Preparation Of Hydrogen-bonded Chiral Ruthenium Catalyst And Study Of Its Catalytic Properties

The discharge of metal compounds in the homogeneous catalyst into the environment poses a serious hazard to the environment,which greatly limits the continuous use of the catalyst.Therefore,the homogeneous catalyst supported on the carrier material to achieve the recycling of the catalyst has become another important area of green chemistry research.The one-pot catalytic multi-step tandem reaction is an important aspect of green chemistry research,which simplifies the operation steps and improves the atomic utilization rate,thus becoming an important research hotspot of modern chemical workers.This paper is divided into the following two parts:(1)In the first part,firstly,we synthesize an inorganic skeleton of short straight pore silicon nanospheres.Then,Bis[(pentamethylcyclopentadienyl)dichloro-rhodium]((Cp*RhCl2)2)was prepared as an ion pair catalyst(Cp*RhTsDPEN)+(BF4)-,coupled with(S,S)-TsDPEN chiral ligands.Then,the ion-pair chiral rhodium homogeneous catalyst was supported on the carrier material by hydrogen bonding.Finally,we demonstrate that hydrogen-supported monofunctional catalysts have been successfully prepared by solid-state NMR 13 C spectra,29 Si spectra,TEM,SEM,XRD,BET,XPS,IR,TG and ICP.The catalyst was applied to the asymmetric hydrogen transfer reaction of aromatic ketone.The results showed that the catalyst had good catalytic activity,and we could see that the conversion rate and enantioselectivity were both up to 99%.Finally,we also recovered and reused the catalyst.The results show that the catalyst retains good catalytic activity and enantioselectivity after applying 10 times.(2)In the second part,firstly we prepared an organic salt with Triethylenediamine(DABCO)and chloropropyl silane.Then the mesoporous silica nanoparticles with DABCO basic functional groups were prepared by copolymerization.Then,the supported rhodium-supported bimetallic catalyst was supported on the carrier material.The results show that the hydrogen-supported supported rhodium-alkali bifunctional catalysts have been successfully prepared by solid-state NMR 13 C spectra,29 Si spectra,TEM,SEM,XRD,BET,XPS,IR,TG and ICP.The catalyst was applied to a one-pot synthesis of chiral ethylene oxide.The experimental results showed that the activity of the catalyst was good and the conversion and ee were 99%.Next,we also use the catalyst to the one-pot synthesis of chiral ?-amino alcohol.In this reaction,we choose isopropyl alcohol and water as a mixed solvent,choose sodium formate as a hydrogen source.It also achieved a good catalytic effect,and the conversion rate and ee values are both up to 99%.By tracking the reaction,we found that the aniline and 2-bromoacetophenone were substituted by the organic base DABCO catalyst and then subjected to asymmetric reduction under the catalyst of Cp*RhTsDPEN.Finally,we reused the catalyst.The results show that the catalyst still has a high catalytic activity after applying 7 times.