Synthesis And Application Of Polyethylene Glycol Supported Chiral Ligand Of Ferrocenyl-diphenyl-amino Alcohols

Polyethylene glycol supported catalysts have good solubility in many solvents and when the reaction is end, it is very easy to be separation, recoveryed and be circulated. In addition, the ferrocenyl aziridination is a very good chiral skeleton, so the design and synthesis of polyethylene glycol supported ferrocenyl-diphenyl-amino alcohol chiral ligands is used to catalyze asymmetric nucleophilic addition of aromatic aldehydes with diethylzinc.1. Synthesis of polyethylene glycol supported chiral ligand of ferrocenyl-diphenyl-amino alcoholsChiral ligands7were prepared through a six-step synthesis from essily available Z-serine1. In the synthetic process of compounds7,I synthesized new compounds of5,5’and6. All novel compounds were characterized by4HNMR,1CNMR, HRMS and IR. The specific rotation of compounds5,5’,6and7were recorded.2. The ligands7is used to catalyze the asymmetry nucleophilic addition reactions of aromatic aldehydes with diethylzinc. In this reaction, firstly, I examined the asymmetric nucleophilic addition reaction of benzaldehyde with diethylzinct with ligand7, and selected the amount of screening ligand and the reaction temperature to determine the optimal reaction conditions. Under optimum reaction conditions, the expansion of the aromatic aldehyde substrate, and then study the electronic effects and spatial effects in the reaction.The best result was the yield was88%and ee was up to92%in the asymmetric nucleophilic addition reaction of benzaldehyde with diethyl in the amount of ligand7in3mol%and25℃.