Studies On The Photoinduced Electron Transfer Catalyzed [3+2] Cycloaddition Reactions Between Epoxides And Olefins

The synthetic potential of photoinduced electron transfer (PET)-catalyzed reactions has attracted great attention in the past two decades. This thesis was mainly focused on the photoinduced electron transfer catalyzed cycloaddition reaction of aryl-substituted epoxides with olefins. It consists of two parts:The first part of this thesis is a concise introduction of photoinduced electron transfer reaction and a review on synthetic application of photoinduced electron transfer reactions and the application of sensitizer TPT (2,4,6-Triphenypyrylium Tetra flouroborate) in promoting a variety of photoinduced electron transfer reactions.The second part is the report of my research work. I examined the TPT-sensitized cycloaddition reaction of methoxyphenyl-subistituted oxiranecarbonitriles (1a-f) with electron-rich olefins such as styrene(2a), a-methylstyrene(2b), indene(2c), cyclopentene(2d). I found the ring opening of epoxides were via selective C_β-O bond cleavage and subsequent [3+2] cycloaddition with electron-rich olefins produced the main products tetrahydrofuran derivatives. The reaction was completely stereoselectivity.