New and More Sustainable Processes for the Synthesis of Phenolics: 2-phenoxyethanol and hydroxytyrosol

The research work has dealt with the study of new catalytic processes for the synthesis of fine chemicals belonging to the class of phenolics, namely 2-phenoxyethanol and hydroxytyrosol. The two synthetic procedures investigated have the advantages of being much closer to the Green Chemistry principles than those currently used industrially. In both cases, the challenge was that of finding catalysts and methods which led to the production of less waste, and used less hazardous chemicals, safer solvents, and reusable heterogeneous catalysts. In the case of 2-phenoxyethanol, the process investigated involves the use of ethylene carbonate (EC) as the reactant for phenol O-hydroxyethylation, in place of ethylene oxide. Besides being a safer reactant, the major advantage of using EC in the new synthesis is the better selectivity to the desired product achieved. Moreover, the solid catalyst based on Na-mordenite was fully recyclable. The reaction mechanism and the effect of the Si/Al ratio in the mordenite were investigated. In the case of hydroxytyrosol, which is one of the most powerful natural antioxidants, a new synthetic procedure was investigated; in fact, the method currently employed, the hydrolysis of oleuropein, an ester extracted from the waste water processing of the olive, makes use of large amounts of organic solvents (hexane, ethyl acetate), and involves several expensive steps of purification. The synthesis procedure set up involves first the reaction between catechol and 2,2-dimethoxyacetaldehyde, followed by the one-pot reduction of the intermediate to give the desired product. Both steps were optimized, in terms of catalyst used, and of reaction conditions, that allowed to reach ca 70% yield in each step. The reaction mechanism was investigated and elucidated. During a 3-month period spent at the University of Valencia (with Prof. A. Corma’s group), a process for the production of diesel additives (2,5-bis(propoxymethyl)furan) from fructose has been investigated

Nuovi processi "green" per la funzionalizzazione di composti fenolici.

L’obiettivo di questo lavoro è lo studio della funzionalizzazione del fenolo mediante vie sintetiche “green”, che utilizzino quindi reagenti non clorurati e catalizzatori eterogenei, quindi facilmente recuperabili e riutilizzabili. Esistono però altri derivati fenolici di interesse commerciale, quali il catecolo, in quanto reagente di partenza per svariate molecole (tra cui appunto il DOPET) utilizzate in vari ambiti applicativi (alimentare, cosmetica, farmaceutica, agrochimica). In particolare, lo studio è stato focalizzato sulla sintesi dell’IDROSSITIROSOLO (o DOPET). Le prove effettutate con fenolo non hanno portato alla formazione del composto desiderato, ma di altri prodotti che comunque hanno interesse commerciale; ad esempio, è stato ottenuto il 2-fenossietanolo con elevata resa e selettività. Oltre al fenolo, ho studiato la reattività del metilendiossobenzene; con entrambi è stato ottenuto (seppur con basse rese) l’attacco all’anello da parte dell’etil gliossilato, formando così un intermedio potenzialmente utile per la sintesi dell’idrossitirosolo

Carbonates as reactants for the production of fine chemicals: a greener way to ethoxyphenol synthesis

none5noneP. Ziosi; F. Cavani; S. Cocchi; P. Righi; T. TabanelliP. Ziosi; F. Cavani; S. Cocchi; P. Righi; T. Tabanell

A two-step process for the synthesis of hydroxytyrosol

A new process for the synthesis of hydroxytyrosol (3,4-dihy-droxyphenylethanol), the most powerful natural antioxidant currently known, by means of a two-step approach is reported. Catechol is first reacted with 2,2-dimethoxyacetaldehyde in basic aqueous medium to produce the corresponding mandelic derivative with > 90 % conversion of the limiting reactant and about 70 % selectivity to the desired para-hydroxyalkylat-ed compound. Thereafter, the intermediate is hydrogenated to hydroxytyrosol by using a Pd/C catalyst, with total conversion of the mandelic derivative and 68 % selectivity. This two-step process is the first example of a synthetic pathway for hydroxytyrosol that does not involve the use of halogenated components or reduction methodologies that produce stoichiometric waste. It also avoids the complex procedure currently used for hydroxytyrosol purification when it is extracted from wastewa-ter of olive oil production

La Terra delle meraviglie. Teatro e musica tra Ville e Delizie

Il lettore-spettatore percorrerà un viaggio affascinante dove potrà scorgere – tra Ville e Delizie – la bellezza frugale o febbrile, l’estro e i dirompenti sensi che legano lo spartito alla partitura delle nostre esistenze. Queste pagine vogliono essere una riflessione sulla ricerca del sapere e uno studio sulla genesi dell’arte nelle sue espressioni teatrali e musicali, in una terra, quella italiana, modellata dalla civiltà dell’uomo. Da un teatro palladiano al concerto delle dame, da un pirotecnico spettacolo rinascimentale alla melodia polifonica, dalla tragedia greca alla compagnia dei Bardi, dal 'recitar cantando' al Paese del melodramma, il suono e il ritmo si fonderanno con l’inchiostro per plasmare l’essenza della musica e scandirne le diverse virtù ('ethos') tra uomo e natura, 'mousiké' e 'oikos'. Suoni, visioni e conoscenza come momenti per avvicinarsi delicatamente al mistero della voce umana che prende sembianze diverse: ora lamento amoroso e inno, ora rappresentazione teatrale e finzione, ora maschera e segreto. 45 contributi, 42 autori (docenti universitari, studiosi, musicologi). Tavole fuori testo a colori. Prefazione di Marco Dorigatti, University of Oxford