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In this study, we present the successful application of new and known stable 16‐electron ruthenium(II) pincer complexes POCOP, based on the naphthoresorcinate backbone, [Ru(X)(POCOP)(CO)] (X = H, Cl, Br, I, OCOCF3), in the catalytic alkylation of ketones and the coupling between amines and primary alcohols under mild conditions. These protocols demonstrated tolerance to a wide range of alcohols, ketones, and anilines, with reactions proceeding in high conversions and selectivity towards the hydrogenated ketones and the imines. The use of an excess of alcohol as the proton source facilitated the formation of the hydrogenated products. These results mark a significant advancement in the development of catalytic reactions with ruthenium POCOP pincer derivatives. [ABSTRACT FROM AUTHOR]

In this study, we report the synthesis of eight Schiff bases (3–10) type N-heterocycle (N-het) using conventional refluxing conditions as well as different eco-friendly techniques such as grinding, thermal fusion, microwave irradiation (MWI) and ultrasound, all of them in the presence of a catalytic amount of acetic acid. These procedures had the additional advantage of being environmentally friendly and high-yield, making these protocols an alternative for Schiff-base syntheses. The obtained Schiff bases were coordinated to palladium, generating new complexes of type [Pd2Cl4(N-het)2]. Complexes [Pd2Cl4(5)2] and [Pd2Cl4(9)2] showed high activity and selectivity for a model Mizoroki–Heck C-C coupling reaction of styrene with iodobenzene and bromobenzaldehydes. All compounds and complexes were evaluated for antifungal activity against clinically important fungi such as Candida albicans and Cryptococcus neoformans. Although the Schiff bases (3–10) showed low antifungal activity against both fungi, some of their palladium complexes such as [Pd2Cl4(3)2], [Pd2Cl4(5)2], [Pd2Cl4(8)2] and [Pd2Cl4(10)2] showed comparatively higher antifungal effects mainly against C. neoformans. The product of the Mizoroki–Heck-type C-C coupling reactions, 4-styrylbenzaldehyde, was isolated and purified to be later used in the synthesis of four new nitrophenylpyrazole derivatives of styrylimine, which also displayed antifungal activity, especially against C. neoformans. [ABSTRACT FROM AUTHOR]

In previous reports, it has been demonstrated that cyclometalated iron(II/III) complexes can be prepared by reacting iron(0) precursors and mercurated or brominated derivatives. However, in this report, the reaction between [Fe3(CO)12] and mercurated 6‐phenyl‐2,2′‐bipyridine or brominated 2,6‐diphenyl‐pyridine pincer derivatives led to compounds in which C(sp2)−C(sp2) bonds have been formed between two ligands. A 16‐electron iron(II) complex (1Cl) bearing a tetradentate ligand originating from the dimerization of 6‐phenyl‐2,2′‐bipyridine was isolated, while a protonated 14‐membered macrocycle with [FeBr4]− as counterion (2) was obtained from 2,6‐diphenyl‐pyridine. Studies by X‐ray diffraction crystallography, NMR, UV‐vis and cyclic voltammetry confirmed the structures. Additionally, the cytotoxicity of the new compounds toward gastric cancer cell lines was evaluated, and it was established that the presence of the iron(II) center was crucial for an elevated activity. [ABSTRACT FROM AUTHOR]

Intact photosensitive cyclometalated [Ru.sup.II] derivatives of 2-phenylpyridine or N,N-dimethylbenzylamine cis-[Ru-(C~N) (LL)[X.sub.2]] [PF.sub.6][C~N : o-[C.sub.6][H.sub.4]-py or o-[C.sub.6][H.sub.4]C[H.sub.2]N[Me.sub.2]; LL = 1,10-phenanththroline (phen), 2,2'-bipyridine (bpy), or 4,4'-[Me.sub.2]-2,2'-bipyridine ([Me.sub.2]bpy); X = MeCN or pyridine (py)] are efficient mediators of glucose oxidase (GO) from Aspergillus niger and horseradish peroxidase (HRP). Their redox potentials in an aqueous buffer are in the range 0.15-0.35 V versus SCE, and the rate constants for the oxidation GO(red) (where red indicates reduced) by the electrochemically generated [Ru.sup.III] species equal (1.7-2.5) x [10.sup.6] [M.sup.-1] [s.sup.-1] at pH 7 and 25[degrees]C. The redox potentials of all complexes decrease cathodically by 0.4-0.6 V upon irradiation by visible light because of the photoinduced solvolysis of acetonitrile or py ligands. These in situ generated species display an even better mediating performance with HRP, although their behavior toward GO is different. The loading of a ruthenium unit into the protein interior brings about large catalytic currents in a self-assembled system GO--Ru--D-glucose. The estimated rate constant for intramolecular electron transfer from FAD[H.sub.2] of the active site at [Ru.sup.III], [k.sub.intra], equals 4.4 x [10.sup.3] [s.sup.-1]]. This suggests that the distance between the redox partners is around 19 [Angstrom]. The value of 21 [Angstrom] was obtained through the docking analysis of a possible closest-to-FAD localization of a Ru-containing fragment derived from the irradiated complex cis-[Ru(o-[C.sub.6][H.sub.4]-py)-(phen) [(MeCN).sub.2]][PF.sub.6]. The operational stability of the GO-Ru assemblies depends on the nature of complex used, the highest being observed for cis-[Ru(o-[C.sub.6][H.sub.4]-py)([Me.sub.2]bpy)[(MeCN).sub.2]][PF.sub.6] (2). UV--vis studies of interaction of 2 with GO revealed photomechanical oscillations in the system GO--Ru--D-glucose. When irradiated complex 2 is mixed with GO and D-glucose, the absorbance at 510 nm increases because of the enzymatic reduction of [Ru.sup.III] to [Ru.sup.II]. The absorbance drops rapidly and then increases as in the first cycle after shaking the reaction solution. Many cycles are possible, and the rate of absorbance increase does not depend on a cycle number. A plausible mechanism of the oscillations is presented.

Research has been conducted on the family of cycloruthenated complexes. The synthesis of these complexes and the use of the cyclometalated compounds are discussed.

The [Os.sup.II] complex mediated reaction of C([sp.sup.2])-H bonds of 2-phenylpyridine and N,N-dimethylbenzylamine under mild condition which leads to the corresponding cyclometalated compounds in good to excellent yields is demonstrated. The newly obtained compounds could find applications in various fields including bioamperometric biosensors due their high activity as mediators of glucose oxidase.

Research has been conductedon osma(II)cycles. The authors report that these compounds have been produced via transmetalation using organomercurial in MeOH or via C-H bond cleavage of 2-phenylpyridine in MeCN.

Keywords: carbon-carbon coupling; cyclometalation; cytotoxicity; gastric cancer; iron; macrocyclic ligands EN carbon-carbon coupling cyclometalation cytotoxicity gastric cancer iron macrocyclic ligands 1 1 1 08/16/23 20230811 NES 230811 B The Front Cover b shows a representation of stomach cancer cells being destroyed by an iron(II) complex bearing a tetradentate ligand. Front Cover: Synthesis of Cytotoxic Iron-Containing Macrocycles Through Unexpected C(sp2)-C(sp2) Bonds Formation (Eur. J. Inorg. Carbon-carbon coupling, cyclometalation, cytotoxicity, gastric cancer, iron, macrocyclic ligands. [Extracted from the article]