955-10-2Relevant articles and documents
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Vogl,Rondestvedt
, p. 3067,3068 (1955)
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Bulky Selenium Ligand Stabilized Trans-Palladium Dichloride Complexes as Catalyst for Silver-Free Decarboxylative Coupling of Coumarin-3-Carboxylic Acids
Bhuvanesh, Nattamai,Himanshi,Joshi, Hemant,Kumar, Anil,Kumar, Sunil,Meena, Neha,Reddy, S. Rajagopala,Shinde, Vikki N.
supporting information, (2022/01/11)
This report describes the syntheses of three new trans-palladium dichloride complexes of bulky selenium ligands. These complexes possess a Cl?Pd?Cl rotor spoke attached to a Se?Pd?Se axle. The new ligands and palladium complexes (C1?C3) were characterized with the help of NMR, HRMS, UV-Vis., IR, and elemental analysis. The single-crystal structure of metal complex C2 confirmed a square planar geometry of complex with trans-orientation. The X-ray structure revealed intramolecular secondary interactions (SeCH—Cl) between chlorine of PdCl2 and CH2 proton of selenium ligand. Variable-temperature NMR data shows coalescence of diastereotopic protons, which indicates pyramidal inversion of selenium atom at elevated temperature. The relaxed potential energy scan of C2 suggests a rotational barrier of ～12.5 kcal/mol for rotation of chlorine atom through Cl?Pd?Cl rotor. The complex C3 possesses dual intramolecular secondary interactions (OCH2—Cl and SeCH2—Cl) with stator ligand. Molecular rotor C2 was found to be a most efficient catalyst for the decarboxylative Heck-coupling under mild reaction conditions. The protocol is applicable to a broad range of substrates with large functional group tolerance and low catalyst loading (2.5 mol %). The mechanism of decarboxylative Heck-coupling reaction was investigated through experimental and computational studies. Importantly the reaction works under silver-free conditions which reduces the cost of overall protocol. Further, the catalyst also worked for decarboxylative arylation and decarboxylative Suzuki-Miyaura coupling reactions with good yields of the coupled products.
Looking for new xanthine oxidase inhibitors: 3-Phenylcoumarins versus 2-phenylbenzofurans
Borges, Fernanda,Delogu, Giovanna L.,Era, Benedetta,Fais, Antonella,Gatto, Gianluca,Kumar, Amit,Matos, Maria J.,Pintus, Francesca,Uriarte, Eugenio
, p. 774 - 780 (2020/07/07)
Overproduction of uric acid in the body leads to hyperuricemia, which is also closely related to gout. Uric acid production can be lowered by xanthine oxidase (XO) inhibitors. Inhibition of XO has also been proposed as a mechanism for improving cardiovascular health. Therefore, the search for new efficient XO inhibitors is an interesting topic in drug discovery. 3-Phenylcoumarins and 2-phenylbenzofurans are privileged scaffolds in medicinal chemistry. Their structural similarity makes them interesting molecules for a comparative study. Methoxy and nitro substituents were introduced in both scaffolds. The current study gives some insights into the synthesis and biological activity of these molecules against this important target. For the best compound of the series, the 3-(4-methoxyphenyl)-6-nitrocoumarin (4), the IC50 value, type of inhibition, cytotoxicity on B16F10 cells and ADME theoretical properties, were determined. Docking studies were also performed in order to better understand the interactions of this molecule with the XO binding pocket. This work is a preliminary screening for further design and synthesis of new non-purinergic derivatives as potential compounds involved in the inflammatory suppression, specially related to gout.
