Rapid Access To4-substituted-2-pyrones And2(5H)-furanones Via A Palladium-catalyzed C-OH Bond Activation And Copper-catalyzed Homo-coupling Reactions Of Terminal Alkynes

Transition metal-catalyzed crossing-coupling reaction is one of most effectiveprocedures for the construction of C-C bonds. It plays an important role in modernorganic synthesis. In this thesis, palladium-catalyzed C-OH bond activation Suzukicross-coupling reactions and homo-coupling of terminal alkynes catalyzed by copperwere studied in detail.In part one, palladium-catalyze C-OH bond activation Suzuki cross-couplingreaction of6-methyl-4-hydroxy-2-pyrone，6-methyl-3-Bromo-4-hydroxy-2-pyrone，and4-hydroxy-2（5H）-furanone with various arylboronic acids were studied in detail.The results indicated that p-toluene sulfonyl chloride is an important and universalactivated reagent. Under the optimized conditions-10mol%PdCl₂（PPh₃）₂,110mol%p-toluene sulfonyl chloride,300mol%K₂CO₃in THF/H₂O, the Suzuki reactions6-methyl-4-hydroxy-2-pyrone，6-methyl-3-Bromo-4-hydroxy-2-pyrone and4-hydroxy-2（5H）-furanone with various arylboronic acids worked well and effectively,and gave the corresponding products in good to excellent yields.In part two, copper-catalyzed homo-coupling reactions of terminal alkynes werestudied in detail. When CuI was used as the catalyst, CAN as the oxidant, K₂CO₃asbase, The homo-coupling reactions of terminal alkynes proceeded very well in DMFat70℃, gave the corresponding1,3-diynes in excellent yields。...