Copper-Catalyzed Cyclization Of Unsaturated Oximes

This thesis deals with the copper-catalyzed cyclization of unsaturated oximes. It contains three parts.In the first section, the recent progress made in the field of C-N bond forming reactions involving the N-O cleavage of oxime derivatives is reviewed. The related literature works are summarized according to the reaction types and mechanisms.The second and the third section describe my research works during the period of my graduate study. They are summarized as follows.(1) A preliminary mechanistic investigation has been conducted concerning the copper catalyzed cyclization of y,8-unsaturated oximes. The reaction of γ,δ-unsaturated O-benzoyl and acetoxy oximes were carried out under a variety of conditions, and by analyzing the composition of the products and through radical clock experiment, we obtained the concrete evidence about the generation of free radical intermediates in the cyclization process.(2) The copper-catalyzed cyclization/pentafluorobenzoyloxy group transfer reaction of y,8-unsaturated O-pentafluorobenzoyl oximes has been investigated. We found that by using CuPF6as catalyst, γ,δ-unsaturated O-pentafluorobenzoyl oximes underwent N-O cleavage, followed by imine attack on the carbon-carbon double bond to give the dihydropyrrole ring. The cleavaged pentafluorobenzoyloxy group was attached to the olefin group after cyclization. The ligand has a big influence on the reaction.With ethyl2-oxocyclohexanecarboxylate as the ligand, the desired dihydropyrrole products can be obtained in good yields. By using this protocol, the cyclization/oxyamination of y,8-unsaturated O-pentafluorobenzoyl oximes can be accomplished in an atom economical fashion.