Cyclization of electrochemically generated nitrogen radicals. : A novel synthesis of 11-substituted dibenzo[a,d]cycloheptenimine derivatives

A novel and convenient synthesis of 11-substituted dibenzo[a,d]cyclo-heptimines 10 via annelatlon of electrochemically generated aminium radicals derived from substituted 5-hydroxylamino-5-methyl-5H-dibenzo[a,d]cycloheptenes 14 is described. The scope and limitations of the reaction as well as the effects of reactor design, current density and electrode material on the yield of 10 and the carbocation rearrangement by-product 28 are discussed. The synthesis of the title compounds was achieved by cyclization of the aminium radicals generated by anodic oxidation of substituted hydroxylamines.