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1.
1,3-Dialkylimidazolium-2-carboxylate compounds have recently been fully characterised. Here we describe the utilisation of 1,3-dimethyl (1a) and 1-butyl-3-methyl-imidazolium-2-carboxylate (1b) in a carboxylation reaction with transfer of the CO2 moiety to benzoylacetone and methanol for the synthesis, in high yield, of benzoylacetate and monoalkylcarbonate anions, respectively. Conversely, when compounds 1a and b are reacted with carbonylic substrates lacking C-H active bonds, a product resulting from nucleophilic attack of the 1,3-dialkylimidazol-2-ylidene species on the carbonyl moiety is obtained. The reported reactions can find applications in organic synthesis and in the synthesis of halogen-free ionic liquids. 相似文献
2.
Aresta M Tommasi I Quaranta E Fragale C Mascetti J Tranquille M Galan F Fouassier M 《Inorganic chemistry》1996,35(14):4254-4260
Extended labeling experiments have shown that formation of rhodium peroxocarbonate from CO(2) and [RhCl(eta(2)-O(2))(P)(3)] (P is PEt(2)Ph or PEtPh(2)) proceeds through O-O bond cleavage and CO(2) insertion. O-transfer to ancillary phosphine ligand to give R(3)P=O selectively (>85%) involves the Rh-linked O atom of the peroxo group of RhCl(CO(4))(P)(3). 相似文献
3.
Fabiana Quaglia Giuseppe Fusco Giuseppe De Rosa Francesca Ungaro Agnese Miro Maria Immacolata La Rotonda 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):669-674
The aim of this work was to produce lycopene-containing powders from tomato products by a solvent-free method making use of
β-cyclodextrin (βCD). Powders were prepared by spray-drying a tomato concentrate (TC), one of the most bioavailable form of
lycopene, after mechanical treatment with βCD in different weight ratios. The obtained product was centrifuged to eliminate
partly food matrix and characterized for the amount of lycopene hydrodispersed/hydrosolubilized in the aqueous fraction. The
chemical antioxidant activity of sera was evaluated too. Powders obtained by spray-drying sera exhibited good flow properties,
a lycopene content between 0.4 and 1.09 mg/g and excellent water dispersability. The process developed, which makes use of
βCD for the treatment of tomato products, turns to be of great interest to obtain a bulk material for nutraceuticals displaying
superior biovailability of lycopene. 相似文献
4.
Immacolata Faraone Fabiana Labanca Maria Ponticelli Nunziatina De Tommasi Luigi Milella 《Molecules (Basel, Switzerland)》2020,25(22)
The rapid spread of the new Coronavirus Disease 2019 (COVID-19) has actually become the newest challenge for the healthcare system since, to date, there is not an effective treatment. Among all drugs tested, Hydroxychloroquine (HCQ) has attracted significant attention. This systematic review aims to analyze preclinical and clinical studies on HCQ potential use in viral infection and chronic diseases. A systematic search of Scopus and PubMed databases was performed to identify clinical and preclinical studies on this argument; 2463 papers were identified and 133 studies were included. Regarding HCQ activity against COVID-19, it was noticed that despite the first data were promising, the latest outcomes highlighted the ineffectiveness of HCQ in the treatment of viral infection. Several trials have seen that HCQ administration did not improve severe illness and did not prevent the infection outbreak after virus exposure. By contrast, HCQ arises as a first-line treatment in managing autoimmune diseases such as rheumatoid arthritis, lupus erythematosus, and Sjögren syndrome. It also improves glucose and lipid homeostasis and reveals significant antibacterial activity. 相似文献
5.
Immacolata Speciale Flaviana Di Lorenzo Valentina Gargiulo Gitte Erbs Mari‐Anne Newman Antonio Molinaro Cristina De Castro 《Angewandte Chemie (International ed. in English)》2020,59(16):6368-6374
The lipopolysaccharide (LPS) O‐antigen structure of the plant pathogen Rhizobium radiobacter strain TT9 and its possible role in a plant‐microbe interaction was investigated. The analyses disclosed the presence of two O‐antigens, named Poly1 and Poly2. The repetitive unit of Poly2 constitutes a 4‐α‐l ‐rhamnose linked to a 3‐α‐d ‐fucose residue. Surprisingly, Poly1 turned out to be a novel type of biopolymer in which the repeating unit is formed by a monosaccharide and an amino‐acid derivative, so that the polymer has alternating glycosidic and amidic bonds joining the two units: 4‐amino‐4‐deoxy‐3‐O‐methyl‐d ‐fucose and (2′R,3′R,4′S)‐N‐methyl‐3′,4′‐dihydroxy‐3′‐methyl‐5′‐oxoproline). Differently from the O‐antigens of LPSs from other pathogenic Gram‐negative bacteria, these two O‐antigens do not activate the oxidative burst, an early innate immune response in the model plant Arabidopsis thaliana, explaining at least in part the ability of this R. radiobacter strain to avoid host defenses during a plant infection process. 相似文献
6.
7.
1,3-Dialkylimidazolium-2-carboxylate compounds of formulas 1a, 2, and 4 have been synthesized and fully characterized by X-ray spectroscopy quite recently. Up today, these compounds have found some interesting applications as precursors of N-heterocyclic carbenes (NHCs) used as ligands for metal-complexes or in the synthesis of organic compounds and ionic liquids. We have recently reported the use of 1-butyl, 3-methylimidazolium-2-carboxylate and 1,3-dimethylimidazolium-2-carboxylate in a CO2-transfer reaction to CH3OH and acetophenone for the synthesis of methylcarbonate and benzoylacetate. The scope of this CO2-transfer reaction has been expanded to several organic compounds with active hydrogen (acetone, cyclohexanone, and benzylcyanide) for the synthesis of carboxylates of pharmaceutical interest, and to propargyl alcohols for the synthesis of α-alkylidene cyclic carbonates. 相似文献
8.
1,3-Dialkylimidazolium-2-carboxylates 1a and 1b are obtained in good to excellent yield and selectivity by carboxylation of the corresponding 1,3-dialkylimidazolium chloride salts with a CO2/Na2CO3 system at temperatures ranging from 80 to 135 °C. The effect of temperature and reaction time on the yield and the selectivity of the carboxylation products has been studied. Coupling the CO2-based synthesis of 1,3-dialkylimidazolium-2-carboxylates with the transcarboxylation reaction described earlier [Tommasi, I.; Sorrentino, F.; Tetrahedron Lett., 2005, 46, 2141] allows us to set up a new synthetic procedure for the synthesis of organic carboxylates and alkylcarbonate anions avoiding the use of strong bases. 相似文献
9.
Naphthalene catalyzed lithiation of 1,3-dimethyl-2-phenylimidazolidine led to cleavage of the benzylic carbon-nitrogen bond, with formation of an intermediate dianion. Under similar conditions, 1,3-dimethyl-2-(4-chlorophenyl)imidazolidine underwent regioselective cleavage of the aromatic carbon-chlorine bond, leading to a 4-formylphenyllithium equivalent, whilst 1,3-dimethyl-2-(4-methoxymethylphenyl)imidazolidine underwent regioselective cleavage of the benzylic carbon-oxygen bond, leading to a 4-formylbenzyllithium equivalent. 相似文献
10.
Francesco Barbato Maria Immacolata La Rotonda Agnese Miro Patrizia Morrica Fabiana Quaglia 《Journal of inclusion phenomena and macrocyclic chemistry》2000,38(1-4):423-433
This study was carried out with the aim ofinvestigating the interactions between-cyclodextrin and carbaryl, a carbamatepesticide, and their effect on some physico-chemicalproperties of carbaryl, such as aqueous solubility andlipophilicity. The interactions between carbaryl and-cyclodextrin were thoroughly investigated bothin solution and in the solid state. The effect of-cyclodextrin on the aqueous solubility ofcarbaryl was evaluated by the phase solubility method.The amount of carbaryl dissolved increased linearlywith the addition of -cyclodextrin according toan AL type plot and without precipitation of thecomplex. The apparent stability constant of thecomplex was 289 ± 21 M-1, assuming a 1 : 1stoichiometry; this value was confirmed by a methodbased on circular dichroism measurements.Equimolar carbaryl/-cyclodextrin solid systemswere prepared by physical-mixing and freeze-drying,and fully characterised by Differential ScanningCalorimetry, X-ray powder diffractometry and FourierTransform Infra-Red analysis. The results of the solidstate study demonstrated that the freeze-drying methodyields a system with a high degree of amorphisationand yields an inclusion complex.The dissolution profile of the pesticide was affectedby the physico-chemical properties of each solidsystem, the freeze-dried form dissolving more rapidly. However, the physical association of-cyclodextrin and carbaryl enhanced the aqueoussolubility of the insecticide as well. 相似文献