During my PhD I was involved in many studies concerning the nucleophilic (SNAr) and electrophilic (SEAr) aromatic substitution reactions. My research activity was focused on the study of different electrophile/nucleophile combinations between strongly activated species, with the purpose to investigate on their reactivity, to detect new intermediates of the aromatic substitution reaction and to obtain new higly conjugated structures bearing contemporaneously electron donor and acceptor moieties on the same unit for application in different fields. Different reactions between both neutral or charged electrophilic and nucleophilic species were performed and from their combinations new products for applications in different fields (e.g. medicine, biology and materials) were obtained and new intermediates of the aromatic substitution reactions [e.g. Wheland (W), Meisenheimer (M), and even Wheland-Meisenheimer (WM)], were detected and characterized, mainly using NMR spectroscopic techniques. In particular the involved nucleophilic species were: tri- and diaminobenzene derivatives, trihydroxybenzene, trimethoxybenzene, anisole derivatives and aminothiazole derivatives; whereas the selected electrophilic species were: aryldiazonium ions, benzofuroxan and benzofurazan derivatives, thiophene derivatives and benzhydrylium ions. Furthermore, the last year of my PhD course, I spent a period in the Department of Chemistry, Ludwig-Maximilians-University of Munich, in collaboration with Prof. Herbert Mayr’s group, with the aim to investigate on the nucleophilic reactivities of di- and triaminobenzene derivatives performing their combination with different reference electrophiles, selected from the Mayr’s reactivity scales.

Questa tesi è mirata ad essere un lavoro che racchiude alcuni dei vari aspetti rilevanti che collegano la Green Chemistry alla sostenibilità ambientale. La tesi riguarda lo sviluppo sostenibile attraverso capitoli che concorrono alla progettazione di processi chimici eco-compatibili innovativi e approcci verdi per ridurre al minimo e/o rimediare l'inquinamento ambientale. In questo contesto, il mio progetto di dottorato ha affrontato tre temi principali: 1. Progettazione, sintesi e caratterizzazione di nuove molecole di tensioattivo che impiegano materie prime rinnovabili, acido itaconico e ammine lipofile, come materiali di partenza; il Capitolo 2 descrive questo argomento. 2. Sviluppo di una procedura sostenibile finalizzata alla sintesi multicomponente a cascata di biarilcalconi in acqua pura o in condizioni di catalisi micellare; in quest'ultimo caso, uno dei tensioattivi precedentemente sintetizzati è stato ampiamente impiegato; il Capitolo 5 descrive questo argomento. Capitolo 3 e Capitolo 4 descrivono il contesto scientifico e le innovazioni più importanti che hanno aperto la strada a i risultati conseguiti durante il 2 ° anno del corso di dottorato; il primo è una panoramica sull'uso dell'acqua come solvente per reazioni organiche; il secondo è una panoramica sulle reazioni di cross-coupling e lo sfruttamento in questo contesto della catalisi micellare. 3. Progettazione, sintesi e impiego di ligandi di tipo fenantrolinico deuterati per l'ossidazione aerobica palladio catalizzata del metil-glucoside, consentendo un elevato miglioramento della prestazione in questa reazione impegnativa; il Capitolo 7 raccoglie i risultati ottenuti, mentre il capitolo 6 riassume i più importanti progressi ottenuti negli ultimi anni nelle ossidazioni aerobiche di alcoli palladio-catalizzate. / This thesis is intended to be a work that encompasses some of the various relevant aspects linking the Green Chemistry practice to environmental sustainability. The thesis covers sustainable development through chapters that contribute to the design of novel environmentally benign chemical processes and green approaches to minimize and/or remediate environmental pollution. In this context, my PhD project has faced three main topics: 1. Design, synthesis and characterization of new surfactant molecules employing renewable feedstocks, itaconic acid and fatty amines, as starting materials; Chapter 2 describes this topic. 2. Development of a sustainable procedure aimed to the multicomponent cascade synthesis of biaryl-based chalcones in pure water or under micellar catalysis conditions; in the latter case, one of the surfactants previously synthesized has been widely employed; Chapter 5 describes this topic. Chapter 3 and Chapter 4 describe the scientific context and the most important innovations that have paved the way to the results achieved during the 2nd year of PhD course; the former is an overview on the use of water as solvent for organic reactions; the latter is an overview on cross-coupling reactions and the exploitation in this context of micellar catalysis. 3. Design, synthesis and exploitation of deuterated phenanthroline-type ligands for the aerobic palladium-catalyzed oxidation of methyl glucoside, allowing a high performance improvement in this challenging reaction; Chapter 7 collects the obtained results, while Chapter 6 summarizes the most important advances obtained in the last years in the palladium-catalyzed aerobic oxidations of alcohols.

During the last fifteen years organocatalysis emerged as a powerful tool for the enantioselective functionalization of the most different organic molecules. Both C-C and C-heteroatom bonds can be formed in an enantioselective fashion using many types of catalyst and the field is always growing. Many kind of chiral catalysts have emerged as privileged, but among them Proline, cinchona alkaloids, BINOL, and their derivatives showed to be particularly useful chiral scaffolds. This thesis, after a short presentation of many organocatalysts and activation modes, focuses mainly on cinchona alkaloid derived primary amines and BINOL derived chiral Brønsted acids, describing their properties and applications. Then, in the experimental part, these compounds are used for the catalysis of new transformations. The enantioselective Friedel-Crafts alkylation of cyclic enones with naphthols using cinchona alkaloid derived primary amines as catalysts is presented and discussed. The results of this work were very good and this resulted also in a publication. The same catalysts are then used to accomplish the enantioselective addition of indoles to cyclic enones. Many catalysts in combination with many acids as co-catalysts were tried and the reaction was fully studied. Selective N-alkylation was obtained in many cases, in combination with quite good to good enantioselectivities. Also other kind of catalysis were tried for this reaction, with interesting results. Another aza-Michael reaction between OH-free hydroxylamines and nitrostyrene using cinchona alkaloid derived thioureas is briefly discussed. Then our attention focused on Brønsted acid catalyzed transformations. With this regard, the Prins cyclization, a reaction never accomplished in an enantioselective fashion until now, is presented and developed. The results obtained are promising. In the last part of this thesis the work carried out abroad is presented. In Prof. Rueping laboratories, an enantioselective Nazarov cyclization using cooperative catalysis and the enantioselective desymmetrization of meso-hydrobenzoin catalyzed by Brønsted acid were studied.

During the course of my Ph.D. in the laboratories directed by Prof. Alfredo Ricci at the Department of Organic Chemistry “A. Mangini” of the University of Bologna, I was involved in the study and the application of a number of organocatalytic systems, all coming from the natural chiral pool. The first part of this thesis will be devoted to new homogeneous organocatalytic reactions promoted by Cinchona alkaloid-based organocatalysts. Quinine based catalysts were found to be a very effective catalyst for Diels-Alder reactions involving 3-vinylindoles. Excellent results in terms of yields and enantioselectivities were achieved, outlining also a remarkable organocatalytic operational mode mimicking enzymatic catalysis. The same reaction with 2-vinylindoles showed a completely different behaviour resulting in an unusual resolution-type process. The asymmetric formal [3+2] cycloaddition with in situ generated N-carbamoyl nitrones using Cinchona-derived quaternary ammonium salts as versatile catalysts under phase transfer conditions, outlines another application in organocatalysis of this class of alkaloids. During the seven months stage in the Prof. Helma Wennemers’ group at the Department of Chemistry of the University of Basel (Switzerland) I have been involved in organocatalysis promoted by oligopeptides. My contribution regarded the 1,4-addition reaction of aldehydes to nitroolefins. In the work performed at the Department of Organic Chemistry “A. Mangini” of the University of Bologna, in collaboration with the ‘Institut Charles Gerhardt-Montpellier, of Montpellier (France) the possibility of performing for the first time heterogeneous organocatalysis by using a natural polysaccharide biopolymer as the source of chirality was disclosed. With chitosan, derived from deacetylation of chitin, a highly enantioselective heterogeneous organocatalytic aldol reaction could be performed. The use of an eco-friendly medium such as water, the recyclability of the catalytic specie and the renewable nature of the polysaccharide are assets of this new approach in organocatalysis and open interesting perspectives for the use of biopolymers.

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