Alkynylation And Trifluoromethylation Of C(sp~2)-F Bonds

The C-F bond is the strongest single bond in organic chemistry due to its partial ionic character. Activation of C-F bond is a new challenge for chemists. Recently, there is growing concern about functionalization of C-F bond (C(sp2)-F bond in particularly) among chemists. The major content of this dissertation includes the study on ethinylation of aryl fluorides and alkenyl fluorides, trifluoromethylation of alkenyl fluoride. A novel, one-pot, three-component approach for the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles was also studied.1. We have successfully developed the Sonogashira-type reaction of aryl fluorides and terminal acetylenes. The reaction proceeded smoothly in the presence of sodium, calcium hydroxide and sodium methoxide with the assistance of Grignard reagent.2. We developed a mild and convenient method for the stereoselective synthesis of conjugated β-fluoroenynes by the reaction of gem-difluoroalkenes and terminal alkynes with the assistance of n-butyllithium and K3PO4.3. We developed the trifluoromethylation of alkenyl fluorines. gem-Difluoroalkenes can be trifluoromethylated under the TMSCF3/TBAF/THF system. Nitrogen heterocyclic substituted alkenyl fluorides can be also trifluoromethylated under PdCl2(PCy3)2/TMSCF3/TBAF/THF system. On the other hand, gew-Difluoroalkenes can be pentafluoroethylated under the TMSCF2CF3/TBAF/THF system.4. We developed synthesis of 1,4,5-trisubstituted 1,2,3-triazoles by the reaction of primary alcohols, sodium azide and active methylene ketones with the assistance of N-(p-toluenesulfonyl) imidazole, tetrabutylammonium iodide, and trimethylamine in DMF/DMSO.