TY - JOUR

T1 - Interaction of a lithiated nitronyl nitroxide with polyfluorinated 1,4-naphthoquinones

AU - Zhivetyeva, S. I.

AU - Zayakin, I. A.

AU - Bagryanskaya, I. Yu

AU - Zaytseva, E. V.

AU - Bagryanskaya, E. G.

AU - Tretyakov, E. V.

N1 - Funding Information: This work was financially supported by the Russian Science Foundation (project No. 17-73-10238 ). The authors would like to acknowledge the Multi-Access Chemical Service Center SB RAS for spectral and analytical measurements. Publisher Copyright: © 2018 Elsevier Ltd

PY - 2018/7/12

Y1 - 2018/7/12

N2 - A 4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl lithium derivative was found to react with 2-methoxypentafluoro-1,4-naphthoquinone to form a product of addition at the carbonyl function: radical 2-(3,5,6,7,8-pentafluoro-1-hydroxy-2-methoxy-4-oxo-1,4-dihydronaphthalen-1-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl. The yield of the addition product increased with temperature and reached 84% at 0 °C. The reaction of the lithium derivative with hexafluoro-1,4-naphthoquinone gave rise to a product of addition at both carbonyl groups, namely, nitronyl nitroxide diradical 2,3,5,6,7,8-hexafluoro-1,4-bis(4,4,5,5-tetramethyl-3-oxide-1-oxyl-4,5-dihydro-1H-imidazole-2-yl)-1,4-dihydronaphthalene-1,4-diol in a 16% yield. The structures of both mono- and diradical were solved by X-ray diffraction analysis, which revealed formation of an intramolecular H-bond between the OH group and nitroxide oxygen. According to electron paramagnetic resonance (EPR) spectroscopy, the obtained mono- and dinitroxide are prone to spontaneous deoxygenation in a toluene solution to give corresponding iminonitroxides. In water, they are much more stable.

AB - A 4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl lithium derivative was found to react with 2-methoxypentafluoro-1,4-naphthoquinone to form a product of addition at the carbonyl function: radical 2-(3,5,6,7,8-pentafluoro-1-hydroxy-2-methoxy-4-oxo-1,4-dihydronaphthalen-1-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl. The yield of the addition product increased with temperature and reached 84% at 0 °C. The reaction of the lithium derivative with hexafluoro-1,4-naphthoquinone gave rise to a product of addition at both carbonyl groups, namely, nitronyl nitroxide diradical 2,3,5,6,7,8-hexafluoro-1,4-bis(4,4,5,5-tetramethyl-3-oxide-1-oxyl-4,5-dihydro-1H-imidazole-2-yl)-1,4-dihydronaphthalene-1,4-diol in a 16% yield. The structures of both mono- and diradical were solved by X-ray diffraction analysis, which revealed formation of an intramolecular H-bond between the OH group and nitroxide oxygen. According to electron paramagnetic resonance (EPR) spectroscopy, the obtained mono- and dinitroxide are prone to spontaneous deoxygenation in a toluene solution to give corresponding iminonitroxides. In water, they are much more stable.

KW - 1,4-Naphthoquinones

KW - ESR spectra

KW - Iminonitroxides

KW - Nitronyl nitroxides

KW - Organic diradicals

KW - X-ray diffraction study

KW - SUBSTITUTION

KW - DESIGN

KW - HYDROGEN-BONDS

KW - ORGANIC MOLECULAR-SOLIDS

KW - BIRADICALS

KW - FERROMAGNETIC INTERACTIONS

KW - RADICALS

KW - DERIVATIVES

KW - CYTOTOXICITY

UR - http://www.scopus.com/inward/record.url?scp=85048315684&partnerID=8YFLogxK

U2 - 10.1016/j.tet.2018.05.075

DO - 10.1016/j.tet.2018.05.075

M3 - Article

AN - SCOPUS:85048315684

VL - 74

SP - 3924

EP - 3930

JO - Tetrahedron

JF - Tetrahedron

SN - 0040-4020

IS - 28

ER -