Chemical Reactivity of Dihydropyrazine Derivatives. Cycloaddition Behavior toward Ketenes
نویسندگان
چکیده
منابع مشابه
Chemical reactivity of dihydropyrazine derivatives. Cycloaddition behavior toward ketenes.
The cycloaddition behavior of dihydropyrazines toward ketenes was investigated using single-crystal X-ray structures of the cycloadducts and density functional theory (DFT) calculation data. The reaction proceeds via a stepwise pathway involving an orientation complex prior to formation of the betaine intermediate. This is followed by electrocyclization to afford the 1 : 1 and 1 : 2 adducts bea...
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A reactivity model for concerted cycloaddition reactions is presented which allows a systematization of substituent effects. The treatment is based on the frontier electron theory of Fukui. The consideration of the energy separations of HOMOs (Highest Occupied Molecular Orbitals) and LUMOs (Lowest Unoccupied Molecular Orbitals) leads to three reactivity types in these cycloadditions. For the Di...
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ژورنال
عنوان ژورنال: Chemical and Pharmaceutical Bulletin
سال: 2009
ISSN: 0009-2363,1347-5223
DOI: 10.1248/cpb.57.846