Research On Addition Reaction Of 2-Substituted Pyridine With Nitrile And Their Zinc Complexes

Recently,the rise of bio-degradable materials indicates that chemical research has entered the "green" era.As a key to these synthetic materials,the catalysts also develop toward "green" gradually.The zinc,magnesium and aluminum metal complexes,as one better performance and less toxic aliphatic polyester catalysts are widely used in organometallic chemistry.N,O-coordinated containing trimethylsilyl magnesium,aluminum and zinc complexes are well applied to caprolactone and lactide ring-opening polymerization,which can act as catalyst or be involved in the the reaction as cocatalyst.On the other hand,the metal and the ligand structure of such catalysts have a obvious influence on its selective and catalytic performance,so it is very significant to synthesize catalysts with different performance characteristics by changing ligand structure and metal center.Our research group has focused on the synthesis of pyridyl-N,O and-N,N bidentate metal complexes and its catalytic properties in aliphatic polyester for a long time.This essay is divided into three parts:Chapter 1.The introduction generalizes the development of biodegrade-able aliphatic polyester material(PLA and PCL),and the application of N,O-coordinated containing trimethylsilyl metal complexes catalytic system into ring-opening polymerization.Chapter 2.2-Methyl-pyridine and 2-ethyl-pyridine were lithiated respectively,and then occured insert-reaction with several non a-H nitriles,acidic hydrolysis,neutralization,distillation.We synthesized some zinc complexes via the obtained ligands reaction with diethyl zinc.In addition,we studied the catalytic performance of these complexes towards the ε-CL ring-opening polymerization.These complexes were characterized by NMR,elemental analysis and single crystal X-ray diffraction.Chapter 3.(1)2-Benzyl-pyridine was lithiated,then occured insert-reaction with several non a-H nitriles,acidic hydrolysis,neutralization,and purification to afford different compounds from the traditional way.(2)2-Benzyl-pyridyl-lithium compounds,which introduced the trimethylsilyl group,occured insert-reaction with above-described nitriles,hydrolysis and purification to get the expected compounds.We studied the insert-reaction of 2-benzyl-pyridine alkyl lithium compounds with non α-H nitriles by compareing(1)and(2).The above-compounds were characterized by NMR and single crystal X-ray diffraction.