10.1021/acs.joc.8b00069.s001
Kirill
I. Mikhailov
Kirill
I.
Mikhailov
Ekaterina E. Galenko
Ekaterina E.
Galenko
Alexey V. Galenko
Alexey V.
Galenko
Mikhail S. Novikov
Mikhail S.
Novikov
Alexander Yu. Ivanov
Alexander Yu.
Ivanov
Galina L. Starova
Galina L.
Starova
Alexander F. Khlebnikov
Alexander F.
Khlebnikov
Fe(II)-Catalyzed Isomerization
of 5‑Chloroisoxazoles
to 2<i>H</i>‑Azirine-2-carbonyl Chlorides as a Key
Stage in the Synthesis of Pyrazole–Nitrogen Heterocycle Dyads
American Chemical Society
2018
2 H
Pyrazol -1-ylcarbonyl H
azirine -2-carbonyl chlorides
pyrrol -2-ylcarbonyl H
Fe
DFT
azirine -2-carbonyl chloride
Pyrazol -1-yl show
pyrazole
2018-02-15 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Fe_II_-Catalyzed_Isomerization_of_5_Chloroisoxazoles_to_2_i_H_i_Azirine-2-carbonyl_Chlorides_as_a_Key_Stage_in_the_Synthesis_of_Pyrazole_Nitrogen_Heterocycle_Dyads/5936164
2-(1<i>H</i>-Pyrazol-1-ylcarbonyl)-2<i>H</i>-azirines were synthesized by in situ trapping of 2<i>H</i>-azirine-2-carbonyl chlorides, generated by Fe(II)-catalyzed
isomerization
of 5-chloroisoxazoles, with pyrazoles. According to DFT calculations,
the selectivity of nucleophilic substitution at the carbonyl group
of 2<i>H</i>-azirine-2-carbonyl chloride by a pyrazole nucleophile,
which is a mixture of two tautomers, is controlled by thermodynamic
factors. 2-(1<i>H</i>-Pyrazol-1-ylcarbonyl)-2<i>H</i>-azirines are excellent precursors for the preparation of two other
pyrazole–nitrogen heterocycle dyads: 5-(1<i>H</i>-pyrazol-1-yl)oxazoles by photolysis and 1-(1<i>H</i>-pyrrol-2-ylcarbonyl)-1<i>H</i>-pyrazoles by a Ni(II)-catalyzed reaction with 1,3-dicarbonyl
compounds. 5-(1<i>H</i>-Pyrazol-1-yl)oxazoles show strong
emission in acetonitrile at 360–410 nm with high quantum yields.