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

Table 2

Direct transformation of carbonyl compounds 1a–r and malononitrile 3 into substituted 1,1,2,2-tetracyanocyclopropanes 2a–r by the action of bromine in EtOH/water system.

Olefin	R^1	R^2	Product	Yield of (%)
1a	H	Ph	2a	92
1b	H	4-MeC6H4	2b	91
1c	H	4-MeOC6H4	2c	93
1d	H	3-MeOC6H4	2d	91
1e	H	2-MeOC6H4	2e	92
1f	H	4-FC6H4	2f	90
1g	H	4-ClC6H4	2g	85
1h	H	3-ClC6H4	2h	87
1i	H	3-BrC6H4	2i	92
1j	H	4-NO2C6H4	2j	88
1k	H	n-Pr	2k	86
1l	Me	Me	2l	55
1m	Me	Et	2m	52
1n	Et	Et	2n	48
1o	– (CH2)4–		2o	69
1p	– (CH2)5–		2p	75
1r	– (CH2)6–		2r	67

10 mmol of carbonyl compound 1, 20 mmol of malononitrile 3, 3 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.