A Study On Heterocyclic Ketene Aminals And The Synthesis And Structural Characteristic Of Its Derivatives

Heterocyclic ketene aminals is used as versatile synthons in the synthesis of heterocyclic compounds. Its preparations, the structure feature, the reactive properties and the applications in organic synthesis have already been researched thoroughly. The main object of this thesis is to investigate the reaction of heteroclic ketene aminals .The work of this paper is summarized as follow.This thesis includes two parts of research work. Part A deals with a systematical investigation on the nucleophilic addition reaction of heterocyclic ketene aminals with several electron deficient reagents. Part B described a novel approach to the synthesis of heterocyclic enamines starting from cyclic ketones.Part A1. Describe carefully synthesis of Heterocyclic Ketene Aminals. 2.The electrophilic additive reaction of Heterocyclic Ketene Aminals:Heterocyclic Ketene Aminals iS a especial mono—aza—ene component,the addive reaction of Heterocyclic Ketene Aminals with a system of a,B一unsaturated compounds or the ester—and cyano—compounds is passed the path of the aza—ene reaction. 3.Heterocyclic Ketene Aminals can occur the substitution reaction of twonucleophilic reageant,such as regiospecific alklation reation,regioselectic acylation reaction.the sugarlation reaction,the halogennating reation,the nitrating reaction and the cvclic addive reaction with the 1,3-dipole reagent.The 1:l nucleophilic adducts were sole products of the reaction between heterocyclic ketene aminals and nitrile vlides.The reaction can occur at the a—C atom of heterocyclic ketene aminals.which afford the C—substituted products,and can also Occur at the N—atom,which yield the N—substituted products.Part B: The reaction of heterocyclic ketene aminals with ethyl bromo-acetate, under netual condition, gives four new heteocyclic products, [3 3 0] and [4 3 0] with excellent yields.Their structures were carefully proved by NMR, IR and elemental analyses etc.