New Way to Substitute Tetracyanocyclopropanes: One-Pot Cascade Assembling of Carbonyls and Malononitrile by the Only Bromine Direct Action

Table 1

Direct transformation of benzaldehyde 1a, butanal 1k and cyclohexanone 1p with malononitrile 3 into substituted 1,1,2,2-tetracyanocyclopropanes 2 .

Carbonyl	Solvent	Bromine	Catalyst	Yield of (%)
1a	EtOH	elemental	—	2a, 12
1a	EtOH/H2O	0.2 M (H2O)	—	2a, 90
1a	EtOH/H2O	0.2 M (H2O)	NaOAc	2a, 92
1k	EtOH/H2O	0.2 M (H2O)	—	2k, 21
1k	EtOH/H2O	0.2 M (H2O)	NaOAc	2k, 86
1p	EtOH/H2O	0.2 M (H2O)	—	2p, 43
1p	EtOH/H2O	0.2 M (H2O)	NaOAc	2p, 79

10 mmol of carbonyl compound 1, 20 mmol of malononitrile 3, 5 mmol of NaOAc, 20 mL of EtOH, 50 mL of 0.2 M Br₂ in water (10 mmol), temperature 40°C, time of reaction 1 hour.
Yield of isolated product.