Electrophile-induced And Gold/Silver-catalyzed Tandem Reactions Of Alkyne

This thesis mainly aims at the studies on electrophile-induced and gold/silver-catalyzed tandem reactions of alkynes, which involves the following six chapters.In chapter Ⅰ, We divided two parts, which are (1) electrophile-induced tandem reactions of alkyne and (2) gold/silver-catalyzed tandem reactions of alkyne. For the first part, we expatiate from three aspects as follows:firstly, studies on synthesis of heterocycles via electrophile-induced tandem cyclization reactions of alkyne. Secondly, studies on electrophile-induced tandem ipso-cyclization.Thirdly, studies on electrophile-induced tandem cyclization reactions of propargyl alcohols. For the second part, we aims at the studies on gold/silver-catalyzed tandem reactions of alkyne.In chapter Ⅱ, we have given a brief summary on the recent studies about the synthesis of important heterocycles and carbocycles via electrophilic cyclization. Based on these research achievements, we developed a sequential cascade iodocyclization method for the synthesis of compouds, which are impossible to get through simple electrophilic cyclization. Noteworthily, cascade iodocyclization shows the undeniable benefits, including metal-free and mild conditions, as well as economies of time, labor, and waste generation. A variety of highly substituted 1,3-diiodinated naphthalene derivatives were formed via the above method. By the way, the dihalogenated moiety can be readily introduced into the naphthalenes in a position usually not easy to functionalize.In chapter Ⅲ, the recent studies on the electrophilic iodocyclization were briefly summarized. Next, we described in detail about the limitation of the ipso-iodocyclization currently. The previous electrophilic ipso-iodocyclization reports have focused on the following:(ⅰ) para-activated arylalkynes through the elimination of the leaving group to give the corresponding products; (ⅱ) para-unactivated arylalkynes through the external nucleophilic attack such as HOAc to produce substituted cyclohexadienes. While we developed an intramolecular electrophilic ipso-iodocyclization of para-unsubstituted aryl compounds combined with the Friedel-Crafts-type reaction to produce iodinated cyclization products in this report. This expanded the application scope of the ipso-iodocyclization.In chapter Ⅳ, firstly, we summarized rencent researches on gold-catalyzed rearrangement reactions of propargylic esters. Then, we designed a gold-catalyzed tandem [3,3]-propargyl ester rearrangement followed by a Michael addition under mild reaction conditions for the synthesis of (E)-1H-inden-l-ones. Noteworthily, the indane core, and specifically the indanone subunit, is a common skeleton in both natural products and synthetic drugs.In chapter Ⅴ, firstly, we summarized rencent researches on C-P bond construction and realized the superiority of this strategy which via the addition of P-centered radicals to unsaturated systems than the traditional methods. Then, we described in detail about the limitation of the C-P bond construction through the radical way currently. While we developed a silver-catalyzed cascade difunctionalization of N-(p-methoxyaryl)-propiolamides coupled with dearomatization. Noteworthily, organophosphorus compounds are a highly important class of compounds which have a wide range of applications in organic synthesis, medicinal chemistry, and materials industries.In chapter Ⅵ, the developments for fluorination of unsaturated carbon-carbon bonds, such as oxyfluorination, aminofluorination, hydrofluorination, phosphonofluorination and carbofluorina-tion of alkenes, allenes, and alkynes were briefly summed up and then an efficient method utilizing AgNO3 as the catalyst for the intermolecular fluoroacylation of styrenes through decarboxylation under mild reaction conditions has been developed. Tirdly, the reaction conditions wer optimized, and the scope of this reaction was investigated. Noteworthily, β-fluorinated aryl ketones demonstrate a plurality of biological activities and show great potential in medical chemistry.