Radical-Initiated 1,2-Difunctionalization Of Alkenes

Difunctionalization of alkenes is one of the most important methods in organic synthesis, which can transform alkenes into various biologically active compounds and natural products, and represents a powerful way to the construction of chemical structure diversity.Generally, the alkene difunctionalization transformations are mainly focus on transition metal-catalyzed carboamination, carbooxygenation, sulfuooximation halosulfonylation; however, the aminosulfonylation of alkenes are quite rare. In addition, the difunctionalization reactions of N-(arylsulfonyl) alkenes have attracted increasing interest in recent years. Therefore, the development of new routes to transformation of alkenes through the difunctionalization strategy is very desirable.This dissertation mainly studies on two parts of content, including i) the copper-catalyzed oxidative difunctionalization of alkenes with tert-Butyl nitrite and aryl sodium sulfonate and ii) ruthenium-catalyzed difunctionalization of N-(aryl sulfonyl)alkenes diazonium salts by 1,4-aryl migration. The contents of this dissertation include as following:(1) In chapter 1, recent progress in the difunctionalization reactions of alkenes has been summarized in detail. We discussed the recent progress, including (i) the carboamination of alkenes, (ii) the carbooxygenation of alkenes, (iii) the aminooxygenation of alkenes, (iv) the sulfuooximation of alkenes, (v) the halosulfonylation of alkenes and (vi) aminosulfonylation of alkenes. The results and the mechanisms of transition metal catalysis were mainly described.(2) In chapter 2, a novel copper-mediated intermolecular three-component difunctionalization of alkenes for the synthesis of a-sulfonylethanone oximes using arylalkenes, sodium arylsulfinates and tert-butyl nitrite (TBN) is described. This radical-mediated method enables the formation of C-N and C-S bonds in a single step under mild conditions, and provides a straightforward access to ?-sulfonylethanone oximes. Moeover, the reaction mechanism was also discussed in detail.(3) In chapter 3, an efficient ruthenium-catalyzed oxidative difunctionalization of N-(arylsulfonyl)alkenes with aryldiazonium salts for the selective synthesis of acylic and cyclic quaternary stereocenters has been developed, which proceeds via a 1,4-aryl migration process.