0000000001204001
AUTHOR
Maria Luisa Testa
showing 11 related works from this author
Dehydration of Fructose to 5-HMF over Acidic TiO2 Catalysts
2020
Different solid sulfonic titania-based catalysts were investigated for the hydrothermal dehydration of fructose to 5-hydroxymethylfurfural (5-HMF). The catalytic behavior of the materials was evaluated in terms of fructose conversion and selectivity to 5-HMF. The surface and structural properties of the catalysts were investigated by means of X-ray diffraction (XRD), N2 adsorption isotherms, thermo-gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and acid capacity measurements. Special attention was focused on the reaction conditions, both in terms of 5-HMF selectivity and the sustainability of the process, choosing water as the solvent. Among the various process condition…
A New Entry to the Substituted Pyrrolo[3,2-c]quinoline Derivatives of Biological Interest by Intramolecular Heteroannulation of Internal Imines.
2004
New 1,3,4-substituted pyrrolo[3,2-c]quinoline derivatives were synthesised in good yields by oxidative heteroannulation of internal imines starting from easily prepared substituted 5-(2-aminophenyl)pyrroles and commercially available aryl and heteroaryl aldehydes. The reaction occurs as a one-pot process involving an intramolecular acid catalysed reaction.
Reaction of 3-Methylamino-1,2-diols with Dihalomethanes. Synthesis of Chiral 4-Substituted 3-Methyltetrahydro-1,3-oxazin-5-ols
2000
Abstract Enantiomerically pure 4,5-disubstituted 3-methyltetrahydro-1,3-oxazines have been obtained by reaction of 3-methylamino-1,2-diols with dichloromethane by regioselective differentiation of hydroxyl groups.
Asymmetric synthesis of (−)-pseudoephedrine from (2S,3S)-3-phenyloxiran-2-ylmethanol. Stereospecific interchange of amino and alcohol functions
2001
Abstract A ring-opening reaction of N -methylaziridines with Boc 2 O/NaI has been applied to the asymmetric synthesis of pseudoephedrine. 3-Methylamino-3-phenyl-1,2-propanediol 1 , derived from (2 S ,3 S )-3-phenyloxiran-2-ylmethanol, was converted into the oxazolidin-2-one 4 , a precursor of pseudoephedrine. The reaction occurs with a stereospecific interchange of amino and alcohol functions.
Synthesis of new polydentate oxalamide-based ligands as chiral catalysts for the enantioselective addition of diethylzinc to benzaldehyde
2006
New polydentate oxalamide-based ligands have been studied as chiral catalysts in the enantioselective addition of diethylzinc to benzaldehyde
Oxidation of aminodiols mediated by homogeneous and heterogeneous TEMPO
2004
The conversion of amino diols to aminohy- droxy acids by oxidation of the primary hydroxy group mediated by homogeneous and heterogeneous TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl radi- cal) is reported. The synthesis uses NaOCl as primary oxidant and TEMPO, either dissolved in the homoge- neous phase or entrapped in a sol-gel matrix, as cata- lytic mediator. Homogeneous TEMPO is suitable for the oxidation of aliphatic methylamino diols, while the hybrid organic-inorganic silica sol-gel catalysts are more selective mediators for the oxidation of ben- zylic amino diols like the potent antibiotic chloram- phenicol which, under homogeneous conditions, are unselectively oxidized to benzoic ac…
Catalytic Dehydration of Fructose to 5-Hydroxymethylfurfural in Aqueous Medium over Nb2O5-Based Catalysts
2021
The catalytic dehydration of fructose to 5-hydroxymethylfurfural (HMF) in water was performed in the presence of pristine Nb2O5 and composites containing Nb and Ti, Ce or Zr oxides. In all experiments, fructose was converted to HMF using water as the solvent. The catalysts were characterized by powder X-ray diffraction, scanning electron microscopy, N2 physical adsorption, infrared and Raman spectroscopy and temperature-programmed desorption of NH3. Experimental parameters such as fructose initial concentration, volume of the reacting suspension, operation temperature, reaction time and amount of catalyst were tuned in order to optimize the catalytic reaction process. The highest selectivit…
Reactivity of β-amino alcohols against dialkyl oxalate: synthesis and mechanism study in the formation of substituted oxalamide and/or morpholine-2,3…
2012
The reactivity of various β-amino alcohols with dialkyl oxalates, in several reaction conditions, has been investigated. Linear disubstituted oxalamides were obtained with primary β-amino alcohols and linear tetrasubstituted oxalamides, or a mixture of linear tetrasubstituted oxalamides and cyclic morpholine-2,3-diones were obtained with N-substituted β-amino alcohols. A DFT study of the possible mechanism has been made. The theoretical results indicate that these reactions are not kinetically controlled, there is an equilibrium between all species and therefore follow a thermodynamic control. The different behavior between the primary β-amino alcohols and N-methyl β-amino alcohols is due t…
The young hard active Sun: soft X-ray irradiation of tryptophan in water solutions
2010
AbstractThe X-ray emission of the young Sun was much harder and intense than today and might have played a significant role in the evolution of complex organics in protoplanetary environments. We investigate the effects of soft X-rays on tryptophan molecules in aqueous solutions at room temperature. As results of the irradiation experiments we detect several light species indicative of fragmentation, together with large molecular structures such as tryptophan dipeptide and tripeptide. Complexification is more evident in H2O solution than in D2O, probably due to isotopic effects. The abundances of peptides depend on the irradiation dose and decrease with increasing energy deposition. Radical…
Novel examples of the N-methyl effect on cyclisations of N-Boc derivatives of amino alcohols. A theoretical study
2004
New examples of the N-methyl effect on the cyclisation of N-tert-butoxycarbonyl derivatives of amino alcohols are reported. Ab initio studies for the displacement step with formation of the five-membered heterocycle indicate that the increase of the nucleophile character of the carbonyl oxygen of the carbamate group with the N-methyl substitution is responsible for the acceleration of the cyclisation step.
Il Progetto ATENA: Applicazione di metodologie innovative per la conservazione di manufatti metallici e ceramici da scavo archeologico e per il recup…
2007
Qui di seguito viene illustrato il progetto scientifico ATENA, svolto presso l'Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) del Consiglio Nazionale delle Ricerche (CNR) e co-finanziato dal MIUR con Decreto Direttoriale 9-10-2002, n. 1105/2002. Il progetto si propone di applicare avanzate tecniche diagnostiche strumentali al fine di acquisire la dettagliata conoscenza microchimica e microstrutturale di manufatti metallici e ceramici antichi, di definirne il meccanismo di alterazione e/o degrado e di progettare, sintetizzare e validare opportuni prodotti e formulazioni per il restauro conservativo di tali manufatti. Le conoscenze acquisite sono utilizzabili anche per il recuper…