The Synthesis Of Some Trifluoroethylated Compounds

Fluorine-containing compounds are widely used in the fields of pharmaceuticals and agrochemicals. A large number of fluorine-containing drugs are already on the market. The synthesis of fluorinated or trifluoromethylated organic moleculars has been developed extensively in recent years. However, the synthesis of trifluoroethylated compounds containing nitrogen or phosphorus is very limited. In the thesis, building of trifluoroethylated compounds containing nitrogen or phosphorus from(4,4,4-trifluorobut-1-ynyl)arenes and diethyl 2,2,2-trifluoroethylphosphonate is studied.Part I: Copper-mediated cross-coupling reations of HCFC-123 with terminal alkynes are researched. The inert C-Cl bonds of HCFC-123 is activated by reductive low-cost copper species. A series of(4,4,4-trifluorobut-1-ynyl)arenes(Ar-C≡C-CH2CF3) are prepared. The Ru-catalyzed azide-alkyne cycloadditions(Ru AAC) of the above alkynes and various organic azides provide 5-trifluoroethylated-1,4,5-substitued-1,2,3-triazoles. The regioselectivities of triazoles are determined by X-ray single crystal diffraction. These reactions provide fully-substituted triazoles in good regioselectivity. This type of reaction can be extended to trifluoromethylthiolated alkynes(Ar-C≡C-SCF3), which can also achieve good regioselectivity.Part II: Large scale technology of copper-mediated cross-coupling reactions of HCFC-123 with phosphorous acid dialkyl esters is researched. The reaction is conducted in autoclave. The operation is simple, under mild conditions, and products are easy to separate. Product can be obtained in dozens of grams.In summary, the conversion of HCFC-123 was achieved by copper-mediated C-Cl activation. HCFCs are ozone-depleting and cause globe-warming effect. Our methodologies allow the conversion of HCFC-123 into all kinds of useful phosphorus or nitrogen-containing compounds, such as trifluoroethylated triazoles and trifluoroethylphosphonates.