,3-diones 8a-d in medium yields. From 1-benzhydrylpiperazine 11 results a mixture of piperazine-2,3-dione 12 and piperazine-3-on 13. The 1,4-bis-substituted piperazines react more differently because of the symmetry and the preferred direction of the dehydrogenation into the cycle. Thus, from 15 and 19 the diones 16 and 20, respectively, were available in very good yields. A mechanism for the reactions is proposed.
- Moehrle,Azodi
-
p. 815 - 822
(2007/10/03)
-
- Piperazinone and piperazine polypeptides
-
Piperazinone polypeptides which are useful as analgesics and psychotherapeutic agents as well as processes to produce them are described.
- -
-
-