Heterogeneous Brønsted Catalysis in the Solvent-Free and Multigram-Scale Synthesis of Polyalcohol Acrylates: The Case Study of Trimethylolpropane Triacrylate.

This article presents a thorough investigation into the synthesis of trimethylolpropane triacrylate (TMPTA) via the esterification reaction of trimethylolpropane (TMP) with acrylic acid using Amberlite™ 120 IR (H), Amberlyst 15, and Dowex™ 50WX8 resins as heterogeneous catalysts. Preliminary comparative tests explored the impact of air flow on water removal during the reaction and different acid-to-alcohol molar ratios (3:1, 6:1, or 9:1 mol:mol). The findings revealed that introducing air significantly enhances TMPTA yield and -OH group conversion, particularly at a 6:1 acid-to-alcohol molar ratio.

Impact of Hydrophobic Chains in Five-Coordinate Glucoconjugate Pt(II) Anticancer Agents.

This study describes new platinum(II) cationic five-coordinate complexes () of the formula [PtR(NHC)(dmphen)(ethene)]CFSO (dmphen = 2,9-dimethyl-1,10-phenanthroline), containing in their axial positions an alkyl group R (methyl or octyl) and an imidazole-based NHC-carbene ligand with a substituent R' of variable length (methyl or octyl) on one nitrogen atom. The Pt-carbene bond is stable both in DMSO and in aqueous solvents. In DMSO, a gradual substitution of dmphen and ethene is observed, with the formation of a square planar solvated species.

Sustainable Ketalization of Glycerol with Ethyl Levulinate Catalyzed by the Iron(III)-Based Metal-Organic Framework MIL-88A.

The catalytic properties of a simple iron-containing MOF based on fumaric acid, MIL-88A, were investigated in the ketalization of ethyl levulinate with glycerol. The corresponding product is a component of current interest as a renewable building block for many uses. Under the following conditions (solventless, 120 °C, stoichiometric ratio, 1% cat.

Halo complexes of gold(I) containing glycoconjugate carbene ligands: synthesis, characterization, cytotoxicity and interaction with proteins and DNA model systems.

New neutral carbene complexes of gold(I) [Au(Im-Me)X] (X = Cl, Au1; X = Br, Au2; X = I, Au3) have been synthesized and fully characterized by different techniques, including NMR and UV-vis absorption spectroscopy and single crystal X-ray diffraction. The carbene ligand Im-Me is decorated with a glucoside fragment a triazole linker, obtainable through a click chemistry reaction. The compounds retain the Au-NHC fragment in aqueous solvents, and an equilibrium between the neutral halo- and the cationic di-carbene form [Au(Im-Me)] is observed, whose extent follows the trend Au1 < Au2 < Au3.

Square-Planar vs. Trigonal Bipyramidal Geometry in Pt(II) Complexes Containing Triazole-Based Glucose Ligands as Potential Anticancer Agents.

This article describes the synthesis, characterization, and biological activity of novel square-planar cationic platinum(II) complexes containing glucoconjugated triazole ligands and a comparison with the results obtained from the corresponding five-coordinate complexes bearing the same triazole ligands. Stability in solution, reactivity with DNA and small molecules of the new compounds were evaluated by NMR, fluorescence, and UV-vis absorption spectroscopy, together with their cytotoxic action against pairs of immortalized and tumorigenic cell lines. The results show that the square-planar species exhibit greater stability than the corresponding five-coordinate ones.

Homogeneous Catalysis and Heterogeneous Recycling: A Simple Zn(II) Catalyst for Green Fatty Acid Esterification.

This work describes the use of simple zinc(II) salts (ZnCl, ZnCO, Zn(OAc), ZnO, Zn(ClO), Zn(TfO), and Zn(BF)) as effective catalysts for the esterification of fatty acids with long-chain alcohols and simple polyols through a homogeneous system that allows the gradual and selective removal of water. The results show that the catalytic activity depends on the nature of the counterion: the most effective are the salts with poorly coordinating anions (perchlorate and triflate) or containing basic Brønsted anions (oxide, acetate, and carbonate). However, only with the latter is it possible to fully recover the catalyst at the end of each run, which is easily filtered in the form of zinc carboxylate, given its insolubility in the ester produced.

Pt(II) versus Pt(IV) in Carbene Glycoconjugate Antitumor Agents: Minimal Structural Variations and Great Performance Changes.

Octahedral Pt(IV) complexes () containing a glycoconjugate carbene ligand were prepared and fully characterized. These complexes are structural analogues to the trigonal bipyramidal Pt(II) species () recently described. Thus, an unprecedented direct comparison between the biological properties of Pt compounds with different oxidation states and almost indistinguishable structural features was performed.

Iron(III) Complexes for Highly Efficient and Sustainable Ketalization of Glycerol: A Combined Experimental and Theoretical Study.

The growing production of biodiesel as a promising alternative and renewable fuel led as the main problem the dramatic increase of its by-product: glycerol. Different strategies for glycerol derivatization have been reported so far, some more efficient or sustainable than others. Herein, we report a very promising and eco-friendly transformation of glycerol in nontoxic solvents and chemicals (i.

A highly efficient and selective antitumor agent based on a glucoconjugated carbene platinum(ii) complex.

New five-coordinate Pt(ii) complexes containing a glycosylated carbene fragment were synthesized. A member of this class shows very high in vitro cytotoxicity and an exceptional selectivity toward malignant cells. The complex lacking the sugary portion fails in the recognition of cancer cells.

Reaction with Proteins of a Five-Coordinate Platinum(II) Compound.

Stable five-coordinate Pt(II) complexes have been highlighted as a promising and original platform for the development of new cytotoxic drugs. Their interaction with proteins has been scarcely studied. Here, the reactivity of the five-coordinate Pt(II) compound [Pt(I)(Me) (dmphen)(olefin)] (Me = methyl, dmphen = 2,9-dimethyl-1,10-phenanthroline, olefin = dimethylfumarate) with the model proteins hen egg white lysozyme (HEWL) and bovine pancreatic ribonuclease (RNase A) has been investigated by X-ray crystallography and electrospray ionization mass spectrometry.

Five-Coordinate Platinum(II) Compounds Containing Sugar Ligands: Synthesis, Characterization, Cytotoxic Activity, and Interaction with Biological Macromolecules.

This article describes the synthesis and characterization of novel cationic five-coordinate Pt(II) complexes containing nitrogen sugar-based ligands. The cytotoxicity of the complexes was evaluated on different cell lines with the expectation that both the coordinative saturation and the sugar moiety cooperate to enhance their biological activity. In fact, the complexes resulted to be more active than cisplatin but still with little selectivity.

Naphthalene-1,8-di-amine-2-(pyrimidin-2-yl)-1H-perimidine (2/1).

In the title adduct, C15H10N4·2C10H10N2, the pyrimidine ring is nearly co-planar with the heteroatomic perimidine ring, as indicated dihedral angle between their mean planes of 3.21 (11)°. The di-aminona-phthalene mol-ecules are slightly twisted [dihedral angles = 4.

Coordinated olefins as incipient carbocations: catalytic codimerization of ethylene and internal olefins by a dicationic Pt(II)-ethylene complex.

The coordinated ethylene molecule in the dicationic complex [(PNP)Pt(CH2=CH2)](BF4)2 (PNP = 2,6-bis(diphenylphosphinomethyl)pyridine) undergoes nucleophilic attack by free internal alkenes, giving the isolable complexes [(PNP)Pt(CH2=CHCH(Me)CMeRR'](BF4)2 (R, R' = H, Me) and providing a new effective pathway for a chemo- and regio-selective catalytic hydrovinylation reaction.