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Deep Eutectic Solvents (DESs) have appeared in recent years as an appealing alternative to classical organic solvents, due to their valuable environmental properties. In addition, these compounds, formed by the combination of one hydrogen bond donor with a hydrogen bond acceptor at a defined stoichiometric ratio, present other valuable activities not only as a reaction medium. DESs can also be employed as catalysts through hydrogen-bond interactions in different chemical transformations, thus substituting hazardous reagents and solvents. The search for novel and more environmentally friendly catalysts is an area of interest of pharmaceutical chemists, and therefore, the efforts made in the application of DESs as catalysts in the synthesis of APIs or its precursors are described, focusing mainly on condensations, nucleophilic additions to carbonyl moieties, and multicomponent reactions.

El objetivo de este Trabajo de Fin de Grado consiste en la identificación automática de las denominadas oraciones yuxtapuestas, y su posterior transformación, puesto que presentan una problemática para personas con dificultades de compresión lectora, según establece la Metodología de Lectura Fácil. Este tipo de problemática es una de las directrices que marca dicha metodología para la creación de textos generales más accesibles y fáciles de entender. Con tal fin, se ha creado un corpus especializado que cuenta con un amplio número de oraciones yuxtapuestas etiquetadas. Para el análisis de este corpus, y, por ende, el desarrollo de la herramienta se ha llevado a desarrollado un algoritmo capaz de detectar dichas oraciones, apoyado por un modelo de clasificación binaria desarrollado principalmente con este fin gracias a la librería de Python spaCy, que ha facilitado el etiquetado gramatical de las oraciones que componen el corpus. Una vez detectada la yuxtaposición de las oraciones, se realizan una serie de transformaciones sobre estas para dotarlas de nexos o conectores discursivos, enriqueciendo las oraciones de mayor contenido sintáctico y gramatical, abordando así la problemática de compresión lectora descrita inicialmente. Por último, el trabajo se centra en evaluar cómo la oración original se compara con su versión transformada, permitiendo así analizar la eficacia de la herramienta. En definitiva, este Trabajo de Fin de Grado propone una solución innovadora para mejorar la compresión de textos en personas con dificultades lectoras. ABSTRACT The objective of this Final Degree Project is the automatic identification of the so-called juxtaposed sentences, and their subsequent transformation, since they present a problem for people with reading comprehension difficulties, according to the Easy-to-Read (E2R) Methodology. This type of problem is one of the guidelines established by this methodology for the creation of general texts that are more accessible and easier

Enzymes are crucial for the emergence and sustenance of life on earth. How they became catalytically active during their evolution is still an open question. Two opposite explanations are plausible: acquiring a mechanism in a series of discrete steps or all at once in a single evolutionary event. Here, we use molecular phylogeny, ancestral sequence reconstruction, and biochemical characterization to follow the evolution of a specialized group of flavoprotein monooxygenases, the bacterial Baeyer-Villiger monooxygenases (BVMOs). These enzymes catalyze an intricate chemical reaction relying on three different elements: a reduced nicotinamide cofactor, dioxygen, and a substrate. Characterization of ancestral BVMOs shows that the catalytic mechanism evolved in a series of steps starting from a FAD-binding protein and further acquiring reactivity and specificity toward each of the elements participating in the reaction. Together, the results of our work portray how an intrinsically complex catalytic mechanism emerged during evolution.

Asymmetric oxidation processes have constituted a valuable tool for the synthesis of active pharmaceutical ingredients (APIs), especially for the preparation of optically active sulfoxides, compounds with interesting biological properties. Classical approaches for these oxidative procedures usually require the application of non-sustainable conditions that employ hazardous reagents and solvents. In the last decades, chemists have tried to combine the preparation of valuable compounds of high yields and selectivities with the development of more sustainable protocols. To achieve this objective, greener solvents, reagents, and catalysts are employed, together with the use of novel chemical techniques such as flow catalysis or photocatalysis. The last efforts in the development of greener approaches for the preparation of APIs and their intermediates using oxidative procedure will be reviewed herein. Most of these approaches refer to biocatalytic methods, in which mild reaction conditions and reagents are employed, but other novel techniques such as photocatalysis will be described.

A highly enantioselective biocatalytic dynamic kinetic resolution (DKR) of 2-(quinoline-8-yl) 3-methylbenzaldehydes and 1-naphthaldehydes is described. The reaction proceeds by atroposelective carbonyl reduction catalyzed by commercial ketoreductases (KREDs), generally reaching high conversions and excellent enantiomeric excesses. Both atropoisomers of the final alcohols can be obtained by a proper selection of the biocatalyst. The DKR strategy relies in the racemization of the stereogenic axis that takes place thanks to a transient Lewis acid-base interaction (LABI) between the nitrogen in the quinoline and the carbonyl group.

The necessity of more sustainable conditions that follow the twelve principles of Green Chemistry have pushed researchers to the development of novel reagents, catalysts and solvents for greener asymmetric methodologies. Solvents are in general a fundamental part for developing organic processes, as well as for the separation and purification of the reaction products. By this reason, in the last years, the application of the so-called green solvents has emerged as a useful alternative to the classical organic solvents. These solvents must present some properties, such as a low vapor pressure and toxicity, high boiling point and biodegradability, and must be obtained from renewable sources. In the present revision, the recent application of these biobased solvents in the synthesis of optically active compounds employing different catalytic methodologies, including biocatalysis, organocatalysis and metal catalysis, will be analyzed to provide a novel tool for carrying out more ecofriendly organic processes.

A highly enantioselective biocatalytic dynamic kinetic resolution (DKR) of configurationally labile N-arylindole aldehydes is described. The DKR proceeds by atroposelective bioreduction of the carbonyl group catalyzed by commercial ketoreductases (KREDs), thus affording the corresponding axially chiral N-arylindole aminoalcohols, with excellent conversions and optical purities. The strategy relies on the racemization of the stereogenic axis that takes place thanks to a transient Lewis pair interaction between the NMe2 and the aldehyde groups. This protocol features a broad substrate scope under very mild conditions.