Studies Of The Organic Base Catalyzed Reactions Based On Electron-Deficient Alkyne

The dissertation is mainly focused on the application of organic base as catalyst to catalyzed reactions based on the electronic-deficient alkynes. Except that, direct iodination of monosubstituted acetylernes was also studied and the iodoacetylenes were used to synthesis of 1,3-butadiynes in the presence of copper powder.This dissertation includes four chapters.Chapter one:application of organic base as catalyst in organic synthesis.In this chapter, detailed review was systematically described about the application of organic base as catalyst in organic synthesis.Chapter two:cycloaddition of alkynyl ketones with N-Tosylimines catalyzed by Bu3P and DMAP.Cycloadditon of alkynyl ketones with N-Tosylimines catalyzed by organic base to synthesize azetidines and pyrrolidines were systematically described. In the reaction of alkynyl ketones with N-Tosylimines catalyzed by Bu3P in toluene, highly functionalized pyrrolidines were formed in good to excellent yields. When DMAP was in place of Bu3P as catalyst to facilitate the cycloaddition, a completely substituted azetidines were produced in moderate to good yields in CH2CI2. Both of cyclization reactions proceeded smoothly with complete stereoslectivity.Chapter three:the study of organic base catalyzed reactions based on the terminal alkynoates.The reactions of terminal alkynoates with 1-(o-hydroxyaryl)-1,3-diketones, 2-hydroacetophenone, aromatic aldehydes catalyzed by organic base were detailed researched, respectively. (1) PPh3-catalyzed a-addition of 1-(o-hydroxyaryl)-1,3-diketones to terminal alkynoates involving carbon-carbon bond cleavage to give multifunctional vinylesters is described; (2) PPh3-mediated double a-addition reaction of ortho-acylphenols to ethyl propiolates to generate functionalized 1,4-pentadienes; (3) the reaction of 2-hydroacetophenone and terminal alkynoate successively catalyzed by DABCO and mediated by KOBut to synthesis of chromanone derivative. (4) PPh3-catalyzed multicomponent reaction of terminal alkynoates with aromatic aldehydes to afford multifunctional vinylesters.Chapter four:iodination of monosubstituted acetylenes and homocoupling of 1-iodoalkynes. Reaction of aryl acetylenes with molecular iodine in the presence of DMAP gave the iodoacetylenes, meanwhile, iodination of aryl acetylenic ketones using K2CO3 as base was also described. Furthermore, homocoupling of iodoacetylenes in the presence of copper powder gave the symmetrical 1,3-butadiynes was investigated.With the development of study of organic base catalyzed reaction based on the electronic-deficient alkyne, we have extended the scope of application of organic base as catalyst in organic synthesis. Moreover, we have provided some straightforward methods to synthesis of potential organic intermediates.