RESUMO
Starting from commercially available amino acid derivatives, two novel families of chiral ionic liquids having either a thiazolinium or an imidazolium cation were prepared by simple and straightforward procedures in good overall yields. The properties of these new salts can be finely tuned by careful selection of the anion and the cation.
Assuntos
Aminoácidos/química , Imidazóis/síntese química , Líquidos Iônicos/síntese química , Tiazóis/síntese química , Imidazóis/química , Líquidos Iônicos/química , Tiazóis/químicaRESUMO
This is not breaking news: copper acetylides, readily available polymeric rock-stable solids, have been known for more than a century to be unreactive species and piteous nucleophiles. This lack of reactivity actually makes them ideal alkyne transfer reagents that can be easily activated under mild oxidizing conditions. When treated with molecular oxygen in the presence of simple chelating nitrogen ligands such as TMEDA, phenanthroline or imidazole derivatives, they are smoothly oxidized to highly electrophilic species that formally behave like acetylenic carbocations and can therefore be used for the mild and practical alkynylation of a wide range of nitrogen, phosphorus and carbon nucleophiles.