Green procedure for one-pot synthesis of azelaic acid derivatives using metal catalysis

Background & Objective: A green one-pot synthesis of oleic acid (1) derivatives is promoted by Rare Earth Metal (REM) triflates and commercial Molybdenum dioxo dichloride (MoCl 2 O 2 ) in the presence hydrogen peroxide as a green oxidant. Results: The protocol permits to govern the oxidation selectivity by simply choosing the proper combination of Mo and Sc catalysts. Conclusion: Methyl oleate epoxide 2a and azelaic acid 6 thus obtained are valuable industrial intermediates for synthesizing bio-compostable plastics, plasticizers of PVC, lubricating oils, cosmetics and pharmaceuticals (bactericides, anti-inflammatories, etc.)

Partial Hydrogenation of Soybean and Waste Cooking Oil Biodiesel over Recyclable-Polymer-Supported Pd and Ni Nanoparticles

Biodiesel obtained through the transesterification in methanol of vegetable oils, such as soybean oil (SO) and waste cooking oil (WCO), cannot be used as a biofuel for automotive applications due to the presence of polyunsaturated fatty esters, which have a detrimental effect on oxidation stability (OS). A method of upgrading this material is the catalytic partial hydrogenation of the fatty acid methyl ester (FAME) mixture. The target molecule of the partial hydrogenation reaction is monounsaturated methyl oleate (C18:1), which represents a good compromise between OS and the cold filter plugging point (CFPP) value, which becomes too high if the biodiesel consists of unsaturated fatty esters only. In the present work, polymer-supported palladium (Pd-pol) and nickel (Ni-pol) nanoparticles were separately tested as catalysts for upgrading SO and WCO biodiesels under mild conditions (room temperature for Pd-pol and T = 100 °C for Ni-pol) using dihydrogen (p = 10 bar) as the reductant. Both catalysts were obtained through co-polymerization of the metal containing monomer M(AAEMA)2 (M = Pd, Ni; AEEMA− = deprotonated form of 2-(acetoacetoxy)ethyl methacrylate)) with co-monomers (ethyl methacrylate for Pd and N,N-dimethylacrilamide for Ni) and cross-linkers (ethylene glycol dimethacrylate for Pd and N,N’-methylene bis-acrylamide for Ni), followed by reduction. The Pd-pol system became very active in the hydrogenation of C=C double bonds, but poorly selective towards the desirable C18:1 product. The Ni-pol catalyst was less active than Pd-pol, but very selective towards the mono-unsaturated product. Recyclability tests demonstrated that the Ni-based system retained its activity and selectivity with both the SO and WCO substrates for at least five subsequent runs, thus representing an opportunity for waste biomass valorization

Metal-based Heterogeneous Catalysts for One-Pot Synthesis of Secondary Anilines from Nitroarenes and Aldehydes

Recently, N-substituted anilines have been the object of increasing research interest in the field of organic chemistry due to their role as key intermediates for the synthesis of important compounds such as polymers, dyes, drugs, agrochemicals and pharmaceutical products. Among the various methods reported in literature for the formation of C–N bonds to access secondary anilines, the one-pot reductive amination of aldehydes with nitroarenes is the most interesting procedure, because it allows to obtain diverse N-substituted aryl amines by simple reduction of nitro compounds followed by condensation with aldehydes and subsequent reduction of the imine intermediates. These kinds of tandem reactions are generally catalyzed by transition metal-based catalysts, mainly potentially reusable metal nanoparticles. The rapid growth in the last years in the field of metal-based heterogeneous catalysts for the one-pot reductive amination of aldehydes with nitroarenes demands for a review on the state of the art with a special emphasis on the different kinds of metals used as catalysts and their recyclability features

Copper(II) chloride-catalysed oxidative carbonylation of glycerol to glycerol carbonate

A systematic study on copper(II) as catalyst for the synthesis of glycerol carbonate via oxidative carbonylation is here reported for the first time. Copper(II) chloride has been found to efficiently promote the process under homogeneous conditions treating glycerol with CO:O2 (Ptot = 4 MPa; P(O2) = 0.7 MPa), in DMA at 130 ◦C and in the presence of pyridine as co-catalyst. Excellent conversions (>92%) and selectivities (>93%) are obtained in relatively short reaction times (3–4 h) also with copper(II) complexes. The catalyst overall TON is evaluated and new experimental evidences are provided allowing significant advancements in the mechanism comprehension

Photoactivated aqueous nanocolloids of Platicur: NMR metabolomic study of treated HeLa cancer cells

Platicur is a cis-diamine-platinum(II) complex linked to curcumin. Previous studies have shown that the photoactivation of Platicur, with visible light, is responsible for the production of active species of platinum(II) and a photoactive curcumin. The active species formed act synergistically causing an interesting anticancer activity. In this work, we tried to improve the antitumor activity of photoactivated Platicur by using a nano delivery system. With this aim, Platicur's aqueous chitosan nanocolloids were synthesized, Figure 1. The preliminary in vitro biological assays on HeLa tumor cell line have demonstrated a significantly higher cytotoxicity (a significantly lower IC50 dose) of the photoactivated nanocolloids with Platicur, compared to the photoactivated Platicur not encapsulated in the nanocolloids. The use of a metabolomic approach based on NMR spectroscopy in the research of the mechanism of action or for the evaluation of the tumor response to the anticancer metal drugs is a new tool of recent growth. The side effects induced by metal based drugs, the prediction of the response to treatment and the key information on the mechanism of action (for known and new compounds) could be easily obtained using NMR-based metabolomics. [2, 3] For this reason, the 1H NMR spectroscopy coupled with multivariate statistical analysis was used to characterize the metabolic variations of intracellular metabolites and the compositional changes of the corresponding culture media of HeLa cells treated with photoactivated Platicur nanocolloids. The metabolomic analysis allowed to highlight specific metabolic differences between the cells treated with photoactivated Platicur nanocoloids compared to non-photoactivated ones. The NMR has once again proved to be a valid tool for the study of the mechanism of action of metal-based drugs