Visible-Light-Induced[3+2]Annulation And Synthesis,Application Of Novel Chiral-at-Metal Ligands

Visible-light photocatalysis has been developed rapidly in the field of organic synthesis in the past decade.It is an important research area to use visible-light photocatalysis to construct molecules that are difficult to synthesize through conventional thermal process.In the first part of this thesis,we report a visible-light-induced[3+2]annulation of arylcyclopropylamines with 1,2-diarylethanediones.A range of potentially bioactive a-amino furan derivatives have been synthesized.Significnat progress have been made in asymmetric catalysis with the use of various chiral metal complexes based on central-,axial-and planar-chiral ligands.The development of new chiral ligands is the key to transition-metal asymmetric catalysis.In the second part of this thesis,one class of novel chiral-at-metal ligands based on chiral-at-metal complexes and various bridge ligands have been developed,which exhibit excellent performance in asymmetric Michael addition of a-ketone esters with nitroalkenes.The first chapter gives a brief summary on the progress of visible-light photocatalysis in organic synthesis and transition-metal catalyst in asymmetric catalysis.The second chapter is about visible-light-induced[3+2]annulation of cyclopropylamines with 1,2-diketone derivatives.It is the first report of[3+2]cycloaddition between cyclopropylamines and carbon-oxygen double bonds.A range of a-amino furan derivatives have been synthesized by one step.This reaction has the advantages of simplified operation,good to excellent yield and high atomic economy.This strategy provides an efficient and convenient route to synthesis of the potential bioactive molecule α-amino furan derivatives.The third chapter is about the synthesis and application of novel chiral-at-metal ligands.We have designed one class of chiral-at-metal ligands based on octahedralcentered chirality,and developed their efficient synthetic route.These new ligands have been successfully applied to the asymmetric Michael addition of α-ketone esters and nitroalkenes,providing with good to excellent stereoselectivity and yields.The fourth chapter is the summary and prospect of this thesis.