Monica Nardi

Highly efficient and versatile acetylation of alcohols catalyzed by cerium(III) triflate

Cerium(III) triflate is a powerful catalyst for the acetylation of alcohols. The reaction works well for a large variety of simple and functionalized alcohols, without isomerisation of chiral centres. Changes of hydroxyl protective groups are possible in a one-pot procedure. The catalyst can be easily recycled.

Synthesis, biological evaluation, and molecular modeling of oleuropein and its semisynthetic derivatives as cyclooxygenase inhibitors.

Oleuropein, the main phenolic compound in virgin olive oil, and several of its derivatives such as oleuropein aglycone, hydroxytyrosol, and their respective acetylated lipophilic forms were obtained by simple and environmentally friendly semisynthetic protocols. The same molecules were then tested in vitro and in vivo, comparing their intriguing anti-COX-1 and anti-COX-2 properties to those of well-known anti-inflammatory drugs such as ibuprofen and celecoxib. Finally, molecular modeling experiments displaying the most probable binding modes within the classical binding clefts of the enzymes suggest the heme moiety as a potential alternative target.

A Mesoporous ErIII‐MCM‐41 Catalyst for the Cyanosilylation of Aldehydes and Ketones under Solvent‐free Conditions

To perform organic reactions without solvents is one of the most important challenges for organic chemists from both an economic and environmental standpoint because it would reduce environmental pollution and bring down handling costs owing to simplification of experimental procedures and workup techniques. Solvent-free reactions may be carried out by using the reactants alone or by incorporating them in clays, zeolites, silica, alumina or other matrices. Moreover, the development of active and environmentally friendly solid catalysts is also a priority with respect to green chemistry. Such catalysts offer several advantages such as good selectivity, easy separation and the possibility to be recovered and reused. In recent years, Er salts have been employed as efficient and non-toxic Lewis acid catalysts in several organic transformations. Among the plethora of lanthanide ions, Er is one of the most efficient Lewis acids in terms of the values of its hydrolysis constant (Kh) and water-exchange rate constants [6]

Per-O-acetylation of sugars catalyzed by Ce(OTf)3

Ce(OTf)3 is proposed as a valuable Lewis acid promoter in the per-O-acetylation reactions of sugars. The Ce(OTf)3 is an environmentally friendly catalyst, used in very low percentage, and can be recovered after reaction and used without significant loss of activity.

High-Throughput Assay of Oleopentanedialdheydes in Extra Virgin Olive Oil by the UHPLC-ESI-MS/MS and Isotope Dilution Methods

The quality of extra virgin olive oil is associated with the presence of microcomponents whose healing effects have been proved in some special cases. The enzymatic hydrolysis of oleuropein and ligstroside, and of their demethylated analogues, affords four different pentanedialdehydes, and for one of which, 2-(4-hydroxyphenyl)ethyl (3S,4E)-4-formyl-3-(2-oxoethyl)hex-4-enoate, also known as oleocanthal, an anti-inflammatory effect was quite recently carefully assessed. Extra virgin olive oil is now worldwide considered as a functional food whose daily intake, as for the Mediterranean diet, helps consumers in keeping a constant level of nonsteroidal anti-inflammatory drug (NSAID) in the blood. The presence of these active principles provides, therefore, olive oil with an important added value. In the framework of the actions of the recently funded Agrifood Regional Center, which should coordinate the scientific research and production worlds, an absolute analytical method was developed for the mass spectrometric detection of the two most abundant NSAIDs, Tyr-OLPD and HTyr-OLPD (oleopentanedialdehydes (OLPDs) conjugated to p-hydroxyphenylethanol and 3,4-dihydroxyphenylethanol, respectively), by UHPLC-ESI-MS/MS.

Mild and efficient method for the cleavage of benzylidene acetals by using erbium (III) triflate

Er(OTf)3 is proposed as new efficient Lewis acid catalyst in a mild deprotection protocol of benzylidene derivatives. In a modified procedure, where acetic anhydride is used as the reaction solvent, the simultaneous cleavage of the benzylidene acetal and the peracetylation of the substrates is obtained in quantitative yields and very short reaction times.

Aqueous MW eco-friendly protocol for amino group protection

In this paper a new catalyst-free and on-water method for protection of amines and amino acids with di-tert-butyl dicarbonate, 9-fluorenylmethoxycarbonyl chloride, acetyl chloride and tosyl chloride is presented. The protection can be realized in a few minutes under microwave-assistance. The reaction proved to be chemoselective in presence of ambident nucleophiles and water solution of di-tert-butyl carboxylic acid or chloride acid are the only wastes produced.

Design, Synthesis, and Evaluation of Donepezil-Like Compounds as AChE and BACE-1 Inhibitors

An ecofriendly synthetic pathway for the synthesis of donepezil precursors is described. Alternative energy sources were used for the total synthesis in order to improve yields, regioselectively, and rate of each synthetic step and to reduce the coproduction of waste at the same time. For all products, characterized by an improved structural rigidity respect to donepezil, the inhibitor activity on AChE, the selectivity vs BuChE, the side-activity on BACE-1, and the effect on SHSY-5Y neuroblastoma cells viability were tested. Two potential new lead compounds for a dual therapeutic strategy against Alzheimers disease were envisaged.

General MW-assisted grafting of MCM-41: Study of the dependence on time dielectric heating and solvent

A fast and versatile microwave- (MW)-assisted method for the post-calcination functionalization of MCM-41 is proposed. The efficiency of the grafting is improved in the absence of solvent and depends on the MW-heating time. Moreover, working under the same reaction conditions, the organic loadings strictly depend on the silylating agent.

An eco-sustainable erbium(III)-catalyzed method for formation/cleavage of O-tert-butoxy carbonates

A new simple and effective method for the formation/cleavage of O-tert-butoxy carbonates of alcohols and phenols is proposed. Mesoporous silica-supported Er(III) (ErIII-MCM-41) was used as an efficient and reusable solid catalyst in the solvent-free ultrasound-assisted synthesis of Boc-carbonate derivatives of a wide range of alcohols and phenols. The fast, selective deprotection of Boc-derivatives is achieved with a very low amount of Er(OTf)3 in ethanol under microwave irradiation. Therefore, the entire protection/de-protection process is very attractive, from the point of view of sustainability.