Organocatalytic Asymmetric Decarboxylative Reactions Of β-keto Acids With Cyclic α-ketiminophosphonates To Access Quarternary α-aminophosphonates

Due to its particular biological activity,optically active α-aminophosphoric acid,an important amino acid analogue,has a wide range of applications in biochemistry and pharmaceutical science.Especially,the quaternary α-aminophosphoric acid is widely concerned by chemists because of its structural specificity.Therefore,many synthetic methods have been developed.However,most of them are synthesis of acyclic α-aminophosphoric acids.The cyclic quaternary α-aminophosphoric acids are relatively rare.In this dissertation,the asymmetric decarboxylative Mannich reaction of β-keto acids with cyclic α-ketoenmidophosphonates was catalyzed by a novel saccharidederived bifunctional amino-thiourea,and a series of cyclic quaternary carbon-centered α-aminophosphonic acids were constructed,including five-membered and six-membered ring structures.After the optimizations of reaction conditions,the products were obtained in 78-93% yield with 90->99% enantioselectivity,and the absolute configuration of 3i was determined by X-ray diffractometer.