Study On The Heck Coupling Reaction And Suzuki Coupling Reaction In Green Media

The green organic synthetic chemistry, that is developing environmentally friendly methods in organic synthesis, is the research hot spot and the frontier in the chemistry field at present. It is an important subject of green chemistry to look for environment-friendly reaction medium instead of traditional organic solvent. Liquid low-molecular-weight polyethylene glycol (PEG) is of great concern by researchers as a new type of green organic reaction solvent. PEG has the advantages of non-toxic, biodegradable, non-volatile, non-flammable, good thermal stability, as well as easy recovery and recycling. In addition, PEG can dissolve a large number of organic compounds and organic metal complexes. Therefore, PEG as a substitute for organic solvents and homogeneous catalyst carrier has been successfully applied to many organic reactions.This thesis is divided into three chapters.Chapter 1: The Research Progress of Carbon-Carbon Bond Cross-Coupling Reactions in Green Medium.This chapter reviews the research progress of carbon-carbon key cross-coupling reaction in recent years.Chapter 2: Study on Reusable, Ligand-Free Heck Reaction in PEG-400 Assisted by Focused Microwave Irradiation.A rapid and efficient Heck coupling reaction of aryl iodides with terminal olefins is conducted in PEG-400 at 120 oC in the presence of potassium carbonate and palladium nanoparticles in situ formed from palladium chloride under focused microwave irradiation. The high to excellent yields are achieved. The reaction medium and catalyst can be easily recycled at least five times without significant loss in reactivity.Chapter 3: Study on Ligand-Free Suzuki–Miyaura Cross-Coupling Reaction in PEG-400 and PEG-400/H₂O.This chapter includes two parts. Part one: An ultrafast and highly efficient ligand-free Suzuki–Miyaura cross-coupling reaction between aryl bromides/iodides and aryl boronic acids using palladium chloride as catalyst in PEG-400/H₂O in air at room temperature has been developed. Part two: A rapid and efficient Suzuki–Miyaura cross-coupling reaction of aryl iodides with aryl boronic acids is conducted in PEG-400 in the presence of potassium carbonate under microwave irradiation.