96406-49-4

Upstream product

• 16649-50-6 N-tert-Butylhydroxylamine 
• 769-60-8 2-methyl-1-phenylprop-2-en-1-one 

Downstream Products

• 116375-79-2 C₂₈H₃₆N₂O₄ 

Relevant academic research and scientific papers

Formation of Polycyclic Dimers from Vinyl Nitroxides and Their Dissociation and Isomerization

The ambiphilic vinyl nitroxides (VN) 6 dimerize, affording either tricyclic dimers (TRI-DI) 8 or bicyclic dimers (BI-DI) 7.Formation of 8 is rationalized by C-C bond formation followed by an intramolecular (3 + 2 + 2) cycloaddition involving one nitrone and two carbonyl groups, whereas 7 must arise from O-C bond formation followed by an intramolecular (3 + 2) cycloaddition of nitrone and alkene moiety.Since the BI-DIs 7 are the thermodynamically more stable dimers, the course of the reaction depends on the question of whether it is possible to overcome the activation barrier for its formation.The crucial reaction step, the 1,3 dipolar cycloaddition involving the nitrone and alkene moiety, is favored by N-phenyl substitution and retarded by N-tert-butyl substitution of the nitrone group.Thus, BI-DIs 7 arise from N-phenyl-substituted VNs, whereas VNs with R1 = tert-butyl yield TRI-DIs 8 at room temperature.Most of the TRI-DIs 8 dissociate at room temperature or slightly elevated temperatures.Dissociation is favored either by steric congestion of 8 or by enhanced stabilization of the acyl group R3CO of the VNs 6.Tetracyclic dimers (TET-DI) 12 arise from TRI-DIs 8 in refluxing methanol or in the presence of acids at room temperature.Isomerization in aprotic solvents in the absence of acids requires higher temperatures.Under these conditions formation of TET-DIs 12 is frequently accompanied by formation of BI-DIs 7 which must be formed via the VNs 6.

Aminyl Oxides (Nitroxides), XXXVII. Formation of Vinylaminyl Oxides Substituted by Electron-Acceptor Groups and Related Radicals as Studied by ESR Spectroscopy

Vinylaminyl oxides substituted by electron-acceptor groups at β-position have been prepared by various methods.Oxidation of nitrones 6 or the tautomeric N-vinylhydroxylamines 7 yields radicals 8a, b, z, and ae. 8 oe and ue arise from oxidation of the isoxazolines generated in situ from the isoxazolium salts 12.The bisvinylaminyl oxides 16 and 17 are prepared by oxidation of the corresponding N,N-bisvinylhydroxylamines.Oxidation of N,N-disubstituted hydroxylamines 10 or 14 affords initially aminyl oxides 11 or 15 which are further dehydrogenated to the vinylaminyl oxides 8a, l, m, o - t, x, y, and 2a - c, respectively. - With the exception of 8a and b vinylaminyl oxides could be detected only if there is a second substituent as a phenyl group, a second electron-acceptor group or a methylthio-, phenylthio-, or phenylseleno group at the β-position.Monosubstituted vinylaminyl oxides undergo a spin-trap reaction with their precursor nitrone to give spin adduct 19 or 20.