Studies On Palladium-Catalyzed Carbon-Carbon Bond Formation Reaction In PEG And Ionic Liquids

This dissertation consists of three parts:Part one: We investigated palladium-catalyzed carbonylative Sonogashiracoupling reaction from aryl iodides and various terminal acetylenes in a mixed solventof PEG-2000and water under atmospheric carbon monoxide. It was found that thereaction proceeded smoothly at room temperature to afford a variety of alkynylketones in good yields and the PEG-2000-PdCl₂（PPh₃）₂-H₂O catalytic system can berecycled many times without any decrease in reaction efficiency. Meanwhile thismethod was applied to the synthesis of2-substituted flavones in moderate yields, sothe protocol will serve as a practical way to synthesize alkynyl ketones and2-substituted flavones.Part two: We investigated base-free palladium-catalyzed homocoupling ofarylboronic acids in PEG-2000under air, the reaction gave a variety of symmetricalbiaryls in high yields. The PEG-2000could immobilize palladium catalyst andphosphine ligand, and the Pd（OAc）₂-PEG-2000-PPh₃catalytic system can be recycledfive times with high efficiency for the homocoupling of arylboronic acids, we havedeveloped a simple and green process for the preparation of symmetrical biaryls.Part three: A hydrophobic ionic liquid, namely,1-butyl-3-methylimidazoliumhexafluorophosphate （[bmim][PF₆]） was prepared according to the literature method.We studied water-promoted addition reaction of arylboronic acids with aldehydes byusing Pd（OAc）₂as the catalyst and （1-Nap）₃P as the ligand in ionic liquids. Thereaction afforded carbinol derivatives in good to excellent yields at65oC. ThePd（OAc）₂-[bmim][PF₆]-（1-Nap）₃P catalytic system can be recycled many timeswithout no significant loss of the catalytic activity, the methodology has provided agreen and practical procedure for the synthesis of carbinol derivatives.