One-Pot Formation of 1,3,4-Oxadiazol-2(3H)-ones and Dibenzo[c,e]azepines by Concomitant Cathodic Reduction of Diazonium Salts and Phenanthrenequinones
摘要:
The one-pot concomitant electrochemical reduction of phenanthrenequinones (1, 2) and arenediazonium salts (3a-f) led to the formation of 1,3,4-oxadiazol-2(3H)-ones (4a-f, 5a) and dibenzo[c,e]azepines (6a-f) when N-methylformamide was used as the solvent. A new pathway, different from those previously described with other aprotic solvents, is proposed. The experimental data support a radical mechanism for the electrochemical process followed by an internal rearrangement to give the products.