Nitroxides (aminyl oxides) - XLI. Formation and dimerization of β-sulfonyl vinyl nitroxides. CC-versus OC-dimerization
作者:Hans Günter Aurich、Klaus-Dieter Möbus
DOI:10.1016/s0040-4020(01)89108-0
日期:1989.1
Upon oxidation of hydroxylamines 1a–c only nitrones 2a–c could be isolated although the nitroxides 3a–c were detected by ESR. Oxidation of 1f yields compound 5, the CC-dimer of 4. Whereas oxidation of 1d affords only 7d which arises from 3d by CC-dimerization and elimination of propylsulfinic acid, from vinyl nitroxide 3e products 7e,8 and 9 are formed by CC-dimerization and subsequent reaction steps
Nitroxides (aminyl oxydes) - XL. ESR spectroscopic studies of β-sulfonyl substituted vinyl nitroxides and of a vinylogous nitronyl nitroxide
作者:Hans Günter Aurich、Klaus-Dieter Möbus
DOI:10.1016/s0040-4020(01)89107-9
日期:1989.1
Oxidation of hydroxylamines 1 affords the vinyl nitroxides 4 via 2 and 3. The vinylogous nitronyl nitroxide 5 is formed upon oxidation of 1h. Whereas the methyl group X in 4a is freely rotating, rotation of substituents X in 4b–d is restricted as is indicated by their ESR spectra. Particularly, the less hindered vinyl nitroxides 4e–g form spin adducts 6 or 7 with their precursor nitrones 3. 4b coexists