1,678 research outputs found
Synthesis of tetrathia[7]helicenes promoted by Pd-catalysed cross coupling reactions
No full textTetrathia[7]helicenes (7-TH), formed by thiophene and benzene rings ortho-fused in an alternating fashion, are emerging as one of the most popular class of chiral helical-shaped molecules [1], thanks to their unique electronic and optical properties suitable for applications in optoelectronics [2], biomolecular recognition [3], and asymmetric catalysis [4]. Despite all these potential advantages, most of the synthetic methodologies to prepare 7-TH systems involve oxidative photochemical cyclization processes, which require specific equipment, highly diluted solutions, and can limit the scale-up of the synthesis of these derivatives. In our ongoing studies on the preparation of 7-TH derivatives, we have set up an innovative and non-photochemical synthesis of 7,8-diaryl substituted 7-TH compounds, exploiting Suzuki-type reactions and Pd-catalysed annulation with diaryl alkynes. [1] Dova, D.; Cauteruccio, S.; Prager, S.; Dreuw, A.; Graiff, C.; Licandro E. J. Org. Chem. ASAP (DOI: 10.1021/acs.joc.5b00243)
[2] Bossi, A.; Licandro, E.; Maiorana, S.; Rigamonti, C.; Righetto, S.; Stephenson, G. R.; Spassova, M.; Botek, E.; Champagne, B. J. Phys. Chem. C 2008, 112, 7900.
[3] Cauteruccio, S.; Bartoli, C.; Carrara, C.; Dova, D.; Errico, C.; Ciampi, G.; Dinucci, D.; Licandro, E.; Chiellini, F. Chem. Plus. Chem. 2015, 80, 490.
[4] Cauteruccio, S.; Dova, D.; Benaglia, M.; Genoni, A.; Orlandi, M.; Licandro, E. Eur. J. Org. Chem. 2014, 2694
Functionalization of phospha-thiahelicenes and application of their gold(I) complexes in enantioselective catalysis
No full textHelically chiral structures are known to display peculiar properties and applications in many fields, including asymmetric catalysis. However, both the synthesis of helical phosphorus ligands and their uses in enantioselective organometallic catalysis have been underdeveloped so far [1].
In the course of our studies on helical phosphane derivatives as potential chiral ligands in asymmetric organometallic catalysis [2], we have recently reported the synthesis of a new chiral phospha-thiahelicene based gold (I) complex, which is an excellent and selective pre-catalyst for the enantioselective cycloisomerization of N-tethered enynes [3].
On the basis of these very promising results we have effectively functionalized the phospha-thiahelicene scaffold to obtain new gold (I) complexes, which are then tested as pre-catalysts in other challenging enantioselective cycloisomerization reactions. 1. a) Y. Shen, C.-F. Chen, Chem. Rev. 2012, 112, 1463; b) P. Aillard , A. Voituriez, A. Marinetti, Dalton
Trans. 2014, 43, 15263.
2. a) S. Cauteruccio, A. Loos, A. Bossi, M. C. Blanco Jaimes, D. Dova, F. Rominger, S. Prager, A. Dreuw, E.
Licandro, A. S. K. Hashmi, Inorg. Chem. 2013, 52, 7995; b) K. Yavari, P. Aillard, Y. Zhang, F. Nuter, P.
Retailleau, A. Voituriez, A. Marinetti, Angew. Chem. Int. Ed. 2014, 53, 861.
3. P. Aillard, A. Voituriez, D. Dova, S. Cauteruccio, E. Licandro, and A. Marinetti, Chem. Eur. J. 2014, 20,
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THE EVOLUTION OF FINAL FINANCIAL RESULTS IN TIME
No full textThe auditor�s knowing and understanding of the respective economic segment, the detailed analysis of the relations between income and results on account of time, motivate us to use the method of extrapolation and include it in the auditing procedures.dispersion cloud, extrapolation, harmonization point
«NIENTE NEL MONDO È UN OGGETTO IN SÈ». IL “SEN-SO” DELLA NORMA PENALE TRA LEGALITÀ, OFFENSIVITÀ E SUSSIDIARIETÀ
No full textThe essay, focused on the idea of “substantive criminal law”, explores the ways criminal legal system can adequately conveyan interpretation of norms really compliant with legality principle , being well known how the hermeneutic process is deeply affected by a pre-comprehension of facts to which norms are applied thus exposing judicial decisions to the risk of arbitrariness. In order to guide in the selection of relevant facts or features thereof, and then to rejuvenate a really weakened ability of criminal law ro substtaìtially steer legal decisions, the ultima ratio principle should be considered not just in the law-making, but also in judicial decisions, just for a better understanding of other basic principles like the harm and legality ones. This can be achieved through the awareness of the “positional” logic (in a meaning the author draws from Ludwig Wittgestnein’s philosophy) just inherent in the idea of criminal law as ultima ratio, namely to be deployed for social control only after having considered the ability of other means to protect relevant interests
Il giudice di fronte alla prova scientifica
No full textIl contributo analizza il ruolo del giudice di fronte alla prova scientifica
Confronto tra porto-TC e Lipiodol-TC nella stadiazione del carcinoma epatocellulare.
No full textEighteen patients (13 men and 5 women) with uni- and multifocal hepatocellular carcinomas (HCC) were examined. Mean patients age was 63.3 years (range: 47-74 years). All patients had alcoholic or posthepatitis cirrhosis; they were submitted to both CT during arterial portography (APCT) and Lipiodol-CT. The diagnosis of HCC was confirmed by fine-needle biopsy (FNB) in all cases. APCT and Lipiodol-CT results were compared for number, size and site of lesions-32 lesions in all. APCT demonstrated all the lesions: 9 of them were smaller than 2 cm, 14 ranged 2-5 cm and 9 were bigger than 5 cm; moreover, APCT demonstrated other lesions in 3/18 patients (16.6%) which had been missed by US, CT and angiography. Also Lipiodol-CT demonstrated all the 32 lesions and showed smaller lesions in 4/18 patients (22.2%); these nodules were smaller than 2 cm. Based on APCT results 11/18 patients (61.1%) were considered operable, vs. 7/18 patients (38.8%) based on Lipiodol-CT results. To conclude, both APCT and Lipiodol-CT are useful in the preoperative staging of HCC; Lipiodol-CT is preferable to APCT in the study of lesions smaller than 2 cm
La messa alla prova per adulti nel territorio di Milano. Analisi dell’applicazione di una misura innovativa nel panorama sanzionatorio italiano = Adult probation in the Court District of Milan. Analysis of an innovative measure in the Italian sanctions system
No full textLa legge delega n. 67 del 2014 ha introdotto nell’ordinamento italiano l’istituto della messa alla prova per adulti. Dopo una breve descrizione del contesto in cui si colloca l’introduzione della misura e dopo averne messo in luce le caratteristiche in-novative, si analizzano e discutono i risultati di una ricerca valutativa (SWOT analysis) partecipata dagli attori coinvolti a vario titolo nella gestione dei casi di messa alla prova per adulti nell’ambito territoriale del Tribunale di Milano. Basata su 23 interviste, la ricerca illustra i punti di forza e di debolezza, le minacce e le opportunità legate all’applicazione della misura. Alla luce di quanto emerso, l’articolo si conclude con la presentazione di un vademecum di interventi prioritari per migliorare l’efficacia dell’istituto.Within the law n. 67/2014, the Italian legislation introduced a new kind of pre-trial probation. After a description of the innovative aspects of the law and an analysis of the context in which it wasapproved, an evaluation study (SWOT analysis) conducted in the city of Milan is presented. Based on 23 interviews to stakeholders, the research shows Strengths, Weaknesses, Opportunities and Threats in the application of the new measure. In the light of research findings, the paper proposes a vademecum with priority actions to improve the efficacy of the law
Thiahelicenes: from basic knowledge to applications
No full textThiahelicenes are helical-shaped polyaromatic conjugated molecules which, in the majority of cases, alternate benzene and thiophene rings. Examples in which only thiophene rings are present are also known. Both types of thiahelicenes are intrinsically chiral molecules and the configurationally stable M and P enantiomers can be separated using different techniques. Thiahelicenes ending with thiophene rings can be easily and regioselectively functionalized by direct electrophilic substitution or through generation of α-anions on the terminal thiophene rings, followed by reaction with electrophiles.Substitution on inner benzene rings can best be achieved by starting from properly functionalized precursors. Hence, steric and electronic properties of thiahelicenes can be modulated by introducing substituents of different nature and size on the helical scaffold. The theoretical investigation of these systems allows prediction of thiahelicenes' physical and optical properties.Applications of thiahelicenes span many different field such as material science, optoelectronics, catalysis, polymers, biology, and others.Despite the already acquired knowledge on thiahelicenes, several aspects must still be addressed, such as the establishment of efficient synthetic methodologies for obtaining pure enantiomers for the abovementioned applications.The authors believe that the investigation of thiahelicenes potential in biology deserves greater attention, because this topic is still in its infancy stage. Preliminary studies show interaction of thiahelicenes with DNA and can be the starting point for wider investigations of unusual biological applications.We hope this chapter will stimulate the interest of researchers not only in the field of chemistry but also in biology and physics
Thiahelicene phosphorous derivatives
No full textTetrathia[7]helicenes (7-TH) are polyconjugated π-systems in which four thiophene rings are ortho-fused to alternating arene rings to generate a non planar and chiral helix, which allows the existence and the separation of the M and P antipodes. Exploiting our well-established know-how in the synthesis and functionalization of 7-TH derivatives, we have recently focused our attention on the study of new 7-TH phosphorous derivatives as potential chiral ligands in asymmetric organometallic catalysis1 and organocatalysis.2
Based on the promising results obtained in these studies, new classes of 7-TH phosphorous derivatives, whose structures are reported in Figure 1, have been synthesized, and their chiroptical, structural, electronic and electrochemical properties have been investigated
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