The Synthesis And Application Of The Dendritic Molecule Based On The Ferrocenyl Framework Phosphine Ligands

The design of new chiral ligands is key in the development of transition metal catalyzed asymmetric reaction. Many effective chiral phosphines based on phenyl, binaphthyl, ferrocene and other backbones have been developed during the last several decades. Subtle changes of chiral ligands in geometric, steric,and electronic properties can be by use of introducing of dendrimers. Chiral ligand does not have an effect on all of the catalytic reaction, So we need to continue to explore the novel structure and excellent performance of chiral ligands. We designed and synthesized Ferrocenyl chiral phosphine ligands through the incorporation of dendrimers.1. The synthesis of monophosphine ligandswe use cheap and readily available Ferrocenecarboxaldehyde as raw material,which react with (S)-methoxymethylpyrrolidine for introducing chiral ortho-directing group,and then introduce CIPPh2by ortho-metallation. the intermediate product coupled with different generations of dendrimers derivated three novel chiral compounds after removing of ortho-directing group. In the process of reaction chiral phosphine oxides were obtained. Chiral ligands were characterized by NMR,HRMS,IR.2. The synthesis of diphosphine ligandswe use1,1’-ferrocenedicarboxaldehyde as raw material, then introduce CIPPh2by di-ortho-metallation of a1,1’-disubstituted ferrocene bearing chiral ortho-directing. After removing of ortho-directing group,we intend to coupled with different generations of dendrimers with it, which is under exploration.3. The application of monophosphine ligands in the asymmetric Suzuki-Miyaura reactionThe target ligands was hoped to be used in the asymmetric Suzuki-Miyaura coupling reaction, we proceeded to perform several coupling reactions with the trivalent chiral phosphine ligands, however, we found dehalogenation of aryl halides instead of target coupling product. Trace of target coupling product wouled be detected if the reaction performed with the Pentavalent chiral phosphine ligands,but the dehalogenation of aryl halides also very serious.