The increase of noble-metal-free catalysis in organic chemistry is a trending topic in constant growth due to the price increase of noble metals and their scarce abundance. As a result, many earth-abundant transition-metal complexes containing nickel, iron, or cobalt have been successfully applied in the homogeneous catalysis of a wide number of cross-coupling reactions, and the use of pincer complexes based on these earth-abundant metals was recently explored, affording interesting results. Thus, this review provides a general overview of earth-abundant 3D pincer complexes and their application during the last decade as catalysts in cross-coupling reactions such as Kumada–Corriu, Suzuki–Miyaura, Sonogashira, C–S cross-coupling, and C–N bond-forming reactions.

A series of three Ni(II)‐POCOP complexes para‐functionalized with an acetoxyl fragment were synthesized. All complexes (2 a–c) were fully characterized through standard analytical techniques. The molecular structure of complex 2 b was unambiguously determined by single‐crystal X‐ray diffraction, revealing that the metal center is situated in a slightly distorted square‐planar environment. Additionally, the acetoxy fragment at the para‐position of the phenyl ring was found to be present. The in vitro cytotoxic activity of all complexes was assessed on six human cancer cell lines. Notably, complex 2 b exhibited selective activity against K‐562 (chronic myelogenous leukemia) and MCF‐7 (mammary adenocarcinoma) with IC₅₀ values of 7.32±0.60 μM and 14.36±0.02 μM, respectively. Furthermore, this compound showed negligible activity on the healthy cell line COS‐7, highlighting the potential therapeutic application of 2 b. The cytotoxic evaluations were further complemented with molecular docking calculations to explore the potential biological targets of complex 2 b, revealing interactions with cluster differentiation protein 1a (CD1 A, PDB: 1xz0) for K‐562 and with the progesterone receptor for MCF‐7.

The application of organometallic materials as anodes in fuel cell devices has experienced a notable increase in recent years. However, the use of POCOP pincer complexes remains scarcely explored despite their great relevance in catalysis. Thus, in this work, the electrocatalytic activity to methanol in alkaline media of three Ni(II)-based POCOP pincer complexes—[NiCl{C₆H₂-4-OH-2,6-(OPiPr₂)₂}] (a1), [NiCl{C₆H₂-4-OH-2,6-(OPtBu₂)₂}] (a2), and [NiCl{C₆H₂-4-OH-2,6-(OPPh₂)₂}] (a3)—will be discussed. The complexes were use as modifiers of carbon paste electrodes that were evaluated using cyclic voltammetry considering diverse factors, such as the absence and presence of MeOH, diverse proportions (% w/w) of the complex in the electrode, scan rate, and different MeOH concentrations. Results indicated the presence of a redox pair Ni(II)/Ni(III) with a quasi-reversible behavior in all complexes, the anodic peak currents of which were proportional to the increase in MeOH concentrations (0.05–0.3 mM), and their oxidation potentials varied in the function of the P-substituent in the Ni(II)-POCOPs backbone. Complex a1 exhibited the best current density (429.5 mA cm² at 0.5 mM) compared to its analogs a2 and a3. The current intensity of all electrodes displays good stability, which remains—with slight changes—up to 100 s. Moreover, a comparison of their catalytic rate constants suggested a great activity in complex a1 (0.52 × 10⁶ cm³ mol⁻¹ s⁻¹) compared to its analogues, implying a great activity in the electro-oxidation of MeOH. Hence, this work opens new opportunities for the electrochemical application of POCOPs complexes for future DMFCs development.

Identification of a new class of antitumor agent capable to induce apoptosis without triggering necrotic cell death event is challenging. The present communication describes the multicomponent synthesis of seven new (1S,4S)-2,5-diazabicyclo[2.2.1]heptane-dithiocarbamates and their in vitro antiproliferative activity on cervical cancer cell line (CaSki), breast cancer cell line (MDA-MB231), lung cancer cell line (SK-Lu-1) and human lymphocytes. Among the synthesized dithiocarbamates, compound 9e displayed significant antiproliferative activity without inducing any necrotic cell death (both on tumour cells and lymphocytes) and induced apoptosis in tumor cells by the caspase dependent apoptotic pathway. The compound 9e also exhibited greater tumor selectivity than human lymphocytes. In silico ADME predictions revealed that compound 9e has the potential to be developed as a drug candidate. Rapid chemical modifications of this lead are thus highly necessary for further investigation as a drug like safer antitumor candidate and also to achieve compounds with better activity profile.

The synthesis of three novel curcumin derivative compounds, featuring aza‐crown ether macrocycles of various sizes (aza‐12‐crown‐4, aza‐15‐crown‐5, and aza‐18‐crown‐6), is described. The incorporation of these aza‐crown macrocycles significantly enhances their water solubility, positioning them as groundbreaking instances of curcumin derivatives that are fully soluble in aqueous environments. These curcumin ligands (L1, L2, and L3) were then reacted with zinc acetate to afford the coordination metal complexes (L1‐Zn, L2‐Zn, and L3‐Zn). Comprehensive characterization of all compounds was achieved using various analytical techniques, including 1D and 2D NMR spectroscopy, ATR‐FTIR spectroscopy, mass spectrometry (ESI⁺), elemental analysis and UV‐Vis spectroscopy. The in vitro cytotoxic activity of both, ligands and complexes were evaluated on three human cancer cell lines (U‐251, MCF‐7, and SK‐LU‐1). Compared to conventional curcumin, these compounds demonstrated improved antiproliferative potential. Additionally, a wound healing assay was conducted to assess their antimigration properties. The obtained results suggest that these modifications to the curcumin structure represent a promising approach for developing therapeutic agents with enhanced cytotoxic properties.