Synthesis,Characterization And Application Of Ferrocenyl Phosphine Ligands With Planar Chirality And Central Chirality

Ferrocene has unique spatial structure can build planar chirality,ferrocenes with planar chirality have been used as a skeleton of chiral ferrocenyl phosphine ligands.Among them,the most famous is the ferrocenyl phosphine ligand Josiphos with planar chirality and central chirality,it has been used in large-scale industrial production,the important intermediate in the synthesis process of pesticide（S）-metolachlor is obtained via Ir-Xyliphos catalyzed the asymmetric hydrogenation reaction,the annual output of this pesticide is at least 10000 tons.This thesis synthesized new ferrocenyl phosphine ligands with planar chirality and central chirality,two synthetic methods have been developed and they both first need to construct planar chirality,then using planar chirality induction to generate central chirality:one,ferrocenehydrazones is coupling with 2-bromobenzeneboronic acid to produce 2-bromophenylmethyl ferrocene,and using palladium-catalyzed intramolecular enantioselective C-H cyclization to synthesize planar chiral ferrocene indene;two,synthesis of planar chiral ferrocenyl indanone via palladium-catalyzed intramolecular enantioselective C-H cyclization of o-bromobenzoylferrocene,then synthesis of planar chiral ferrocene indene through reduction.Ferrocenyl phosphine ligands with two chiralities were synthesized successfully by lithation of planar chiral ferrocene indene with n-butyllithium and quenching with R₂PCl.Through continuous optimization of reaction conditions and diastereoselectivity,chiral ferrocenyl dicyclohexylphosphine ligand 2d has the yield of 76%and de value of 97.8%.We studied two synthetic methods are simple and easy to operate,use cheap and readily available materials,the reaction conditions are mild and have good universality.It’s worth mentioning that synthesis of the target compounds only need catalytic amount of chiral ligands.The catalytic performance of chiral ferrocenyl dicyclohexylphosphine ligand 2d in asymmetric MBH reaction was investigated,but the attempted experiments didn’t obtain the expected product.The raw materials of the asymmetric[3+2]cycloaddition reaction were synthesized,next the ligand 2d will be tested in this reaction.These compounds were characterized by nuclear magnetic resonance(¹H NMR,¹³C NMR and ³¹P NMR),melting point,high resolution mass spectrometry（MS）,high performance liquid chromatography and single crystal diffraction.