Asymmetric Organocatalysis-A Powerful Technology Platform for Academia and Industry: Pregabalin as a Case Study

Enantioselective organocatalysis has quickly established itself as the third pillar of asymmetric catalysis. It is a powerful technology platform, and it has a tremendous impact in both academic and industrial settings. By focusing on pregabalin, as a case study, this Perspective aims to show how a process amenable to industry of a simple chiral molecule can be tackled in several different ways using organocatalysis

Asymmetric Organocatalysis Accelerated via Self-Assembled Minimal Structures

Self-assembling minimalistic peptides embedded with an organocatalytic moiety were designed. By controlling the formation of fibrils via external intervention, it was shown that the activation is accelerated when the organocatalyst is in its supramolecular state. The effect of the accelerated catalysis was demonstrated in a Michael benchmark reaction

Continuous-Flow Synthesis of Arylthio-Cyclopropyl Carbonyl Compounds

The straightforward, continuous-flow synthesis of cyclopropyl carbaldehydes and ketones has been developed starting from 2-hydroxycyclobutanones and aryl thiols. This acid-catalyzed mediated procedure allows access to the multigram and easily scalable synthesis of cyclopropyl adducts under mild conditions, using reusable Amberlyst-35 as a catalyst. The resins, suitably ground and used for filling steel columns, have been characterized via TGA, ATR, SEM and BET analyses to describe the physical-chemical properties of the packed bed and the continuous-flow system in detail. To highlight the synthetic versatility of the arylthiocyclopropyl carbonyl compounds, a series of selective oxidation reactions have been performed to access sulfoxide and sulfone carbaldehyde cyclopropanes, oxiranes and carboxylic acid derivatives

Studio della combustione eterogenea di miscele alluminio-aria

In questo elaborato di tesi si è voluto analizzare il comportamento della fiamma nei casi di combustione omogenea ed eterogenea. Sono stati analizzati gli aspetti della combustione dal punto di vista della temperatura adiabatica di fiamma e della sua velocità laminare. Questo tipo di analisi è stato fatto utilizzando un software di simulazione numerica come Ansys Fluent. Per la combustione omogenea è stato studiato il caso della combustione del metano in aria, mettendo a confronto i risultati ottenuti con i dati presenti in letteratura. Nel caso di combustione eterogenea invece è stato studiato il caso della combustione tra una polvere di alluminio e l'aria, con le particelle solide dal diametro medio di 10 micron. Si è analizzata nel dettaglio la combustione solido-gas, considerando anche il tempo di combustione della singola particella. Oltre alla temperatura adiabatica e alla velocità laminare di fiamma sono state analizzate anche la miscelazione tra le due fasi e la frazione di volume della fase solida. Abbiamo notato che i valori di temperatura adiabatica e velocità laminare della fiamma nel caso di combustione alluminio-aria non si discostano molto dal caso di metano-aria, questo rende l’alluminio un importante vettore di energia ed un potenziale sostituto dei combustibili fossili, in grado di ridurre le emissioni di gas serra, come l’anidride carbonica

Asymmetric aminocatalysis: a modern strategy for molecules, challenges and life

The studies conducted during my Phd thesis were focused on two different directions: 1. In one case we tried to face some long standing problems of the asymmetric aminocatalysis as the activation of encumbered carbonyl compounds and the control of the diastereoisomeric ratio in the diastero- and enantioselective construction of all carbon substituted quaternary stereocenters adjacent a tertiary one. In this section (Challenges) was described the asymmetric aziridination of ,-unsaturated ketones, the activation of ,-unsaturated -branched aldehydes and the Michael addition of oxindoles to enals and enones. For the activation via iminium ion formation of sterically demanding substrates, as ,-unsaturated ketones and ,-unsaturated -branched aldehydes, we exploited a chiral primary amine in order to overcome the problem of the iminium ion formation between the catalyst and encumbered carbonylic componds. For the control of diastereoisomeric ratio in the diastero- and enantioselective construction of all carbon substituted quaternary stereocenters adjacent a tertiary one we envisaged that a suitable strategy was the Michael addition to 3 substituted oxindoles to enals activated via LUMO-lowering catalysis. In this synthetic protocol we designed a new bifunctional catalyst with an amine moiety for activate the aldehyde and a tioureidic fragment for direct the approach of the oxindole. This part of the thesis (Challenges) could be considered pure basic research, where the solution of the synthetic problem was the goal itself of the research. 2. In the other hand (Molecules) we applied our knowledge about the carbonylic compounds activation and about cascade reaction to the synthesis of three new classes of spirooxindole in enantiopure form. The construction of libraries of these bioactive compounds represented a scientific bridge between medicinal chemistry or biology and the asymmetric catalysis