The research work reported in this Thesis was held along two main lines of research. The first and main line of research is about the synthesis of heteroaromatic compounds with increasing steric hindrance, with the aim of preparing stable atropisomers. The main tools used for the study of these dynamic systems, as described in the Introduction, are DNMR, coupled with line shape simulation and DFT calculations, aimed to the conformational analysis for the prediction of the geometries and energy barriers to the trasition states. This techniques have been applied to the research projects about: • atropisomers of arylmaleimides; • atropisomers of 4-arylpyrazolo[3,4-b]pyridines; • study of the intramolecular NO2/CO interaction in solution; • study on 2-arylpyridines. Parallel to the main project, in collaboration with other groups, the research line about determination of the absolute configuration was followed. The products, deriving form organocatalytic reactions, in many cases couldn’t be analyzed by means of X-Ray diffraction, making necessary the development of a protocol based on spectroscopic methodologies: NMR, circular dichroism and computational tools (DFT, TD-DFT) have been implemented in this scope. In this Thesis are reported the determination of the absolute configuration of: • substituted 1,2,3,4-tetrahydroquinolines; • compounds from enantioselective Friedel-Crafts alkylation-acetalization cascade of naphthols with α,β-unsaturated cyclic ketones; • substituted 3,4-annulated indoles.

This doctoral thesis deals with the development of novel organocatalytic strategies for asymmetric transformation. The intrinsic versatility of organocatalysis and the use of different activation modes have been exploited to achieve new catalytic enantioselective processes, towards the synthesis of biologically relevant scaffolds. The most investigated organocatalytic system have been those based on H-bond interaction (such as chiral thioureas or phosphoric acids) as well as the ones based on aminocatalysis. Despite conceptually distinct, the transformations detailed in this Thesis are linked together by simple and recurring modes of activation, induction and reactivity, promoted by the catalysts employed. The chemical diversity of the challenges encountered allows to get a precious overall view on organocatalysis, highlighting that enormous chemical diversity can be created by judicious choice of select catalyst.

In this thesis the potential risks associated to the application of biochar in soil as well the stability of biochar were investigated. The study was focused on the potential risks arising from the occurrence of polycyclic aromatic hydrocarbons (PAHs) in biochar. An analytical method was developed for the determination of the 16 USEPA-PAHs in the original biochar and soil containing biochar. The method was successfully validated with a certified reference material for the soil matrix and compared with methods in use in other laboratories during a laboratory exercise within the EU-COST TD1107. The concentration of 16 USEPA-PAHs along with the 15 EU-PAHs, priority hazardous substances in food, was determined in a suite of currently available biochars for agricultural field applications derived from a variety of parent materials and pyrolysis conditions. Biochars analyzed contained the USEPA and some of the EU-PAHs at detectable levels ranging from 1.2 to 19 µg g-1. This method allowed investigating changes in PAH content and distribution in a four years study following biochar addition in soils in a vineyard (CNR-IBIMET). The results showed that biochar addition determined an increase of the amount of PAHs. However, the levels of PAHs in the soil remained within the maximum acceptable concentration for European countries. The vineyard soil performed by CNR-IBIMET was exploited to study the environmental stability of biochar and its impact on soil organic carbon. The stability of biochar was investigated by analytical pyrolysis (Py-GC-MS) and pyrolysis in the presence of hydrogen (HyPy). The findings showed that biochar amendment significantly influence soil stable carbon fraction concentration during the incubation period. Moreover, HyPy and Py-GC-MS were applied to biochars deriving from three different feedstock at two different pyrolysis temperatures. The results evidenced the influence of feedstock type and pyrolysis conditions on the degree of carbonisation.

This thesis work aims to develop original analytical methods for the determination of drugs with a potential for abuse, for the analysis of substances used in the pharmacological treatment of drug addiction in biological samples and for the monitoring of potentially toxic compounds added to street drugs. In fact reliable analytical techniques can play an important role in this setting. They can be employed to reveal drug intake, allowing the identification of drug users and to assess drug blood levels, assisting physicians in the management of the treatment. Pharmacological therapy needs to be carefully monitored indeed in order to optimize the dose scheduling according to the specific needs of the patient and to discourage improper use of the medication. In particular, different methods have been developed for the detection of gamma-hydroxybutiric acid (GHB), prescribed for the treatment of alcohol addiction, of glucocorticoids, one of the most abused pharmaceutical class to enhance sport performance and of adulterants, pharmacologically active compounds added to illicit drugs for recreational purposes. All the presented methods are based on capillary electrophoresis (CE) and high performance liquid chromatography (HPLC) coupled to various detectors (diode array detector, mass spectrometer). Biological samples pre-treatment was carried out using different extraction techniques, liquid-liquid extraction (LLE) and solid phase extraction (SPE). Different matrices have been considered: human plasma, dried blood spots, human urine, simulated street drugs. These developed analytical methods are individually described and discussed in this thesis work.

This research intends to explore the mechanism behind the transformation of ethanol over basic and acid/base catalysts. The approach used was first to explore in depth the role of the MgO which is a common component of both reactions (Lebedev and Guerbet) and then to study the incorporation of Si ion and the effect on the acid/base properties of the resulting materials. Moreover, the addition of a dopant with acid/dehydrogenating properties was also explored. Further on, several catalysts were tested under the usual conditions for this reaction and characterization was made in order to understand their particular behavior. An important tool in this research was the in-situ infrared diffuse reflectance spectroscopy (DRIFTS) coupled with mass spectrometry (MS) due to the possibility that it offers to study what occurs on the catalysts surface under real working conditions. This study allowed to gain new insights on the mechanism behind the catalytic upgrading of ethanol on basic and acid/base mixed oxides, giving an alternative view of the mechanism for the Lebedev and Guerbet reactions that permitted us to discard the key role of the generally accepted intermediates and helped to explain several experimental findings not clear before.

The present study is focused on the development and improvement of sustainable catalytic processes for the synthesis of organic carbonates. In particular, the condensation reaction between carbon dioxide and several alcohols and diols has been investigated using a new generation of mesoporous nanosilicas functionalized by the insertion of amino groups on the catalyst surface. This reaction were performed in a high-pressure batch vessel (autoclave). Moreover, the carbonate interchange reaction (CIR) of the simplest linear organic carbonate, dimethyl carbonate (DMC) with several alcohols has been implemented by means of a new lab-scale reactive distillation system. In this new system, the distilled mixture is continuously passed over molecular sieves able to promote a selective adsorption of methanol (co-product of the reactions) while DMC is continuously refluxed back into the reaction batch. In this way, we were able to promote an efficient shift of the reaction equilibria toward the formation of the desired products. This system allowed us to achieve up to 90% isolated yield of pyrocatechol carbonate (PCC), a new and previously scarcely investigated carbonate. The PCC has been used as a new and more efficient carbonate source for the selective synthesis of symmetric carbonates and for the synthesis of glycerol carbonate (GlyC). GlyC has been also used as glycidol intermediate, for the condensation reaction with catechol in order to obtain the efficient synthesis of 2-hydroxymethy-1,4-benzodioxane (HMB) an important intermediate for the pharma industry. Finally, some of the synthesized carbonates were tested for the gas-phase phenol alkylation showing an interesting reactivity that could be properly modulated by changing the reaction conditions and the catalyst acid-base properties.

This thesis describes the research focused on the study of different electrode supports modified with layered double hydroxides (LDHs) on Co or Ni as M(II) and Al or Fe as M(III) or conducting polymers for energy applications. The LDHs were characterized by electrochemical techniques, FE-SEM, XRD, XPS and XAS. Glassy carbon and Pt electrodes modified with electrosynthesized LDHs were employed in order to investigate their performances as oxygen evolution reaction catalysts and as pseudocapacitor materials. Moreover, the electrochemical synthesis of poly(3,4-ethylenedioxythiophene) (PEDOT) on indium tin oxide (ITO) was carried out in order to exploit an alternative route to fabricate bulk heterojunction solar cells with similar performances but less expensive than those obtained by casting. The photoactive layer was composed by [6,6]-phenyl-C61 butyric acid methyl ester (PCBM) as electron acceptor, while as donor polymer it was employed either the commonly employed rr-poly(3-hexylthiophene) or a polythiophene copolymer, functionalized with a porphyrin derivative in order to improve the absorption in the UV/Vis region. In the second part of the thesis, the LDHs modified electrodes were employed for sensing, taking into account the electrocatalytic oxidation of sugars. Ni/Al or Ni/Fe LDHs were studied with the aim to investigate again the effect of Fe on the electrocatalysis. LDHs prepared both by chemical and electrochemical syntheses were employed with the aim of studying the effect of the order degree on the LDHs performance since this parameter is crucial to improve the “sensing” properties. Furthermore, a sensor for the amperometric detection of sugars in flow systems, based on Co/Al LDH electrosynthesized on Pt electrodes, was developed. A mixture of sugars was submitted to high performance anion chromatography with amperometric detection, using the modified electrode as the working electrode. Moreover, to assess the applicability of the device glucose, fructose, and sucrose content in real samples were successfully determined.

Nanomaterials have a tremendously increasing importance in our daily lives but their world is extremely wide. The main aim of this work is to implement the knowledge about these materials, focusing in particular on some of the nano allotropic forms of Carbon. This precise choice is consequence of their extreme versatility and promising properties for electronic, energetic and biological applications, which can be further improved with doping or functionalization. In the first part of my work I introduced nanotechnology and nanomaterials, highlighting their importance, recent developments and applications, trying to focus on the importance of electrochemistry in the study of such a field. Electrochemistry, in fact, through the investigation of fundamental electronic processes can exploit electrical and catalytic processes of nanomaterials and become an interface between nano and macroscopic world. The second chapter of this thesis is dedicated to the investigation of a new synthetic pathway for bottom up nano-Graphene production, using polyaromatic hydrocarbons precursors. The chemical and morphological analysis of the obtained deposits gives encouraging results about the proficient production of Carbon-base nano-assemblies. The third chapter is dedicated to the study and application of nanocarbons for energy production with particular attention to the incoming environmental problem. The objects of my study were Nitrogen-doped Graphene, as an alternative to metal catalysts for Oxygen reduction reaction (ORR), and a Bodipy chromophore coupled with a Fullerene, as an efficient system for photoelectrochemical conversion. The results obtained until now in the study of Carbon-based nanomaterials represent a good reason to further investigate their behaviour, properties and possible applications and I hope this thesis is a contribution to such a complex topic.

This thesis describes the synthesis, the conformational analysis and the applications of pseudopetide foldamers containing the 4-carboxy-5-methyl-oxazolidin-2-one moiety or the pyroglutamic acid unit. These molecules mimic a proline group and have been applied to the formation of oligomers that in solution may easily adopt a stable secondary structure. These pseudoprolines block the peptide bond always in the trans conformation, because the nitrogen atom of the ring is adjacent to both an exocyclic and an endocyclic carbonyl group, forcing them to a strict trans conformation. This remarkable property induces a constrain in the pseudopeptide chain that may help the formation of supramolecular materials. Following a simple methodology we have efficiently prepared a variety of foldamers, whose proprieties may be changed choosing different amino acids, thus providing several secondary structures.

During the PhD Luca Mengozzi studied reactions involving carbocations or carbocationic intermediates to develop new synthetic methodologies, and a new generation of quantum cellular automata (QCA) candidates in the context of the European Project Molarnet. Concerning the development of new asymmetric methodologies, he studied in detail the stereoselective alkylation of aldehydes with isoquinolinium and quinolinium ions generated in situ. These reactions were promoted by chiral secondary amine catalysts and no metals are needed. The first alkylation of acyl isoquinolinium ions with aldehydes was reported and it was applied to the first enantioselective synthesis of 13-alkyl tetrahydroprotoberberine alkaloids. Preliminary tests on resistant tumor cell lines performed by prof. Calonghi revealed promising cytotoxic activities. An asymmetric Pictet Spengler reaction to access 1-allyl isoquinolines was also reported. He studied the activation of carboxylic acids and their alkylation with stable carbenium ions promoted by chiral isothioureas and the development of the first photocatalytic alkylation of aldehydes promoted by iron photosensitizers. He spent five months as a visiting PhD student in Prof. Pericás Research group at ICIQ, Tarragona, Spain. During this period he studied the use of flow chemistry techniques for the synthesis of antiviral agent (-)-oseltamivir. In particular he studied the use of supported organocatalsyts in the enantiodetermining step of the synthetic pathway. QCA are a new paradigm for molecular computation and he worked on the synthesis of new candidates applying the knowledge of the research group on SN1 reactions. Through this strategy a new class of ferrocene guanines conjugates, ferrocene porphyrins, and ferrocene containing aluminium salophen complexes were obtained. The study of their properties on different surfaces that revealed the formation of interesting self-assembled monolayers for both salophen complexes and porphyrins. One paper was published and three are in preparation with our Molarnet partners.