Supporting Cubane’s Renaissance: Metathesis reactions on 4-iodo-1-vinylcubane and Stetter reaction on 1-iodocubane-4-carboxaldehyde

Cubane is a peculiar cube-shaped alkane molecule with a rigid, regular structure. This makes it a good scaffold, i.e. a molecular platform to which the substituents are arranged in a specific and fixed orientation. Moreover, cubane has a body diagonal of 2.72 Å, very similar to the distance across the benzene ring, i.e. 2.79 Å. Thus, it would be possible to use cubane as a scaffold in medicinal and material chemistry as a benzene isostere 1,2. This could lead to advantages in terms of solubility and toxicity and could provide novel properties. For this purpose, the possibility of performing “modern organic chemistry” on the cubane scaffold has to be studied. This project was entirely carried out in the framework of the Erasmus+ mobility programme at the Trinity College (Dublin, IRL) under the supervision of prof. M. O. Senge. The main goal of this project was to widen the knowledge on cubane chemistry. In particular, it was decided to test reactions that were never applied to the scaffold before, such as metathesis of 4-iodo-1-vinylcubane and Stetter reaction of 1-iodocubane-4-carboxaldehyde. These two molecules were synthesized in 10 and 9 steps respectively from commercially available cyclopentanone, following a known procedure. Unfortunately, metathesis with different olefins, such as styrene, α,β unsaturated compounds and linear α-olefins failed under different conditions, highlighting cubane behaves as a Type IV, challenging olefin under metathesis conditions. Even the employment of a specific catalyst for hindered olefins failed in the cross-coupling with linear α-olefins. On the other hand, two new molecules were synthesized via Stetter reaction and benzoin condensation respectively. Even if the majority of the reactions were not successful, this work can be seen as an inspiration for further investigation on cubane chemistry, as new questions were raised and new opportunities were envisioned

L’ascrizione tribale dei minori nelle "regiones" X e XI*

The analysis of tribal ascription in such a circumscribed area as Regiones X and XI can nevertheless provide us some substantial hints that permit to consider in a wider and more general sense an issue which has been little dealt with until today: the juvenile tribal ascription. Considered essentially as an irregular feature, it seems to meet some Roman society’s specific needs, in particular the need to celebrate the defunct’s future role as a citizen, or the need to reaffirm the importance of a certain gens in the context of its community, or even the necessity to point out the social advancement achieved by lower classes.L’ascrizione tribale dei minori nelle Regiones X e XIL’analisi della ascrizione tribale di una area geografica tanto delimitata come le Regiones X e XI può comunque fornirci validi suggerimenti per considerare, in un modo più ampio e generale, una questione fino ad oggi poco affrontata: l’ascrizione tribale minorile. Ritenuta sostanzialmente irregolare, l’ascrizione tribale minorile parrebbe rispondere ad alcune esigenze specifiche della società romana, in particolare la necessità di celebrare, nel defunto, il suo ruolo di futuro cittadino o di ribadire l’importanza di una determinata gens nel contesto di una comunità o di sottolineare l’avvenuto avanzamento sociale degli strati più bassi

Advances in Catalytic Routes for the Homogeneous Green Conversion of the Bio-Based Platform 5-Hydroxymethylfurfural

5-Hydroxymethylfufural (HMF) is an intriguing platform molecule that can be obtained from biomasses and that can lead to the production of a wide range of products, intermediates, or monomers. The presence of different moieties in HMF (hydroxy, aldehyde, furan ring) allows to carry out different transformations such as selective oxidations and hydrogenations, reductive aminations, etherifications, decarbonylations, and acetalizations. This is a great chance in a biorefinery perspective but requires the development of active and highly selective catalysts. In this view, homogeneous catalysis can lead to efficient conversion of HMF at mild reaction conditions. This Review discussed the recent achievements in homogeneous catalysts development and application to HMF transformations. The effects of metal nature, ligands, solvents, and reaction conditions were reported and critically reviewed. Current issues and future chances have been presented to drive future studies toward more efficient and scalable processes

Chapter Il volto settecentesco del territorio bresciano: il barocco classicista della famiglia Marchetti

The 43rd UID conference, held in Genova, takes up the theme of ‘Dialogues’ as practice and debate on many fundamental topics in our social life, especially in these complex and not yet resolved times. The city of Genova offers the opportunity to ponder on the value of comparison and on the possibilities for the community, naturally focused on the aspects that concern us, as professors, researchers, disseminators of knowledge, or on all the possibile meanings of the discipline of representation and its dialogue with ‘others’, which we have broadly catalogued in three macro areas: History, Semiotics, Science / Technology. Therefore, “dialogue” as a profitable exchange based on a common language, without which it is impossible to comprehend and understand one another; and the graphic sign that connotes the conference is the precise transcription of this concept: the title ‘translated’ into signs, derived from the visual alphabet designed for the visual identity of the UID since 2017. There are many topics which refer to three macro sessions: - Witnessing (signs and history) - Communicating (signs and semiotics) - Experimenting (signs and sciences) Thanks to the different points of view, an exceptional resource of our disciplinary area, we want to try to outline the prevailing theoretical-operational synergies, the collaborative lines of an instrumental nature, the recent updates of the repertoires of images that attest and nourish the relations among representation, history, semiotics, sciences

The lines of madness. The inscription CIL VI, 21757 in a drawing at the Christ Church College attributed to Bernardino da Parenzo

La rianalisi di un disegno attribuito un tempo ad Andrea Mantegna consente di esaminare la curiosa vicenda di trasmissione dell’iscrizione CIL VI, 21757, oggi perduta, e di studiare un interessante caso di reimpiego di un testo epigrafico all’interno di un programma iconografico complesso e discusso che ha generato a sua volta varianti e rielaborazioni.The reanalysis of a drawing that was once attributed to Andrea Mantegna permits to examine the curious account regarding the transmission of the epigraph CIL VI, 21757, which is lost at present. It also permits to study an interesting case of reuse of an epigraphic text within a complex and debated iconographic program, that has in turn generated variations and re-elaborated versions

La cartografia dell’uso e copertura del suolo: uno strumento per rilevare il cambiamento del territorio lombardo

At the beginning of the 2000’s Regione Lombardia and ERSAF began a cartographic survey program addressing small-scale land cover and usage. First it was necessary to have detailed geographic databases of the entire region available and then to monitor the developmental changes of the region. The information layers that were products consisted of polygonal features (usage and land cover) and linear features (hedges and rows). The thematic map construction was prevalently carried out by photo-interpretation of aerial images. The adopted classification was divided into five hierarchical levels where the first three consisted of classes of CORINE Land Cover. The need to represent some local peculiarities has led to the introduction of two additional levels (IV and V), which describe the characteristic features of the Lombardy region. During the past years the program has become well established and has led to the creation of the layers relative to five di erent historical moments: 1954/1955, 1980 (data of less detail), 1999, 2007, and 2012

Layered-double hydroxides and derived oxide as CRM-free highly active catalysts for the reduction of 4-nitrophenol

The present study investigates the possibility to abate 4-nitrophenol (4NP), a well-known persistent contaminant in wastewaters, using Layered-Double Hydroxides (LDH) based catalysts, non-noble metals-based and Critical Raw Materials-free materials used for 4NP reduction with NaBH4. It is reported the study of the effects of several parameters on the overall reaction kinetic by in situ monitoring of the 4NP reduction through UV-Vis Spec-troscopy, as: (i) LDH's trivalent and divalent cation nature, (ii) LDH thermal treatment, (iii) substrate/catalyst ratio, and (iv) stirring rate. The reasons that led to increased activity were identified and correlated with cat-alyst's structure characterization. The results pointed out that LDH enhance synergic effect of nickel and copper by increasing reducibility which is further raised when defective mixed oxide by calcination is obtained. This resulted in enhanced 4NP reduction which could be further increased by calcination providing a highly reducible mixed oxide

H2 Production by Methane Oxy-Reforming: Effect of Catalyst Pretreatment on the Properties and Activity of Rh-Ce0.5Zr0.5O2 Synthetized by Microemulsion

Green hydrogen introduction in hard-to-abate processes is held back by the cost of substituting steam reforming plants with electrolyzers. However, green hydrogen can be integrated in properly modified reforming processes. The process proposed here involves the substitution of steam reforming with oxy-reforming, which is the coupling of the former with catalytic partial oxidation (CPO), exploiting the pure oxygen coproduced during electrolysis to feed CPO, which allows for better heat exchange thanks to its exothermic nature. With the aim of developing tailored catalysts for the oxy-reforming process, Ce0.5Zr0.5O2 was synthetized by microemulsion and impregnated with Rh. The Ce-based supports were calcined at different temperatures (750 and 900 degrees C) and the catalysts were reduced at 750 degrees C or 500 degrees C. Tuning the calcination temperature allowed for an increase in the support surface area, resulting in well-dispersed Rh species that provided a high reducibility for both the metal active phase and the Ce-based support. This allowed for an increase in methane conversion under different conditions of contact time and pressure and the outperformance of the other catalysts. The higher activity was related to well-dispersed Rh species interacting with the support that provided a high concentration of surface OH* on the Ce-based support and increased methane dissociation. This anticipated the occurrence and the extent of steam reforming over the catalytic bed, producing a smoother thermal profile