The Recent Advances in Iron-Catalyzed C(sp3 )-H Functionalization.

The use of iron as a core metal in catalysis has become a research topic of interest over the last few decades. The reasons are clear. Iron is the most abundant transition metal on Earth's crust and it is widely distributed across the world. It has been extracted and processed since the dawn of civilization. All these features render iron a noncontaminant, biocompatible, nontoxic, and inexpensive metal and therefore it constitutes the perfect candidate to replace noble metals (rhodium, palladium, platinum, iridium, etc.). Moreover, direct C-H functionalization is one of the most efficient strategies by which to introduce new functional groups into small organic molecules. The majority of organic compounds contain C(sp3 )-H bonds. Given the enormous importance of organic molecules in so many aspects of existence, the utilization and bioactivity of C(sp3 )-H bonds are of the utmost importance. This review sheds light on the substrate scope, selectivity, benefits, and limitations of iron catalysts for direct C(sp3 )-H bond activations. An overview of the use of iron catalysis in C(sp3 )-H activation protocols is summarized herein up to 2022.

Structural elucidation, theoretical investigation, biological screening and molecular docking studies of metal(II) complexes of NN donor ligand derived from 4-(2-aminopyridin-3-methylene)aminobenzoic acid.

Complexes of 4-(((2-aminopyridin-3-yl)methylene)amino)benzoic acid ligand with cobalt(II) (1), nickel(II) (2), copper(II) (3), zinc(II) (4) and palladium(II) (5) are synthesized and characterized by using different spectroscopic methods like, UV-Visible, infrared, 1H, 13C NMR, molar conductance, ESR and elemental analysis. Quantum chemical computations were made using DFT (density functional theory), B3LYP functional and 6-31+ +G(d,p)/SDD basis set in order to determine optimized structure parameters, frontier molecular orbital parameters and NLO properties. Based on DFT and experimental evidence, the complexes ensured that the octahedral geometry have been proposed for complexes 1, 2 and 4, square planar for complexes 3 and 5. All the complexes showed only residual molar conductance values and hence they were considered as non-electrolytes in DMF. In addition, the anti-proliferative activity of the compounds was evaluated against different human cancer cell lines (IMR-32, MCF-7, COLO205, A549, HeLa and HEK 293) and cisplatin is used as a reference drug. Compounds 1 and 4 showed remarkable cytotoxicity in five cancer cell lines tested except MCF-7. Also, the compounds were examined for their in vitro antimicrobial and scavenging activities. The molecular docking results are well corroborated with the experimental anticancer activity results.

Synthesis, characterization, theoretical, molecular docking and in vitro biological activity studies of Ru(II) (η6-p-cymene) complexes with novel aniline substituted aroyl selenoureas.

A sequence of aroyl selenourea ligands (L1-L3) substituted by aniline and their Ru(II) (η6-p-cymene) complexes (1-3), [Ru(II) (η6-p-cymene) L] (L = monodentate aroyl selenourea ligand) have been synthesized and characterized the composition of the ligands and their metal complexes. The molecular structures of ligand L1 and complex 3 were also confirmed by single XRD crystal method. The single-crystal XRD study showed that aroyl selenourea ligand coordinates with Ru via Se novel neutral monodentate atom. In vitro DNA interaction studies were investigated by Fluorescence and UV-Visible spectroscopic methods which showed that the intercalative mode of binding is in the order of 1 > 2 > 3 with Ru(II) (η6-p-cymene) complexes. Spectroscopic methods have been used for measuring the binding affinity of bovine serum albumin to complex. Moreover, the cytotoxic study of complexes (1-3) were evaluated against HeLa S3, A549, and IMR90 cells, resulting in complexes 1 and 2 showed promising cytotoxic activity against HeLa S3 cell with IC50 values of 24 and 26 µM, respectively. Also, the morphological changes of HeLa S3 and A549 cells were confirmed by fluorescence microscope in the presence of complexes 1 and 2 using AO (acridine orange, 200 µM) and EB (ethidium bromide, 100 µM). In addition, the docking results strongly support the protein binding studies of the complexes.Communicated by Ramaswamy H. Sarma.

Synthesis and Anticancer Activity of [RuCl2(η6-arene)(aroylthiourea)] Complexes-High Activity against the Human Neuroblastoma (IMR-32) Cancer Cell Line.

Eight new organometallic Ru(II)-arene complexes of the type [RuCl2(η6-arene)(η1-S-aroylthiourea)] (arene = p-cymene or benzene) were synthesized in order to evaluate the effect of the arene moiety and the substituent of the aroylthiourea ligand on the cytotoxicity of the complexes. The ligands (L1 and L2) and complexes (1-8) were characterized using analytical and spectroscopic (UV-visible, infrared, 1H NMR, 13C NMR, and mass) methods. The structure of the ligands (L1 and L2) and complexes (1 and 3-6) was obtained from single-crystal X-ray diffraction studies. The cytotoxicity of the complexes was evaluated against four different cancer cell lines: MCF-7 (breast), COLO 205 (colon), A549 (lung), and IMR-32 (neuroblastoma). All the complexes showed good cytotoxicity and the highest was in the IMR-32 cell line, which articulates the specificity of these complexes toward the IMR-32 cancer cell line. The complexes 5, 7, and 8 exhibited remarkable cytotoxicity in the entire cancer cell lines tested, which was comparable with the standard drug, cisplatin. The anticancer mechanism of the complexes 3 and 7 in IMR-32 cells was evaluated by bright-field microscopy, intracellular reactive oxygen species (ROS), mitochondrial membrane potential (MMP), DNA damage, and caspase-3 analyses. The cells treated with the complexes showed upregulated caspase-3 compared to the control, and it was found that ROS and MMP were dose-dependent on analysis. Also, bright-field microscopy and 4',6-diamidino-2-phenylindole (DAPI) staining have correspondingly shown cellular membrane blebbing and DNA damage, which were morphological hallmarks of apoptosis. The study concluded that the complexes promoted the oxidative stress-mediated apoptotic death of the cancer cells through the generation of intracellular ROS, depletion of MMP, and damage of the nuclear material.