Study On The Hydroazidation Of Alkynes

Vinyl azide compounds are one kind of olefins containing carbon-carbon double bond and azide unit. They are becoming one of important synthons in building carbon-carbon bond and carbon-nitrogen bond. The parent compound of vinyl azide has been known for about one hundred years when Foster prepared it. However, conventional accesses to this kind of compounds have a lot of disadvantages such as complex operations, low yields and poor stereoselectivity. It has seriously hampered the wide exploitation of their synthetic potential. The hydroazidation of alkynes is an ideal way to obtain alkenyl azides. However, known variety transformations are nearly all restricted to the addition of azide species to alkynes with electron-withdrawing group and show poor regioselectivity. With regard to unactivated alkynes, only two examples have been isolated in previous reports. It is a important and challenging issue in developing a general method for the hydroazidation of inactive alkynes. We achieved series of publications in alkyne reactions in presence of metal catalyst, which gives the foundation to create the hydroazidation of inert alkynes.Although metal catalysts play a unique advantages in application of vinyl azides to obtain nitrogen-heterocycles, metal-free reactions get more attention with our persue of new applicaitions of vinyl azides and green chemistry. At this time, vinyl azides have attracted great interesting because of high natural reactivity without catalysis and quickly become a frontier area in organic chemistry research. Developing new metal-free reaction of alkenyl azides is in line with the aim of the modern synthetic chemistry. To solve these problems, we carried out the corresponding research work and obtained series of good results.My thesis is divided into five chapters.Chapter 1: synthetic methods of vinyl azides.Chapter2 : the progress of vinyl azide applications.Chapter 3: the paper topic.Chapter 4: build the hydroazidation of alkynes with the silver catalyst.It describes a high efficient and regioselectivity synthesis to vinyl azides. It is a breakthrough for the chemistry of hydroazidation of inert alkynes.Chapter 5: develop the devinylazidative allylation reaction.We construct the carbon-carbon bond with alkenyl azides and allyl reagent through intercepted Schmidt rearrangement in the condition of acid,in which vinyl azides serve as carbocation electrophile. It shows a new direction of vinyl azide aplication.