61341-05-7Relevant academic research and scientific papers
Iodine-Catalyzed Synthesis of Chiral 4-Imidazolidinones Using α-Amino Acid Derivatives via Dehydrogenative N-H/C(sp3)-H Coupling
Kanyiva, Kyalo Stephen,Tane, Marina,Shibata, Takanori
, p. 12773 - 12783 (2019/09/09)
An efficient method for the asymmetric synthesis of 4-imidazolidinones via an iodine-catalyzed intramolecular N-H/C(sp3)-H activation of readily available and abundant feedstocks, amino acids, and amines is described. The reaction proceeded under visible light irradiation to afford a variety of 4-imidazolidinone derivatives under mild conditions in moderate to excellent yields. Secondary and tertiary C(sp3)-H bonds were aminated, and various functional groups were tolerated.
Metal-Free N–H/C–H Coupling for Efficient Asymmetric Synthesis of Chiral Dihydroquinoxalinones from Readily Available α-Amino Acids
Kanyiva, Kyalo Stephen,Horiuchi, Masashi,Shibata, Takanori
supporting information, p. 1067 - 1070 (2018/03/06)
We have developed a method for the synthesis of dihydroquinoxalinones via intramolecular N–H/C–H coupling using hypervalent iodine. The starting materials were prepared from inexpensive and readily available aniline and amino acid derivatives. Various functional groups were tolerated to give multisubstituted dihydroquinoxalinones in moderate to excellent yields. The chirality of the amino acid was transferred to the desired target compound without a loss of enantiomeric excess. Preliminary mechanistic studies indicated that the reaction proceeds via an ionic mechanism.
Synthesis and structure of lower rim C-linked N-tosyl peptidocalix[4]arenes
Sdira, Sofiane Ben,Felix, Caroline P.,Giudicelli, Marie-Beatrice A.,Seigle-Ferrand, Pascal F.,Perrin, Monique,Lamartine, Roger J.
, p. 6632 - 6638 (2007/10/03)
Chiral p-tert-butylcalix[4]arenes functionalized at the lower rim with amino acid residues have been prepared. The 1H and 13C NMR spectra indicate that the macrocycles preferably adopt a cone conformation. Calix[4]arenes bearing amin
Synthesis and structural studies of new N-(p-toluenesulfonyl)amino acid o-phenolamides
Aguilar-Castro, Liliana,Tlahuextl, Margarita,Tapia-Benavides, Antonio R.,Tlahuext, Hugo
, p. 247 - 253 (2007/10/03)
The synthesis and structural studies of N-(p-Toluenesulfonyl)amino acid o-phenolamides was discussed. The structure and conformation of these amides were established by NMR spectroscopy and x-ray crystallography. Variable temperature experiments showed th
Effect of the 7-Amino Substituent on the Inhibitory Potency of Mechanism-Based Isocoumarin Inhibitors for Porcine Pancreatic and Human Neutrophil Elastases: A 1.85-Angstroem X-ray Structure of the Complex between Porcine Pancreatic Elastase and 7--4-chloro-...
Hernandez, Maria A.,Powers, James C.,Glinski, Jan,Oleksyszyn, Jozef,Vijayalakshmi, J.,Meyer, Edgar F.
, p. 1121 - 1129 (2007/10/02)
A series of new acyl, urea, and carbonate derivatives of 7-amino-4-chloro-3-methoxyisocoumarin were synthesized and evaluated as irreversible inhibitors of human neutrophil elastase (HNE) and porcine pancreatic elastase (PPE).Inhibition of HNE is directly related to the hydrophobicity of the substituent on the 7-amino group.The N-Tos-Phe derivative (19) is the best HNE inhibitor with a second-order rate constant kobs/ = 200 000 M-1s-1.The closest analogue in this series, the 3,3-diphenylpropionyl derivative 5, had kobs/ = 130 000 M-1s-1 with HNE.In contrast to the Tos-Phe derivative 19, phenylacetyl derivative 2 and carbonates 22 and 25 gave extremely stable enzyme-inhibitor complexes with deacylation half-lives longer than 48 h with both elastases.N-Phenylurea derivative 25 was the best inhibitor for PPE with a second-order rate constant kobs/ = 7300 M-1s-1.The crystal structure of a complex of PPE with N-tosyl-Phe derivative 19 was determined at 1.85 Angstroem resolution and refined to a final R factor of 16.9percent.The isocoumarin forms an acyl enzyme with Ser-195, while His-57 is near the inhibitor, but not covalently linked.The Tos-Phe makes a few hydrophobic contacts with the S' subsites of PPE, but appears to be interacting primarily with itself in the PPE structure.This region of HNE is more hydrophobic and modeling indicates that the inhibitor would probably make additional contacts with the enzyme.
