Active-alkali metal promoted reductive desulfurization of dibenzothiophene and its hindered analogues

Reductive desulfurisation of organic compounds is of importance both in organic synthesis and in industry. Benzo- and dibenzothiophenes are between the most abundant sulphur containing impurities in crude oils, and their desulfurization is a mandatory issue in the production of non polluting fuels. Following our interest in the development of efficient alkali metal-mediated synthetic procedures and alternative protocols for the chemical transformation of widespread environmental contaminants we wish to report here on the effectiveness of sodium and lithium metals, in the presence of catalytic amounts of tetraphenylethylene (TPE), in promoting the reductive desulfurization of dibenzothiophene, as well as of the corresponding sulfone and sulfoxide

Active-alkali metal promoted reductive desulfurization of dibenzothiophene and its hindered analogues

Reductive desulfurisation of organic compounds is of importance both in organic synthesis and in industry. Benzo- and dibenzothiophenes are between the most abundant sulphur containing impurities in crude oils, and their desulfurization is a mandatory issue in the production of non polluting fuels. Following our interest in the development of efficient alkali metal-mediated synthetic procedures and alternative protocols for the chemical transformation of widespread environmental contaminants we wish to report here on the effectiveness of sodium and lithium metals, in the presence of catalytic amounts of tetraphenylethylene (TPE), in promoting the reductive desulfurization of dibenzothiophene, as well as of the corresponding sulfone and sulfoxide

Electron-transfer-induced reductive dealkoxylation of alkyl aryl ethers. III. Reductive cleavage of methoxy-substituted <i>N</i>,<i>N</i>-dimethylanilines (<i>N</i>,<i>N</i>-dimethylanisidines)

The reactivity of the three isomeric methoxy-substituted N,N-dimethylanilines (N,N-dimethylanisidines) and of N,N-dimethyl-2,6-dimethoxyaniline in the reduction with alkali metals in aprotic solvents was investigated. N,N-Dimethyl-p-methoxyaniline was found to be unreactive, while the other substrates underwent exclusive cleavage of carbon-oxygen bond(s), with the following order of reactivity: 2,6-dimethoxy > o-methoxy > m-methoxy > p-methoxy. Both the relative reactivity and the regioselectivity of cleavage (demethoxylation vs. demethylation) was found to parallel closely that of the corresponding di- and trimethoxysubstituted substrates. These results suggest that intermediates with different electron distribution or even different intermediates are involved in the reductive cleavage of aryl-oxygen and arylnitrogen bonds

Produktivna reintegracija iseljenika povratnika i seoski turizam: život i radna iskustva u Sardiniji (Italija) i u gorskom predjelu provincije Marakeš (Maroko)

The paper provides a contribution to the formulation of return migration policies that seek to harness the skills gained by emigrants and channel their savings into the creation of small businesses within a local development scheme. We have drawn from experiences described by return emigrants, gathered in Sardinia and in the Marrakech province in Morocco, to formulate measures capable of generating positive opportunities for encouraging the return of migrants to their home areas, utilizing the skills gained in the hospitality industry in Europe and investing their savings in their country. The measures are also designed to offer return migrants an alternative to settling in urban destinations. The case study is concerned with a rural tourism initiative in subcoastal and interior areas as an alternative to marine and coastal tourism. Based on the premise that only those areas with a natural and cultural heritage offer good potential for the development of rural tourism, the following conclusions are presented: a) one seemingly useful form of action is for the authorities in the host countries to organise training courses for migrant workers, within the cooperation framework for assisting migrants to return to their home countries; b) it is essential for local authorities in the migrants’ home countries to improve transportation systems, facilities and tourist services in general; c) equally important in the home countries is the adoption of measures aimed at the recognition, rehabilitation and enhancement of the archaeological heritage, material culture and of traditions in general, together with the natural/ environmental resources for an integrated tourist product.Rad predstavlja doprinos u oblikovanju migracijskih politika povratka koje nastoje iskoristiti stečene vještine iseljenika te usmjeriti njihove uštede u otvaranje malih poslova (businessa) unutar programa lokalnog razvoja. U formuliranju mjera koje mogu stvoriti pozitivne mogućnosti za povratak migranata u njihova rodna mjesta koristeći njihove vještine stečene u industriji zemalja primitka i ulažući uštede u svoju zemlju, autori su se oslonili na iskustva iseljenika povratnika prikupljenih na Sardiniji i u provinciji Marakeš u Maroku. Te mjere iseljenicima povratnicima također trebaju ponuditi i mogućnost naseljavanja u urbanim sredinama. Studija slučaja bavi se inicijativom za pokretanje seoskog turizma u priobalnim i unutrašnjim predjelima kao alternativom za nautički i obalni turizam. Pod pretpostavkom da samo krajevi s prirodnom i kulturnom baštinom pružaju dobre mogućnosti za razvoj seoskog turizma, ponuđeni su sljedeći zaključci: a) čini se da bi bilo korisno kada bi vlasti u zemljama primitka organizirale tečajeve osposobljavanja za radnike migrante unutar okvira suradnje za pomoć migrantima za povratak u domovinu; b) bitno je da lokalne vlasti u zemlji podrijetla migranata općenito poboljšaju sustav prijevoza, te popratne pogodnosti i turističke usluge; c) u zemljama podrijetla jednako je tako važno usvojiti mjere kojima je cilj prepoznavanje, obnova i povećanje arheološke baštine, materijalne kulture i tradicije općenito, zajedno s prirodnim/ekološkim resursima kako bi se stvorio integrirani turistički proizvod

Green and convenient arene-catalized reductive lithiation of heterocyclic compounds

In the last decades reductive lithiation established itself as a particularly powerful procedure for the generation of functionalized organometals. In addition, the enormous role of this reaction in the reductive ring opening and functionalization of heterocycles has been reported. Accordingly, critical experiments were performed for the generation of lithium radical anions of several PAHs and a diene in both solvents, under both CA and SA protocols. Almost all of the above mentioned hydrocarbons rapidly generate radical anions with different fascinating visible colors at 0 °C. Based on this, influence of different electron shuttles and their efficiency in the reductive lithiation of N-phenylaziridine, phthalan will be disclosed. Moreover, we will report an interesting example of chemoselectivity concerning to the reductive lithiation of 4-chlorobenzyl methyl ether in a green solvent

Lithiation of 4-membered heterocycles as useful strategy for the preparation of new molecular scaffolds: addressing the regioselectivity in azetidines and thietanes

Four-membered heterocycles (4-MH) with one or two heteroatoms are of great importance in medicinal chemistry and synthetic organic chemistry. This kind of scaffolds show peculiar structural features, related to the ring “puckering”, and biological properties. Our recent research efforts have been focused on the stereoselective synthesis and functionalization of some 4-MH such as azetidines, thietanes and oxazetidines

Nuove prospettive nella sintesi degli acidi peptido nucleici

Gli acidi peptido nucleici, comunemente chiamati PNA (Peptide Nucleic Acids), sono mimetici del DNA, in cui la sequenza delle nucleobasi (le stesse del DNA), è inserita in uno scheletro poliammidico achirale. Data la notevole importanza dei PNA, il nostro gruppo di ricerca ha studiato la messa a punto di un processo di sintesi dei singoli monomeri PNA, efficiente e riproducibile, privo, per quanto possibile, di purificazioni cromatografiche degli intermedi, che consenta di ottenere i monomeri su larga scala. Si è inoltre cercato di ottenere monomeri in cui fosse rispettata l’ortogonalità tra i vari gruppi protettori (Pg1, Pg2, Pg3) dello scheletro e delle nucleobasi

Riduzione regioselettiva del 3,4,5-trimetossibenzil metil etere: sintesi di resorcinoli 2,5-dialchilsostituiti

Vista l'esperienza maturata nel nostro laboratorio nella generazione di reattivi organometallici di tipo benzilico e aromatico attraverso reazioni di metallazione riduttiva di alchil benzil eteri, abbiamo ritenuto che il metil etere dell'alcool 3,4,5-trimetossibenzilico, fosse un substrato adatto alle nostre necessità sintetiche

Metallazione riduttiva di 1,2-diarileteni: applicazioni sintetiche

Proseguendo nella nostra ricerca di nuove ed efficienti procedure basate sull’utilizzo di metalli alcalini in sintesi organica, abbiamo studiato la reazione di metallazione riduttiva di una serie di 1,2-diariletileni, e le possibili applicazioni sintetiche dei derivati vicdiorganometallici così ottenuti

Venezuelan Equine Encephalitis Viruses (VEEV) in Argentina: Serological Evidence of Human Infection

Venezuelan equine encephalitis viruses (VEEV) are responsible for human diseases in the Americas, producing severe or mild illness with symptoms indistinguishable from dengue and other arboviral diseases. For this reason, many cases remain without certain diagnosis. Seroprevalence studies for VEEV subtypes IAB, ID, IF (Mosso das Pedras virus; MDPV), IV (Pixuna virus; PIXV) and VI (Rio Negro virus; RNV) were conducted in persons from Northern provinces of Argentina: Salta, Chaco and Corrientes, using plaque reduction neutralization test (PRNT). RNV was detected in all studied provinces. Chaco presented the highest prevalence of this virus (14.1%). Antibodies against VEEV IAB and -for the first time- against MDPV and PIXV were also detected in Chaco province. In Corrientes, seroprevalence against RNV was 1.3% in the pediatric population, indicating recent infections. In Salta, this was the first investigation of VEEV members, and antibodies against RNV and PIXV were detected. These results provide evidence of circulation of many VEE viruses in Northern Argentina, showing that surveillance of these infectious agents should be intensifiedFil: Pisano, María Belén. Universidad Nacional de Córdoba. Facultad de Medicina. Instituto de Virología; ArgentinaFil: Oria, Griselda. Universidad Nacional del Nordeste. Instituto de Medicina Regional; ArgentinaFil: Beskow, Geraldine. Universidad Nacional del Nordeste. Instituto de Medicina Regional; ArgentinaFil: Aguilar, Juan Javier. Universidad Nacional de Córdoba. Facultad de Medicina. Instituto de Virología; ArgentinaFil: Konigheim, Brenda Salome. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); ArgentinaFil: Cacace, Maria Luisa. Hospital San Vicente de Paul, Orán; ArgentinaFil: Aguirre, Luis. Hospital Dante Tardelli; ArgentinaFil: Stein, Marina. Universidad Nacional del Nordeste. Instituto de Medicina Regional; ArgentinaFil: Contigiani de Minio, Marta Silvia. Universidad Nacional de Córdoba. Facultad de Medicina. Instituto de Virología; Argentin