C-SUBSTITUTION REACTIONS OF C,N-DIARYL NITRONES.

Article abstract of DOI:10.1016/S0040-4020(01)88625-7

C,N-Diaryl nitrones react rapidly with N-bromosuccinimide in an aprotic solvent to yield among other products, the E and Z isomers of the C-succinimidyl substituted nitrones and a small amount of the corresponding hydroxamic acid.The sterochemistry of the C-succinimidyl niyrones was confirmed by an X-ray structure determination of the C,N-(dimethoxyphenyl) derivative 8e.In the presence of the base DABCO the formation of hydroxamic acids is suppressed and the Z C-succinimidyl nitrone forms more rapidly than the more stable E isomer.Several mechanistic rationalisations of this observed stereochemistry are discussed.