Synthesis And Application Of The Chiral Amino Alcohol Ligands Containing Camphor Skeleton

Two chiral amino alcohol ligands containing camphor alkyl skeleton were synthesized from easily available natural camphor, respectively. The systematic studies on these chiral ligands were carried out for the application in the catalytic asymmetric addition of diethylzinc to aldehydes.一.Synthesis of the chiral ligand5Chiral ligand5was prepared from easily available natural camphor by oxidation, oximation, reduction, and then treatment with1,4-Dibromobutane. The chiral ligand5was characterized by1H NMR,13C NMR, IR and MS.二. Synthesis of the chiral ligand6Chiral ligand6was prepared from easily available natural camphor by oxidation, selective reduction, imidization, reduction by NaBH4and Pd/C, and then treatment with1,4-Dibromobutane. The chiral ligand6was characterized by1H NMR,13C NMR, IR and MS. Asymmetric ethylation of aldehydes catayzed by chiral ligand5and6was investiged. The experimental results show that, as predicted, the ligands5and6, respectively, gave (S),(R)-configuration of secondary alcohols, in100%chemical yield and98%ee value.The Methyl nadic anhydride (MNA) is an important industrial curing agent, and is extensively applied in electronics, electrical and aerospace. MNA of industrial application is the exo-MNA mainly, but MNA of synthesis is the endo-MNA mainly. In order to solve this problem, we have studied the Methyl nadic anhydride synthesis and isomerization and found the best conditions of the synthesis and isomerization.