Syntheses Of Trifluoroethylated Unsymmetrical 1,3-diynes By Using HCFC-123

Introducing a fluorine atom or a fluorine-containing group into a molecule can effectively enhance lipid solubility,metabolic stability,anti-oxidation stability,biological penetration,and rigidity of the origin molecule.Organic fluorinated molecules are widely used as pesticides,pharmaceuticals,materials,and substances in other important areas.In recent years,aromatic compounds containing 2,2,2-trifluoroethyl group are gradually found to have high biological activity.However,synthetic methodologies of 2,2,2-trifluoroethyl-containing compounds are lack and have attracted more attention.On the other hand,unsymmetrical 1,3-diyne compounds have become a class of important organic intermediates,and they can also be structural units of natural products with biological activities.Unsymmetrical 1,3-diynes have also been widely used in the synthesis of various types of heterocyclic compounds which are potential applicable in medicine,optical materials,liquid crystal materials.This dissertation mainly describes the copper-promoted syntheses of 2,2,2-trifluoroethylated unsymmetrical 1,3-diynes.The reactions use terminal diynes as starting materials and 1,1-dichloro-2,2,2-trifluoroethane(HCFC-123)as trifluoroethyl source.HCFC-123 is cheap and readily available.The reactions tolerate a wide range of functional groups and give products in medium to good yields(40-75%).Further transformation of the product was explored to afford trifluoroethylated isoxazole and triazole in good yields.