Generation of Stable Biradical Intermediates in Intramolecular Photo-Cycloaddition of Aromatic Compounds

点击翻译按钮获取中文摘要

In order to establish the highly stereo and peri-selective in an aromatic photo-cycloaddition and to elucidate the involvementof biradical intermediates, photochemical reactin of N-naphthamides and N-cimmamides were examined.,(1) Inter- and Intra- molecular selection of photo-cycloaddition ; In the photo-cycloadditin of N-cimmanoylnaphthamides, the intramolecular cycloaddion occurred in solution and the intermolecular cycloadition was achieved in the solid state reaction depending on the substituents.(2) The control of the peri-selectivity ; This was achieved in the photo-cycloaddition of N-1- (1-naphthyl) ethyl-cimmamides and N-1- (1-naphthyl) ethylacryl amides. In the former, the intramoleclar [4+2] cycloaddition was achieved and the [2+2] cycloaddition was achieved in the latter.(3) Novel [2+2] photo-cycloaddition of a benzene ring with an enone double bond ; This rare example of the [2+2] photo-cycloaddition was observed in N-benzoylcimmamides.(4) Generation of a biradical intermediate and its trapping with molecular oxygen ; The 1,8 biradical intermediate was generated in the intramolecular photo-cycloaddition of N-naphthoylnaphtamides. The generated biradical intermediate was efficiently trapped with molecular oxygen. The life time of the intermedaite was determined by laser flash photolysis.(5) Asymmetric photo [4+4] cycloaddition ; The first example of an absolute asymmetric synthesis in aromatic photo-cycloaddion was achieved in the solid-state photochemistry of N-anthronylnaphthamieds.