ETD

• alkynylation
• alkynylimidazoles
• dehydrogenative alkynylation
• dehydrogenative cross-coupling

Alkynylated heteroarenes, and in particular alkynylazoles, represent a recurring structural motif found in bioactive natural products, pharmaceuticals, and organic materials. These compounds are of great importance either as building blocks or synthetic intermediates and have become increasingly attractive for synthetic organic chemists. In this Thesis, an efficient strategy for the selective C-2 alkynylation of the imidazole ring by cross-dehydrogenative coupling reaction was developed.
Since in the last few years there has been great interest in the construction and investigation of fluorophores featuring a π-conjugated backbone, the developed strategy has been employed for the synthesis of imidazole-based chromophores end-capped with electron-donating (EDG) and electron-acceptor (EWG) groups (“push-pull” systems). Some 2-(arylethynyl)-4,5-bisarylimidazoles, which are potential “Y-shaped” chromophores, were prepared and their main fluorescence properties, such as absorption and emission maxima, Stoke’s shift, and quantum yield, were evaluated.