Giovanni Sotgiu

Oxirane rings: studies and applications of a new chemo and regio selective reductive opening of epoxides

Abstract the straightforward reductive opening of 1,2 epoxides to alcohols was studied and applied to several significant compounds. The reaction, which proceeds via the nucleophilic opening of the oxirane ring and the subsequent free radical dehalogenation, shows an excellent chemical yield as well as chemo and regioselectivity. This reaction was also applied to a chiral α,β-epoxyester.

Influence of surface roughening of Titanium substrate in the electrochemical activity of Manganese oxide thin film electrode in anodic oxidation of dye-containing solutions

Previous work has verified the possibility to obtain mechanically, chemically and electrically stable electrodes based on manganese oxide (MnOx) thin films for anodic oxidation of solutions containing the Reactive Violet 5 (RV5) azo dye. To improve the morphological and electrochemical properties of these materials, in this study, a surface modification of the titanium support has been presented. Chemically modified surfaces were obtained by etching titanium substrates in hydrocloridric acid at high temperature. Untreated and modified electrodes were coated sequentially with a RuOx film, as interlayer and a MnOx film obtained by adopting three different techniques including anodic electrodeposition, cathodic electrodeposition and thermal decomposition. Surface morphology, topography and composition of all the electrodes were investigated by profilometric and TOF–SIMS analysis. The electrochemical activity of anodes were first determined by cyclic voltammetry, and then in the treatment of solutions containing the RV5 azo dye, as model pollutant, in undivided cell under galvanostatic conditions. The results show that the surface microstructure modifies substantially the electrochemical response of selected electrodes.

Production and characterization of manganese oxide-based electrodes for anodic oxidation of organic compounds

Production and Characterization of Manganese OxideBased Electrodes for Anodic Oxidation of Organic Compounds Giovanni Sotgiu, Matteo Foderà, Francesco Marra, Elisabetta Petrucci a Dipartimento di Ingegneria, Università di Roma Tre, Via Vito Volterra, 62 00146, Roma b Dipartimento di Ingegneria Chimica Materiali Ambiente, Università degli Studi di Roma “La Sapienza”,Via Eudossiana, 18 00184, Roma *elisabetta.petrucci@uniroma1.it

A SAFE SYNTHESIS OF SYMMETRICAL CARBONATES FROM ALKYL HALIDES AND TETRAETHYLAMMONIUM CARBONATE

ABSTRACT A safe and mild procedure for the synthesis of organic carbonates from alkyl halides and tetraethylammonium carbonate (TEAC) is described. This method avoids the use of classical toxic and harmful chemicals like phosgene and carbon monoxide and works under very mild reaction conditions. An electrochemically-generated derivative of carbon dioxide (a cheap and abundant carbon source) was used as the main reagent (TEAC).

An efficient electrochemical method for N-acryloylation of oxazolidin-2-one chiral auxiliaries with α, α'-di- and trichloroketones

Abstract A new synthesis of N-enoyloxazolidin-2-ones has been performed by electrochemical reduction of α,α′-di- and trichloroketones in aprotic solvent in the presence of Evans’ chiral auxiliaries (oxazolidin-2-ones). The electrochemical reduction of trichloroketones via a chlorocyclopropanone as intermediate allows a Favorskii rearrangement involving trichloroketones and oxazolidin-2-ones. N-Enoyloxazolidin-2-ones have been obtained this way under mild reaction conditions and in good to high yields.

Electrochemically Induced N-Acryloylation of Chiral Oxazolidin-2-ones

A new method for N-acryloylation of Evans’ chiral auxiliaries (oxazolidin-2-ones) with α,α′-dichloro ketones in the presence of the electrogenerated base 2-pyrrolidone anion is described. N-Enoyloxazolidin-2-ones are obtained, under mild reaction conditions, in good to high yields.

Manganese-containing mixed oxide electrodes as anode materials for degradation of model organic pollutants

Mixed oxide thin film electrodes have been prepared by thermal decomposition from alcoholic solution on Pt substrate. In particular, three different anodes have been obtained by co-deposition of Ru (Ruthenium) and Mn (Manganese) oxides, Ru, Mn and Cu (Copper) oxides and co-deposition of Ru, Mn and Co (Cobalt) oxides. The electrochemical behaviour of the prepared electrodes was evaluated by potentiodynamic polarization curves and cyclic voltammetry tests. We also tested and compared their oxidizing ability in the degradation of aqueous solutions containing methyl orange as model compound and small amount of chloride. Galvanostatic experiments were conducted in a membrane-free reactor. The treatment extent was assessed by detection of color and TOC decay. The electrogeneration of active chlorine, chlorate and perchlorate was also monitored. The preliminary results show that ternary oxides coated electrodes exhibit enhanced electrocatalytic activity without producing undesired chlorinated by-products.

Reactivity of Electrogenerated Imidazole-2-Ylidenes in Ionic Liquids: Synthetic Implications

The cathodic reduction of an imidazolium ionic liquid, under galvanostatic conditions, leads to the formation of the corresponding carbene, imidazole-2-ylidene, and molecular hydrogen. This carbene can behave as a base and/or as a nucleophile, depending on the reaction partner. In particular, we have studied the reactivity of this N-heterocyclic carbene in alkylation and acylation reactions, in the synthesis of β-lactams, in the Henry reaction, in the synthesis of thiones and in the benzoin condensation