AZIDE AND FLUORIDE EXCHANGE REACTIONS OF HALODIAZIRINES

Article abstract of DOI:10.1021/ja00295a029

Reactions of 3-aryl-3-bromodiazirines (11) with molten tetrabutylammonium fluoride at 25^degC provide 65-74percent isolated vields of the novel corresponding 3-aryl-3-fluorodiazirines (12) Related reactions of 11 with tetrabutylammonium azide afford high yields of aryl nitriles.The latter reactions are believed to proceed through unstable intermediate 3-aryl-3-azidodiazirines (7).These reactions involve rate-determining formation of 7 and display kinetics which are first order in azide ion and bromodiazirine.The likely intermediacy of aryldiazirinium bromide ion pair between 11 and 7 is supported by a combination of salt effect, leaving group effect and Hammett studies.Molecular orbital calculations are employed to characterize azidodiazirines as well as the mode of their decomposition to nitriles.In particular, we consider the possible itermediacy of a 3-nitrenodiazirine or an azidocarbene.