Synthesis And Norbornene Polymerization Behavior Of CNN And PCN Pincer Palladium (?) Complexes

The pincer palladium(?)complexes were an important class of pincers metal complexes,which have good catalytic activity in olefin polymerization.In particular,the application of pincer palladium compounds containing oxazoline coordination and pincer palladium compounds containing soft atom coordination in the polymerization of norbornene has attracted wide attention.This thesis is based on the previous research of our research group,using 6-bromopyridine-2-carbaldehyde as the starting material,8 kinds of chiral and achiral CNN pincer palladium compounds were synthesized by the C-H bond activation method.3-hydroxybenzaldehyde was used as the starting material,via one-pot phosphorylation/palladation reaction afford 6 kinds of achiral PCN pincer palladium complexes;using 3-hydroxybenzoic acid as the starting material,via one-pot phosphorylation/palladation reaction afford 3 kinds of chiral PCN pincer palladium complexes.The catalytic activity of CNN and PCN pincer palladium compounds in the polymerization of norbornene was investigated by using different cocatalysts EtAICl2,Et2AICl or MAO.Among them,when Et2AICl is used as the cocatalyst,the CNN pincer palladium compound exhibits better catalytic activity;when MAO is used as the cocatalyst,the PCN pincer palladium compound exhibits better catalytic activity.