130995-62-9Relevant articles and documents
Rearrangement Reactions of Oxaziridines to Nitrones. X-Ray Crystal and Molecular Structure of N-t-Butyl-α(o-hydroxyphenyl)nitrone
Christensen, Dorthe,Jorgensen, Karl Anker,Hazell, Rita G.
, p. 2391 - 2397 (2007/10/02)
Substituted N-benzylidene-t-butylamines are oxidized with m-chloroperoxybenzoic acid to oxaziridines which can rearrange to the corresponding nitrones when electron-donating groups are present in the phenyl ring.The oxaziridine-to-nitrone rearrangement, which has been considered as a 'pseudo-abnormal' reaction, can also be catalysed by Lewis acids.It has been found that the rearrangement of 2-t-butyl-3-(o-hydroxyphenyl)oxaziridine to the corresponding nitrone is of first order.The rearrangement has been investigated for different substituents in the phenyl ring, andin the case of 2-t-butyl-3-phenyloxaziridine substituted in the ortho position with electron-donating groups it has been found that the presence of protons of a Lewis acid is necessary.An X-ray structure of α-(o-hydroxyphenyl)-N-t-butylnitrone shows strong hydrogen bonding between the nitrone oxygen and the hydrogen in the hydroxy group.The oxaziridine-to-nitrone rearrangement is also analysed from a theoretical point of view using ab initio calculations.A Mulliken-population analysis of the C-O and N-O bonds in the oxaziridine ring for para-substitued 2-t-butyl-3-phenyloxaziridines shows a reduction of the C-O bond population when an electron-donating group is present in the para position of the phenyl ring compared with an electron-withdrawing group; the N-O bond populations show the reverse picture.A state-correlation diagram for the oxaziridine-to-nitrone rearrangement is also presented and the experimental and theoretical results support each other.