Rearrangements and cyclization-XVII: Mechanism of the formation of 1, 2-azoles in reactions of 1, 1-diacyclopropanes with hydrazine and hydroxylamine derivatives
NS Zefirov, SI Kozhushkov, TS Kuznetsova, BA Ershov…
The mechanism of recently discovered ring-opening reactions of 1, 1-diacyclopropanes with hydrazine and hydroxylamine derivatives is investigated using the 1H-NMR flow (and stopped-flow) method and transient formation of spiro-activated intermediates of type 4 and 19 is proved. The mechanistic and synthetic sequences of these findings are discussed.