10.1016/j.ica.2009.12.033
The research aims to synthesize and characterize a series of rhodium(III) complexes containing the 1,2-naphthoquinone-1-oxime (1-nqo) ligand and different pyridine-type co-ligands (4-methylpyridine, 4-phenylpyridine, and 4-acetylpyridine). The purpose is to investigate their electronic transition behaviors and electrochemical properties. The study employs various characterization techniques, including single crystal X-ray crystallography, mass spectrometry, 1H–1H COSY NMR, FT-IR, UV–Vis absorption spectroscopy, and cyclic voltammetry, as well as theoretical calculations using DFT and TD-DFT methods. The key findings include the identification of metal to 1-nqo ligand charge transfer (MLCT) and chloride to 1-nqo ligand charge transfer (LLCT) transitions in the UV–Vis spectra, and the observation of irreversible, metal-localized two-electron reductions in the cyclic voltammograms. The research concludes that the electronic properties of these complexes are influenced by the nature of the pyridine-type co-ligands, with changes in their electron-donating ability affecting the energy levels of the triplet orbitals and the reductive potentials of the complexes.
10.1021/acs.orglett.0c02635
The study presents the development of a catalytic system for the C-alkylation of N-heterocyclic compounds, such as pyridine, pyrimidine, pyrazine, quinoline, quinoxaline, and isoquinoline, using alcohols. The process is based on a hydrogen-borrowing approach and utilizes [Cp*IrCl2]2 as the catalyst precursor, combined with potassium t-butoxide and 18-crown-6-ether. This method is environmentally friendly as it only produces water as a byproduct. The researchers optimized the reaction conditions and demonstrated the system's versatility by applying it to various substrates, achieving good to excellent yields. The study also proposed a possible reaction mechanism involving three steps: hydrogen transfer from alcohol to iridium catalyst, cross-aldol-type condensation, and transfer hydrogenation. The developed catalytic system is expected to contribute to the synthesis of pharmaceuticals and functional materials.
T
