Study On Silver-Catalyzed Reactions Of Isocyanides

The development of synthesis complex molecules from commercial materials is an important research focus in organic chemistry. Isocyanides and alkynes are two simple commercial materials, but how to implement these two simple molecules convert to the complex molecules skeletons is a huge challenge. Since Sasaki and co-works realized the [3+2] cyclization of isocyanides with activated alkynes for the first time (in other words, preparing 2,3,4-trisubstituted pyrroles with a relatively low yield), the reaction has attracted a wide attention for scientific workers. After nearly 30 years later, Yamamoto and de Meijere with their co-works made the [3+2] cyclization reaction of activated alkynes with isocyanides come true efficiently via copper-catalyzed. However, there were no reports about the cyclization of isocyanides with unactivated alkyne, thus, it becomes a great chance and challenge. Moreover, finding suitable catalyst and developing the novel and efficient reaction are high necessary. As the development of metal-organic-chemistry, the silver in the catalytic reaction of alkyne showed highly catalytic activity with good chemo-, regio-, and stereoselectivity etc. We will explore the cyclization reaction between isocyanides and unactivated alkyne via silver-catalyzed and change the structure of the substrate to achieve the diversity of reaction.On the other hand, isocyanides as the important organic blocks are often used to synthesize a series of nitrogen heterocyclic compounds, active molecules and natural products. The character of isocyanides is similar to CO which has strong coordination ability, it can involve the transition-metal-catalyzed reaction effectively. However, due to this ability the reactions of isocyanides always contain the uncontrollable overinsertion. Our team has been committed to the silver-catalyzed-chemistry of isocyanides and reported a series of research achievement. These findings are the foundation for us to develop the new reaction models and synthesis of heterocyclic compounds of isocyanides.My thesis is divided into six chapters.Chapter 1:Introduction on the silver-catalyzed reactions.Chapter 2:Introduction on the reactions of isocyanides.Chapter 3:The paper topic.Chapter 4:The silver-catalyzed reactions of isocyanides and alkynesFor the first time, the sliver-catalyzed [3+2] cycloaddition of isocyanides with unactivated terminal alkynes has been realized, thus establishing a fundamental reaction to give pyrroles with a broad range and high yields, and a novel mechanism of radical was proposed combined with the DFT calculations.Chapter 5:The silver-catalyzed reactions of isocyanides and propargylic alcoholsAn unprecedented cross-coupling of propargylic alcohols with isocyanides containing oxygen transposition relying on silver catalysis has been achieved and prepared 2,3-allenamides with excellent yields. Providing an efficient synthetic route to 2,3-allenamides.Meanwhile, We have developed a novel silver-catalyzed heteroaromatization reaction of propargylic alcohols with TosMIC and synthesised a range of functionalized benzoheteroles. For the first time, the role of TosMIC was found to be twofold, as the sulfonylsource and ligand.Chapter 6:The Silver-catalyzed cross-coupling of isocyanides and active methylene compoundsAn intriguing radical coupling reaction between active methylene compounds and isocyanides has been developed for the first time count on silver-catalyzed, which breaks the radical reaction limitations of cyclization. The over-insertion of isocyanides has been skillfully avoided and synthesized ?-aminoenones and tricarbonylmethanes with a broad range.