One-pot Reactions Based On Coupling Of Terminal Acetylenes And Acyl Halides

Palladium-catalyzed coupling reaction of terminal alkynes and acyl halides has attracted much attention,as the ynone products are important intermediates for the synthesis of a variety of organic compounds and have wide applications.Ynones can be used for the preparations of ?-halogenated-?,?-unsaturated ketone and 1,3-dicarbonyl compounds.However,stepwise reactions are generally required in the reported methods.Ynones should be prepared and isolated first,and many subsequent transformations need to be realized at high temperature,with long reaction time,or need precious metal catalysts and ligands.These are not in line with the concept of green chemistry.In this thesis,starting from terminal alkynes and acyl halides,one-pot coupling reactions without separation of ynone intermediates were realized.The following two aspects are included:(1)Study on the green synthesis of ?-halogenated-?,?-unsaturated ketones.Palladium/copper catalyzed coupling reaction of terminal alkynes and acyl halides was done at room temperature for 10 min,and then trifluoromesylate was added.After 4 h,a series of ?-halogenated-?,?-unsaturated ketones were obtained in high yields through column separation.Part of the synthesis of a single stereoselective product can be realized through the regulation effects of solvent and substituents.The reaction does not need additional halogen source,so the atom economy is good.The eaction is green,simple,and efficient,and functionalization of the halide products could be easily done for synthesis of important chemicals.(2)Study on green synthesis of 1,3-dicarbonyl compounds.Palladium/copper catalyzed coupling reaction between terminal alkynes and acyl halides was carried out at room temperature for 10 min,and then the solvent was removed under vacant.Trifluoromesylate and methanol were added to the reaction mixture without separation.After 2 h,a series of 1,3-dicarbonyl compounds were obtained in high yields.The efficient synthesis of 1,3-diketones was realized without separation of ynone intermediates,and no noble metal catalyst is required in the current transformation.