Table 3. Synthesis of a(1–12) by E^a.

^aReaction conditions: 5-amino tetrazole (1 mmol), 4-chloroaldehyde (1 mmol), dimedone (1 mmol), E (10 mg) in solvent-free condition, at 70 °C.

^bIsolated yield.

^cTON (turnover number): based on the ICP measurements at a ratio of 1 : 4, the content of Co in the catalyst is about 30.54, so the mmole of Co in 10 mg of the catalyst is 0.3 mmole g⁻¹. For entry 1, since the yield is about 78%, the effective mmole the TON is 0.78 ÷ 0.3 = 2.6.

^dTOF (turnover frequency): TOF = TON ÷ time. For entry 1, since the time is about 30 min, the TOF is 2.6 ÷ 30 = 0.08.