Addition reactions of aminium radicals: synthetic studies of oxidative photoaddition of N-nitrodimethylamine (NNOD)

Abstract

Photoadditions of NNOD to various olefins under oxygen lead to 2-dimethylamino-1-nitrate esters in good yields as primary products. The amino-nitrates are stable in acidic solution but their stability towards bases varies over a wide range depending on configuration. In most cases, the crude photoaddition products were reduced with lithium aluminium hydride to give good yields of the alcohols. The nitrates derived from cyclododeca-1,5,9-trienes were stable and reduced by lithium aluminium hydride to give, quite unexpectedly, the acyclic α,ω-dimethylamino-alcohols. The oxidative photoaddition to cis,trans,trans-cyclododecatriene occurred preferentially at the trans-double bond and that to dicyclopentadiene at the norbornene double bond. In both cases, good regioselectivity was observed. The precursors to the nitrates were suggested to be the corresponding peroxynitrites which might also undergo various ionic or light-induced reactions.