Synthesis And Application Of A Novel Ligand Containing 2-pyridone Skeleton

Innovations in synthetic chemistry are enabling drug developers to more rapidly and costeffectively synthesize complex molecular structures that are biologically active.The carbonhydrogen bond activation reaction catalyzed by palladium can directly convert the carbonhydrogen bonds in a large number of organic molecules into functional groups,and its highefficiency reaction characteristics have made it widely used in the field of medicine.To solve the activation problem of inert carbon-hydrogen bonds,directing group strategies and ligand strategies are commonly used.Ligands are the key to solving the activation of carbonhydrogen bonds in unguided arenes,and the 2-pyridone skeleton has been proved to have a strong acceleration effect on the step of carbon-hydrogen bond cleavage.The purpose of this thesis is to develop a new class of ligands containing 2-pyridone skeleton and to apply them in the palladium-catalyzed activation of carbon-hydrogen bonds of unguided arenes.The research is divided into three parts:1.Three series of novel ligands were designed and synthesized:2-pyridone-oxazoline,2pyridone-imidazoline and 2-pyridone PCN ligands.The first two series of ligands each have three subtypes according to structural differences.Synthetic applications of pincer metal catalysts were carried out for PCN-type ligands.The ligands and pincer metal complexes were characterized by a series of techniques such as NMR and single crystal XRD.2.The application of novel ligands of 2-pyridone-oxazoline and 2-pyridone-imidazoline to palladium-catalyzed non-directed alkenylation of arenes.The reaction uses Pd(OAc)2(10 mol%),Cu(OAc)2(1 eq.),and explores the influence of ligand differences on the reaction under the condition of using excess aromatic hydrocarbons.Under the optimal ligand control,rich Electron and electron-deficient arene substrates were reacted with various alkenes in good yields.The equivalent reaction conditions of arene alkenylation were tried,and the template reaction of benzene(1 eq.)with butyl acrylate had 50%yield under optimized conditions.3.Guided by the results of the alkenylation reaction,the ligands with better effects were applied to the palladium-catalyzed synthesis of polycyclic aromatic hydrocarbons from unguided arenes and alkynes.The reaction conditions were screened and optimized.At 80℃,using Pd(OAc)2(10 mol%)and AgOAc(2 eq.),various aromatics were cyclized with two molecules of diarylacetylene to obtain highly substituted naphthalene.The reaction process undergoes two carbon-hydrogen bond activation steps,and part of the substrates obtains a single carbon-hydrogen bond-activated addition-type olefin product during the reaction.