Construction of bis-, tris- and tetrahydrazones by addition of azoalkenes to amines and ammonia

• Artem N. Semakin,
• Aleksandr O. Kokuev,
• Yulia V. Nelyubina,
• Alexey Yu. Sukhorukov,
• Petr A. Zhmurov,
• Sema L. Ioffe and
• Vladimir A. Tartakovsky

Beilstein J. Org. Chem. 2016, 12, 2471–2477, doi:10.3762/bjoc.12.241

• -tetraazaadamantane derivative was demonstrated. Keywords: azoalkenes; α-halogen hydrazones; heterocage compounds; hydrazone ligands; Michael addition; Introduction Hydrazones are extensively used as key structural units in the design of various functional molecular and supramolecular architectures [1][2][3][4][5

• hydrazones with starting hydrazide [51]. The presence of acetic acid and mild reaction conditions (0 °C) was essential for the synthesis of hydrazones 1c and 1d (R1 = CH3, R2 = CH3 or (CH2)6CH3), probably because of the their enhanced NH-acidity. Reaction of α-halogen hydrazones 1 with benzylamine In our

• carbonate as a base in MeOH led to bishydrazone 2a in highest yield. The bright yellow color appeared in course of reagents mixing indicating the formation of azoalkene intermediate A [35][36][37][38][39]. Under these conditions, a range of other α-halogen hydrazones 1b–d,f,g were successfully converted to