Studies On Asymmetric Mannich Reaction Of Bestmann-Ohira Reagent Catalyzed By Quaternary Ammonium

In this dissertation, a series of quaternary ammonium salt phase transfer catalysts derived from the cinchona alkaloids were desigened, synthesized and applied to the Mannich reaction between a-amino sulfone with Bestmann-Ohira reagent (dimethyl (1-diazo-2-oxopropyl) phosphonate,1) to prepare β-amino phosphonate compounds. After initial catalyst screening and reaction condition optimization, good yield (87%yield) and moderate enantioselectivity (73%ee) were achieved when the reaction was catalysed by the quaternary ammonium phase transfer catalyst7g derived from quinidine. We hope to improve the enantioselectivity of β-amino phosphonic acid and its derivatives by further optimizing the catalytic reaction condition.