2555-25-1Relevant articles and documents
Bulky Selenium Ligand Stabilized Trans-Palladium Dichloride Complexes as Catalyst for Silver-Free Decarboxylative Coupling of Coumarin-3-Carboxylic Acids
Meena, Neha,Kumar, Sunil,Shinde, Vikki N.,Reddy, S. Rajagopala,Himanshi,Bhuvanesh, Nattamai,Kumar, Anil,Joshi, Hemant
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.
Hydrolysis and substitution effects on the optical properties of coumarin derivatives studied by vibrational spectroscopy and DFT calculation
Khemakhem, Sirine,Elleuch, Slim,Ben Azaza, Najla,Ammar, Houcine,Abid, Younes
, p. 65 - 72 (2018/05/28)
A series of coumarin derivatives have been successfully synthesized. All compounds have been characterized by means of IR and Raman vibrational spectroscopic techniques at the solid state level. Optical absorption and photoluminescence measurements were p
Synthesis and in vitro evaluation of 3-(4-nitrophenyl)coumarin derivatives in tumor cell lines
Musa, Musiliyu A.,Latinwo, Lekan M.,Virgile, Clifford,Badisa, Veera L. D.,Gbadebo, Akintunde J.
, p. 96 - 103 (2015/02/19)
Coumarins are naturally-occurring compounds that have attracted considerable interest due to their numerous biological activities depending on their pattern of substitution on the coumarin molecule. In this present investigation, we synthesized 3-(4-nitro