SYNTHESIS AND REACTIVITY OF N-CONTAINING HETEROCYCLES THROUGH CATALYTIC SYSTEMS.

N-containing heterocycles are the more represented in natural products and drugs. Our research has been focused on various aspects of heterocycles synthesis and reactivity. For this purpose we use transition metals catalysis, among which Pd has a central role due to the existence of different and easily and interconvertible oxidation states, Pd(0), Pd(II) and Pd(IV). For the arylation reaction electron poor aryl derivatives are problematic substrates, but we are successful in apply an intramolecular Pd(0) catalyzed reaction, in ligand free conditions, to synthesize azine and diazine polyheterocycles. Following our study on the reactivity and functionalization of indole derivatives we focus our attention on the amination reaction applied to the heterocycle indoline. The indoline skeleton is a ubiquitous scaffold found in many biologically active alkaloids and pharmaceutically active compounds, useful even as chiral auxiliary and for advanced materials. We selected the best conditions to functionalize this heterocycle at the nitrogen atom; then we find environmental friendly conditions using a solvent-free, microwaves assisted, reaction method and substantially reducing the catalyst load. Further to this we demonstrate the possibility of making Pd(0)-catalyzed amination reactions even in ligand-free conditions. In the third part we study a new synthesis of tetracyclic 1,4-Benzodiazepin-5-ones. The exploited reactions are Pd(0) catalyzed heterocyclization on imidazolidinones allenylamide followed by 1,3-dipolar cycloaddition. In the last step of the synthesis we obtain an unexpected total diasteroselectivity so we make a DFT and HF computational study that justify our results also thanks to the use of the recent QTAIM theory. In the last part we use Pd(II) and Au(III)-catalyzed reactions to realize C-H activation reaction. Starting from isoxazol-5-ones we obtain a solvent based regioselectivity in the alkenylation with acrylates or propiolates. The use of Pd(II)/O2 catalysis with acrylates lead to regioselectivity but with low yield; Au(III) catalysis with propiolates gives better yield and shows a complete regioselectivity.