Synthesis Of 2-(2-pyridyl)-ketone Ligands And Their Zinc, Aluminum And Magnesium Complexes

Organozinc,-aluminum and-magnesium compounds have attracted considerable attention due to their widespread use in organic synthesis and in polymerization chemistry, e.g. organoaluminum compounds as catalysts or co-catalysts for olefin polymerization and organozinc,-aluminum and-magnesium compounds as initiators for the ring-opening polymerization (ROP) of cyclic esters. The foundation of the applications is a fundamental understanding of the chemistry of these compounds. Hence it is essential to explore the structural features, stability and reactivities of the complexes.In this dissertation, we focus on designing and synthesizing a series of organmetallic compounds with 2-methyl pyridine, then, discuss the application of these organometallic Zn, Al and Mg complexes in the polymerization of s-CL. Firstly, a novel series of 2-(2-pyridyl)ketone ligands were synthesized by the reaction of 2-methylpyridine with nBuLi, nitriles, the hydrolysis in acid solution. Those ligands react with ZnEt2, AlMe3 and MgBu2 to yield relative metallic complexes. Secondly, two kinds of bis(substituted-indenyl)methanes ligands were synthesized by the reaction of substituted phenyl with 3-chloropropanoyl chloride, concentrated sulphuric acid, LiAlH4 and KHSO4. This ligand was reacted with Zr(NMe2)4 to yield relative metallic complex. Thirdly, we study the application of those Mg, Al and Zn complexes in ring-opening polymerization of ε-caprolactone. Finally, some ligands and organometallic complexes were characterized by 1H NMR and 13C NMR. The main content include four parts as follows:Chapter 1. Herein the function of the PCL, ε-caprolactone ring-opening polymerization mechanism and the development of some zinc, aluminum and magnesium catalysts were reviewed.Chapter 2. A novel series of 2-(2-pyridyl)-ketone ligands were synthesized by the reaction of 2-methylpyridine with nBuLi, nitriles, the hydrolysis in acid solution. Those ligands react with ZnEt2, AlMe3 and MgBu2 to yield relative metallic complexes. And some parts of the compounds were characterized by 1NMR and 13C NMR.Chapter 3. Two kinds of bis(substituted-indenyl)methanes ligands were synthesized by the reaction of substituted phenyl with 3-chloropropanoyl chloride, concentrated sulphuric acid, LiAlH4 and KHSO4. This ligand were reacted with Zr(NMe2)4 to yield relative metallic complex. And some of the compounds were characterized by 1H NMR and 13C NMR.Chapter 4. We study the application of those Zn, Al and Mg complexes in ring-opening polymerization of s-caprolactone and we discuss that polymers with different yields can be obtained under various conditions.