556-50-3Relevant articles and documents
THE PALLADIUM(II)-PROMOTED HYDROLYSIS OF METHYL AND ISOPROPYL GLYCYLGLYCINATE
Hay, Robert W.,Pujari, Mahesh P.
, p. 1083 - 1086 (1984)
The palladium(II)-promoted hydrolysis of methyl glycylglycinate and isopropyl glycylglycinate has been studied at four temperatures (25, 30, 35, and 40 deg C) at I=0.1 mol dm-3 in the pH range 4-5.Under these conditions, and at a 1:1 metal to ligand ratio, the peptide esters act as tridentate ligands, donation occuring via the terminal amino-group, the deprotonated amide nitrogen, and the carbonyl group of the ester.Rate constants are reported for hydrolysis of the ester function by water and hydroxide ion, and activation parameters calculated.Base hydrolysis of the co-ordinated peptide esters is ca. 1E5 times faster than the unproto nated peptide esters.Mechanisms for the reactions are considered.
Kotake,Saito
, p. 853 (1966)
Destrade et al.
, p. 2590,2593,2598 (1974)
En Route to a Heterogeneous Catalytic Direct Peptide Bond Formation by Zr-Based Metal-Organic Framework Catalysts
Conic, Dragan,De Azambuja, Francisco,Harvey, Jeremy N.,Loosen, Alexandra,Parac-Vogt, Tatjana N.,Van Den Besselaar, Maxime
, p. 7647 - 7658 (2021/06/30)
Peptide bond formation is a challenging, environmentally and economically demanding transformation. Catalysis is key to circumvent current bottlenecks. To date, many homogeneous catalysts able to provide synthetically useful methods have been developed, while heterogeneous catalysts remain largely restricted to the studies addressing the prebiotic formation of peptides. Here, the catalytic activity of Zr6-based metal-organic frameworks (Zr-MOFs) toward peptide bond formation is investigated using dipeptide cyclization as a model reaction. Unlike previous catalysts, Zr-MOFs largely tolerate water, and reactions are carried out under ambient conditions. Notably, the catalyst is recyclable and no additives to activate the COOH group are necessary, which are common limitations of previous methods. In addition, a broad reaction scope tolerates substrates with bulky and Lewis basic groups. The reaction mechanism was assessed by detailed mechanistic and computational studies and features a Lewis acid activation of carboxylate groups by Zr centers toward amine addition in which an alkoxy ligand on adjacent Zr sites assists in lowering the barrier of key proton transfers. The proposed concepts were also used to study the formation of intermolecular peptide bond formation. While intrinsic challenges associated with the catalyst structure and water removal limit a more general intermolecular reaction scope under current conditions, the results suggest that further design of Zr-MOF catalysts could render these materials broadly useful as heterogeneous catalysts for this challenging transformation.
Synthesis of Deuterated or Tritiated Glycine and Its Methyl Ester
Shevchenko,Andreeva,Nagaev, I. Yu.,Myasoedov
, p. 266 - 267 (2019/01/03)
Abstract: Heating glycine (Gly) and methyl glycinate (GlyOCH3) supported on 5% Pd/C or 5% Pt/C in a deuterium or tritium gas atmosphere gave the isotope-labeled products. The experiments were carried out at 180°C for 10 min. The deuterium atom inclusion under these conditions averaged up to 1.8 atoms per molecule for Gly and up to 1.0 atom per molecule for GlyOCH3. The reaction with tritium gas gave labeled products with a specific radioactivity of 27–31 Ci/mmol for Gly and 18 Ci/mmol for GlyOCH3.
