Study On The Synthesis Of Phosphonate Derivatives Catalyzed By Lanthanide Amides

The lanthanide amides catalyzed reaction for the synthesis ofα-oxindole-α-hydroxyphosphonate as well as chiral synthesis of γ-oxophosphonate wasstudied in this thesis. The main contents of the thesis are as in the following.1. Lanthanide silylamides [（Me₃Si）₂N]₃Ln（μ-Cl）Li（THF）₃were found to be highlyefficient catalysts for the phospho-aldol reaction of various isatins and dialkylphosphites. The reactions produced α-oxindole-α-hydroxyphosphonates in good toexcellent yields in the presence of1.0mol%[（Me₃Si）₂N]₃La（μ-Cl）Li（THF）₃at roomtemperature within5min. The tetracoordinate lanthanide amides[（Me₃Si）₂N]₃Ln（μ-Cl）Li（THF）₃exhibited the catalytic activity superior to that oftricoordinate lanthanide amides Ln[N（SiMe3）2]3. The influence of lanthanide metal andreaction conditions on the catalytic activity was investigated and the mechanism for theprocess of high efficiency was proposed.2. The enantioselective phospha-Michael addition of diethyl phosphite toα,β-unsaturated ketones using catalytic amount of chiral lanthanide amides, in situformed by the reaction of [（Me₃Si）₂N]₃Ln（μ-Cl）Li（THF）₃and chiral ligands includingdiols and Schiff bases, was explored. Salens were found to be effective chiral ligands inthe asymmetric synthesis of γ-oxophosphonates and moderate to good yields （up to81%）and good enantioselectivities （up to90%ee） were achieved.