Three-Component Heterocyclization of gem-Bromofluorocyclopropanes with NOBF4: Access to 4-Fluoropyrimidine N-Oxides
摘要:
Novel three-component heterocyclization involving gem-bromofluorocyclopropanes, nitrosyl tetrafluoroborate, and a molecule of the solvent (nitrile) yielding previously unknown fluorinated pyrimidine N-oxides is described. A two-step synthetic approach to 4-fluoropyrimidine N-oxides from alkenes under mild conditions is developed using this reaction. Mechanistic aspects of the heterocyclization are discussed.
A novel and effective approach to 4-fluoropyrimidines
作者:Kseniya N. Sedenkova、Elena B. Averina、Yuri K. Grishin、Tamara S. Kuznetsova、Nikolay S. Zefirov
DOI:10.1016/j.tetlet.2013.11.070
日期:2014.1
4-fluoropyrimidine 1-oxides, obtained via three-component heterocyclization, was studied under various reduction conditions. An effective preparative method for the synthesis of 4-fluoropyrimidines from readily available starting materials was elaborated. 4-Fluoro-substituted tetrahydroquinazolines and tetrahydroquinazoline N-oxides were demonstrated to be highly reactive in aromatic nucleophilic substitution.
Dichotomy in the reactivity of 2-methyltetrahydroquinazoline 1-oxides towards aldehydes: An unprecedented condensation with simultaneous reduction of the N-oxide fragment
作者:Kseniya N. Sedenkova、Alexey V. Terekhin、Irina V. Abdrashitova、Dmitry A. Vasilenko、Kirill S. Sadovnikov、Yulia A. Gracheva、Yuri K. Grishin、Tina Holt、Andrei G. Kutateladze、Tamara S. Kuznetsova、Elena R. Milaeva、Elena B. Averina
DOI:10.1016/j.tetlet.2020.151605
日期:2020.3
An unusual condensation reaction of 2-methyltetrahydroquinazoline N-oxides with aromaticaldehydes was found. The reaction of 4-cyano substituted heterocycles as well as the use of microwave irradiation for 4-morpholinyl substituted heterocycles resulted in the condensation engaging the methylene group of the tetrahydroquinazoline fragment with simultaneous deoxygenation of the N-oxide. A preparative