The Reaction Of Vinylogous Imine Intermediates With Sulfur Ylides And Dicarbonyls

Dearomatization reactions are important transformations of aromaticcompounds owing to that they directly lead to a variety of ring systems. Additionally,these aromatic cores are the key intermediates of many natural products andpharmaceuticals. Thus, the strategy of dearomatization has been widely used in thesynthesis of agents, pesticide and materials. Though a variety of synthetic methodshave been developed about dearomatization, considering the importance of indoledearomatization, a concise and efficient synthetic method for indoledearomatization still remains great significance.Vinylogous imine intermediate based on indole skeleton has been confirmed tobe a good electrophilic acceptor and useful intermediate in the synthesis ortransformation of indole. It can be generated using in either basic or acidic reactionconditions, which upon with the nucleophilic agents to afford the correspondingsubstituted indoles. A series of reactions involved this intermediate have beenreported, and satisfactory substituted indoles were obtained conveniently.This thesis focused on the dearomatization of indole derivarites, and describesour recent research on the transformation of vinylogous imine intermediate, and thisthesis contains the following three parts:In chapter1, some of the recent developments on the dearomatization of indolederivarites and the synthesis of spiro-cyclopropane compounds are summarized.In chapter2, a concise and efficient synthesis of spiro-cyclopropane compoundsvia the dearomatization of indole derivarites was developed. The main advantages ofthis route are excellent diastereoselectivities, good yields, mild conditions and theraw material is cheap and easy to get. A preliminary study on the enantioselectiveversion of this reaction was also examed, and promising results were obtained.In chapter3, an efficient addition reaction of dicarbonyl compounds tovinylogous imine intermediate generated in situ from sulfonylindoles was realized.This strategy provided a facile access to the relevant C3-sec-alkyl substitutedindoles in moderate to high yields with a wide range of substrates. At the same time,the experiment of gram scale was also achieved successful，which can also improvethe practical application of this reaction.