Beyond simple proton transfer processes: domino reactions between 4-substituted indoles and nitroethene as a new gateway to ergot alkaloids

The multimodal biology activity of ergot alkaloids is known by humankind since middle ages. Synthetically modified ergot alkaloids are used for the treatment of various medical conditions. Despite the great progress in organic syntheses, the total synthesis of ergot alkaloids remains a great challenge due to the complexity of their polycyclic structure with multiple stereogenic centres. This project has developed a new domino reaction between indoles bearing a Michael acceptor at the 4 position and nitroethene, leading to potential ergot alkaloid precursors in highly enantioenriched form. The reaction was optimised and applied to a large variety of substrate with good results. Even if unfortunately all attempts to further modify the obtained polycyclic structure failed, it was found a reaction able to produce the diastereoisomer of the polycyclic product in excellent yields. The compounds synthetized were characterized by NMR and ESIMS analysis confirming the structure and their enantiomeric excess was determined by chiral stationary phase HPLC. The mechanism of the reaction was evaluated by DFT calculations, showing the formation of a key bicoordinated nitronate intermediate, and fully accounting for the results observed with all substrates. The relative and absolute configuration of the adducts were determined by a combination of NMR, ECD and computational methods.

Traduzione del primo canto dell'inferno dantesco in arabo

In this thesis, I have chosen to translate from Italian into Arabic Canto I of the Inferno, from Dante Alighieri’s epic poem the Divine Comedy (La Divina Commedia) because it’s a masterpiece in both Italian and world literature. Also I have selected it for its artistic value and the universal themes that it depicts. In fact, my purpose in translating this great work into Arabic is to extol the cultural and universal aspects that can be common to human beings everywhere. My paper is written in Arabic and has six sections: A brief introduction on Dante’s life, an introduction to the Divine Comedy, a summary of Canto 1 of the Inferno and its analysis, Canto I of the Inferno in Italian, its translation into Arabic and finally a comment on the translation. The first part -a summary of Dante’s life was presented. The second part of my paper is an introduction to the Divine Comedy, the allegorical epic poem, consisting of three parts: The Inferno (Hell), Purgatorio (Purgatory), and Paradiso (Paradise). The third part is a summary and analysis of Canto 1 of the Inferno, Dante’s most renowned verses. The analysis of Canto highlights the everlasting conflict of man– sinning and giving in to temptation but then trying to repent and search for his soul’s salvation. He reflects on sin, existence, truth, God, love and salvation in his struggle through the dark and gloomy forest which symbolizes conflict and temptations man may succumb to. The influence of Christianity and the Middle ages here shows his commitment to religion and faith. Moreover, his meeting of Virgil, who guides him to the mountain during his journey to salvation, reflects the positive impact of Virgil’s philosophy on Dante. The fourth part presents the Italian version of Canto 1 of the Inferno. The fifth section of my paper is the translation of Canto 1 of the Inferno from Italian to Arabic. Translating an excerpt of Dante’s masterpiece was not an easy task: I had to consult several critique texts besides the Italian source text with explanations, and also some English versions to overcome any translation difficulties. As a student of translation, my goal was to be faithful in relaying to the Arabic audience the authenticity of Dante’s work, his themes, passions and aesthetic style. Finally, I present a conclusion including a comment on the translation and the bibliography of the sources I have consulted.