Titolo della tesi: SYNTHESIS OF POLYCYCLIC COMPOUNDS OF BIOLOGICAL INTEREST THROUGH TRANSITION METAL-CATALYZED AND METAL-FREE APPROACHES
Heterocycles and polycyclic molecular structures represent a privileged class of organic compounds because they are ubiquitous structural units in a broad variety of biologically and pharmacologically relevant natural products, medicinal molecules, and functional materials. In this context, the synthesis and functionalization of polycycles and heterocycles have become a steadily increasing driving force both in academia and industry. Transition-metal catalysis has traditionally been considered a strong pillar of catalysis and has mostly dominated the field of organic synthesis, establishing it as an essential tool in the synthesis of polycycles. Transition metals' feature to move between different oxidation states and form complexes with reagents in a catalytic cycle allows us to achieve unprecedented molecular transformations. Moreover, the reactivity and selectivity of these metal complexes can be fine-tuned according to the requirement of the catalytic process with the assistance of different factors, such as the steric and electronic nature of metal-coordinated ligands and counterions. In this way, these processes are in general highly efficient and hold tremendous potential for the development of new synthetic methodologies. The drawback of employing metals as catalysts is the purification of the synthesized compounds and in disposal of them from the reaction mixture. For this reason, another interesting tool that received a great deal of attention to easily obtain heterocyclic structure consists of the Diels-Alder reaction and dienes chemistry: over the past few years, this branch of modern chemistry has found applications in total synthesis as well as organic chemistry.
Thus, the aim of this PhD thesis is to provide insight into different strategies and methodologies developed in the last three years for the synthesis of biologically interesting polycycles, with a focus on Pd, Au and Cu-catalyzed reactions and diene chemistry as powerful and versatile tools for the construction and functionalization of important heterocycles.