Copper-Catalyzed Reaction of N-Monosubstituted Hydrazones with CBr4: Unexpected Fragmentation and Mechanistic Study

The copper catalyzed reaction of N-monosubstituted hydrazones with carbon tetrabromide leads to formation expected dibromodiazadienes and unexpected dibromostyrenes. experimental theoretical study the revealed a key role N-centered radicals, which can eliminate aryl radicals form corresponding Alternatively, oxidation intermediate by Cu(II) results in diazadienes. These two pathways are competitive directions reaction. Consequently, be useful for synthesis both dibromostyrenes rare dibromodiazadienes.