New Cascade Syntheses of Nitronyl Nitroxides and a New Synthetic Approach to Imino Nitroxides

New Cascade Syntheses of Nitronyl Nitroxides and a New Synthetic Approach to Imino Nitroxides Full article

Journal

European Journal of Organic Chemistry
ISSN: 1434-193X

Output data

Year: 2009, Volume: 2009, Number: 15, Pages: 2548-2561 Pages count : 14 DOI: 10.1002/ejoc.200801237

Authors

Tretyakov Eugene ¹ , Tolstikov Svyatoslav ¹ , Mareev Aleksander ² , Medvedeva Alevtina ² , Romanenko Galina ¹ , Stass Dmitry ³ , Bogomyakov Artem ¹ , Ovcharenko Victor ¹

Affiliations

1	International Tomography Center, Siberian Branch, Russian Academy of Sciences, Institutskaya Str. 3a, 630090 Novosibirsk, Russian Federation, Fax: +7-383-3333455
2	A. E. Favorsky Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, Favorsky Str. 1, 664033 Irkutsk, Russian Federation
3	Institute of Chemical Kinetics and Combustion, Siberian Branch, Russian Academy of Sciences, Institutskaya Str. 3, 630090, Novosibirsk, Russian Federation

Suspensions of MxOy (MnO2,Co2O3,Ni2O3) in protic solvents (MeOH, EtOH) have been found to be suitable systems for use in a cascade transformation of 4,4,5,5-tetramethyl-2-[2(trimethylsilyl)ethynyl]imidazolidine-1,3-diol (1a) into 2-ethynyl-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyl 3oxide (3). In MnO2/MeOH, the products of further transformation of 3, (Z)- and (E)-2-(2-methoxyvinyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyl 3-oxides, were obtained by the regiospecific addition of MeOH to the triple bond of 3. In the reaction in MnO2/MeOH+H2O (1:1), the Z isomer was the sole product. A multistep one-pot transformation of 1 into 4,4,5,5-tetramethyl-2-[2-oxo-1-(4,4,5,5-tetramethylimidazolidin-2-ylidene)ethyl]-4,5-dihydro-1H-imidazole-1-oxyl 3-oxide occurred in MnO2/EtOH. For (E)-2-[2(diethylamino)vinyl]-4,4,5,5-tetramethyl-4,5-dihydro-1Himidazole-1-oxyl 3-oxide, it was shown that use of the MnO2/ secondary amine system provided a one-pot transformation of 1a and gave (E)-aminovinyl-substituted nitronyl nitroxide as the sole product. In combined MnO2/ROH/K2CO3 systems (R = Me, Et), the imidazolidine-1,3-diol 1a was transformed into (E)-2-(2-ethoxyvinyl)-4,4,5,5-tetramethyl-4,5-dihydro1H-imidazole-1-oxyl 3-oxide and the acetals 2-(2,2-dimethoxyethyl)- and 2-(2,2-diethoxyethyl)-4,4,5,5-tetramethyl-4,5dihydro-1H-imidazole-1-oxyl 3-oxide. In MnO2/MeNO2 we obtained the products of the transformations of different 2substituted 4,4,5,5-tetramethylimidazolidine-1,3-diols (R = C C–SiMe3, aryl, hetaryl, alkyl) or nitronyl nitroxides into the corresponding imino nitroxides (13 products); this reaction is a new method for the preparation of imino nitroxides and allowed us to synthesize the first α-acetylenyl-substituted imino nitroxides. The majority of paramagnetic compounds, including the derivatives of 1a, were obtained as perfect crystals, and their structures were determined by Xray structure analysis (14 solved structures).

Tretyakov E. , Tolstikov S. , Mareev A. , Medvedeva A. , Romanenko G. , Stass D. , Bogomyakov A. , Ovcharenko V.
New Cascade Syntheses of Nitronyl Nitroxides and a New Synthetic Approach to Imino Nitroxides
European Journal of Organic Chemistry. 2009. V.2009. N15. P.2548-2561. DOI: 10.1002/ejoc.200801237 WOS Scopus

Published online:

May 5, 2009

Web of science:	WOS:000266415300014
Scopus:	2-s2.0-66149098171

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Scopus	20
Web of science	21