Bis(oxiranes) Containing Cyclooctane Core: Synthesis and Reactivity towards NaN₃

Reactions of oxirane ring opening provide a powerful tool for regio- and stereoselective synthesis of polyfunctional and heterocyclic compounds, widely used in organic chemistry and drug design. Cyclooctane, alongside other medium-sized rings, is of interest as a novel molecular platform for the construction of target-oriented leads. Additionally, cyclooctane derivatives are well known to be prone to transannular reactions, which makes them a promising object in the search for novel approaches to polycyclic structures. In the present work, a series of cyclooctanediones was studied in Corey-Chaykovsky reactions, and novel spirocyclic bis(oxiranes) containing cyclooctane core, namely, 1,5-dioxadispiro[2.0.2.6]dodecane and 1,8-dioxadispiro[2.3.2.3]dodecane, were synthesized. Ring opening of the obtained bis(oxiranes) upon treatment with sodium azide was investigated, and it was found that the reaction path is determined by the reciprocal orientation of oxygen atoms in the oxirane moieties. Diastereomers of the bis(oxiranes) with cis-orientation underwent independent ring opening, supplying corresponding diazidodiols, while in the case of stereoisomers with trans-orientation, domino-like reactions occurred, including intramolecular nucleophilic attack and the formation of a novel three- or six-membered O-containing ring. Summarily, a straightforward approach to polyfunctional compounds containing cyclooctane or oxabicyclo[3.3.1]nonane cores, employing bis(oxiranes), was elaborated

Three-Component Heterocyclization of <i>gem</i>-Bromofluorocyclopropanes with NOBF₄: Access to 4‑Fluoropyrimidine <i>N</i>‑Oxides

Novel three-component heterocyclization involving <i>gem</i>-bromofluorocyclopropanes, nitrosyl tetrafluoroborate, and a molecule of the solvent (nitrile) yielding previously unknown fluorinated pyrimidine <i>N</i>-oxides is described. A two-step synthetic approach to 4-fluoropyrimidine <i>N</i>-oxides from alkenes under mild conditions is developed using this reaction. Mechanistic aspects of the heterocyclization are discussed

Three-Component Heterocyclization of <i>gem</i>-Bromofluorocyclopropanes with NOBF₄: Access to 4‑Fluoropyrimidine <i>N</i>‑Oxides

Novel three-component heterocyclization involving <i>gem</i>-bromofluorocyclopropanes, nitrosyl tetrafluoroborate, and a molecule of the solvent (nitrile) yielding previously unknown fluorinated pyrimidine <i>N</i>-oxides is described. A two-step synthetic approach to 4-fluoropyrimidine <i>N</i>-oxides from alkenes under mild conditions is developed using this reaction. Mechanistic aspects of the heterocyclization are discussed

Three-Component Heterocyclization of <i>gem</i>-Bromofluorocyclopropanes with NOBF₄: Access to 4‑Fluoropyrimidine <i>N</i>‑Oxides

Novel three-component heterocyclization involving <i>gem</i>-bromofluorocyclopropanes, nitrosyl tetrafluoroborate, and a molecule of the solvent (nitrile) yielding previously unknown fluorinated pyrimidine <i>N</i>-oxides is described. A two-step synthetic approach to 4-fluoropyrimidine <i>N</i>-oxides from alkenes under mild conditions is developed using this reaction. Mechanistic aspects of the heterocyclization are discussed

A Facile Approach to Bis(isoxazoles), Promising Ligands of the AMPA Receptor

A convenient synthetic approach to novel functionalized bis(isoxazoles), the promising bivalent ligands of the AMPA receptor, was elaborated. It was based on the heterocyclization reactions of readily available electrophilic alkenes with the tetranitromethane-triethylamine complex. The structural diversity of the synthesized compounds was demonstrated. In the electrophysiological experiments using the patch clamp technique on Purkinje neurons, the compound 1,4-phenylenedi(methylene)bis(5-aminoisoxazole-3-carboxylate) was shown to be highly potent positive modulator of the AMPA receptor, potentiating kainate-induced currents up to 70% at 10−11 M