Studies On Dioxygenation Of Alkenes Based On Clean-Oxidant

Dioxygenation of alkenes is one of the important field in organic chemistry, it has emerged as the most powerful method for the preparation of valuable 1,2-diols, which is not only an important motif in many drug molecules and biologically active natural products, but also as an valuable precursors in organic functional group conversion. Prevost-Woodward dihydroxylation, Upjohn syn dihydroxylation of alkenes along with its asymmetric version developed by Sharpless et al., has been elegantly demonstrated and widely used in organic synthesis. Unfortunately high cost and toxicity of metal complexes are neened usually with a large scale, which limits their applications on an industrial scale. Development of simple and efficient, environmentally friendly new methods of alkenes dioxygenation which adapt to industrial production is necessary.In this context, we have made two parts of work based on dioxygenation of alkenes, The details are summarized as following:Triflic acid-Catalyzed direct oxidative lactonization of alkenoic acids mediated solely by NaIO4 without halogen salts and metal. This protocol can easily synthesis of substituted five- or six-membered ring lactones, it also can obtain diacyloxylation products with liner alkenes.Direct dioxygenation of alkenes cooperatively catalyzed by tBuONO and palladium using clean and cheap air as sole oxidant at room temperature is also developed, providing a divergent access to various vicinal diols, diacetoxyalkanes and dihalogenoalkanes. As a synthetically practical method, gram-scale synthesis has also been provided. Vicinal dichlorolation and difluorination products could be achieved via this reaction, It’s valuable for synthesis.So, we developed two methods which are mild, efficient for dioxygenation of alkenes, These methods are environmentally benign and sustainable.