Synthesis, characterization and DFT study of new azaborinine compounds

In the framework of this thesis, a wide-ranging study of azaborinine derivatives was conducted, with a particular interest towards 9,10-B,N-phenanthrenes, holding an isosteric B-N unit in the place of a C=C bond and incorporating a B-C chiral axis. For this purpose, a preliminary theoretical study for four compounds of this class was carried out: conformational analysis and rotational energy barriers, UV-Vis absorption and fluorescence emission as well as theoretical ECD spectra of the atropisomeric structures were calculated by means of DFT and TD-DFT. An experimental attempt to synthesize and characterize another derivative of this class followed. The main synthetic concept evolved around the obtention of anti-aromatic 9-borafluorene precursors by boron-tin exchange from the reaction of a 9-stannafluorene derivative with boron reagents, followed by an aromaticity-driven ring-opening reaction of these borafluorene precursors with an organic azide. Several approaches based on similar previous works were reproduced to the closest possible version, as no absolutely inert conditions could be achieved, but the expected products were not formed; in one case, an open structure was obtained instead, for the formation of which a mechanism was proposed.