General Procedure and spectra data
A 5-mL round bottomed flask was charged with the carbonyl compound (1.0 mmol), active methylene
compound (1.0 mmol), catalyst DABCO (12 mg, 10 mol % of the substrates) and water (0.5 mL). The
reaction mixture was stirred at the room temperature. The formation of the products was monitored by
TLC. After completion of the reaction, the reaction mixture often solidified in the round bottomed flask.
The solid mixture was filtered and washed with cold water to remove the catalyst, and then dried to
obtain the products. In general, no further purification method was required. All the products were
previously reported and were characterized by melting point determination and 1HNMR spectroscopy.
The catalyst was recovered by removing the water of the filtrate and reused in the reaction for six times.
In the case of liquid products, GC was used for yield determination. Selected data for typical
compounds are given below.
2-(Phenylmethylene)malononitrile (3a)
White solid, mp. 83-84 ℃. 1H NMR (400 MHz, CDCl3): δ 7.55 (2H, t, J= 8.0 Hz, ArH), 7.64 (1H, t, J= 7.6Hz,
ArH), 7.78 (1H, s, ArH), 7.92 (2H, d, J= 7.6Hz, ArH).
2-(4-Methylphenylmethylene)malononitrile (3b)
White solid, mp. 133-134 ℃. 1H NMR (400 MHz, CDCl3): δ 2.45 (2H, s, CH3), 7.35 (2H, d, J= 8.0 Hz, ArH),
7.22 (1H, s, ArH), 7.82 (2H, d, J= 8.0Hz, ArH).
2-(4-nitrobenzylidene)malononitrile (3c)
1
Yellow solid, mp. 161-162 ℃. H NMR (400 MHz, CDCl3): δ 7.88 (1H, s, =CH), 8.07 (2H, d, J= 8.8 Hz,
ArH), 8.39 (2H, d, J= 8.8Hz, ArH).
2-(4-chlorobenzylidene)malononitrile (3d)
White solid, mp. 164-165 ℃. 1H NMR (400 MHz, CDCl3): δ 7.52 (2H, d, J= 8.4 Hz, ArH), 7.73 (1H, s, =CH),
7.87 (2H, d, J= 8.4Hz, ArH).
2-((naphthalen-4-yl)methylene)malononitrile (3e)
1
White solid, mp. 113-114 ℃. H NMR (400 MHz, CDCl3): δ 7.59-7.70 (3H, m, ArH), 7.96 (2H, d, J= 2.4Hz,
ArH), 8.12 (1H, d, J= 8.0Hz, ArH), 8.27 (2H, d, J= 7.2Hz, ArH), 8.65 (1H, s, =CH).
2-(2-Furylmethylene)malononitrile (3f)
Red solid, mp. 69-70 ℃. 1H NMR (400 MHz, CDCl3): δ 6.73 (1H, dd, J1= 1.6Hz, J2= 3.6Hz, ArH), 7.35 (1H,
d, J= 3.6Hz, ArH), 7.53 (1H, s, =CH), 7.82 (1H, d, J= 1.2Hz, ArH).
2-(Cyclohexylidene)malononitrile (3i)
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Colourless liquid. H NMR (400 MHz, CDCl3): δ 1.65-1.73 (2H, m), 1.77-1.84 (4H, m), 2.66 (4H, t, J=
6.0Hz).
2-(Butan-2-ylidene)malononitrile (3j)
1
Colourless liquid. H NMR (400 MHz, CDCl3): δ 1.21 (3H, t, J= 7.6Hz, CH2CH3), 2.29 (3H, s, CCH3), 2.62
(2H, q, J= 7.6Hz, CH2CH3).
(E)-ethyl-3-phenyl-2-cyanoacrylate (5a)
White solid, mp. 48-49 ℃. 1H NMR (400 MHz, CDCl3): δ 1.38 (3H, t, J= 7.2Hz, CH3), 4.37 (2H, q, J= 6.8Hz,
CH2), 7.41-7.56 (3H, m, ArH), 7.87-7.94 (2H, m, ArH), 8.21 (1H, s, =CH).
(E)-ethyl 2-cyano-3-p-tolylacrylate (5b)
1
White solid, mp. 90-92 ℃. H NMR (400 MHz, CDCl3): δ 1.39 (3H, t, J= 7.2Hz, CH3), 2.43 (3H, s, CH3)
4.37 (2H, q, J= 6.8Hz, CH2), 7.30(2H, d, J= 8.0Hz, ArH), 7.90 (2H, d= 8.4Hz, ArH), 8.21 (1H, s, =CH).
(E)-ethyl 2-cyano-3-(4-nitrophenyl)acrylate (5c)
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White solid, mp. 173-174 ℃. H NMR (300 MHz, CDCl3): δ 1.42 (3H, t, J= 7.2Hz, CH3), 4.43 (2H, q, J=
6.9Hz, CH2), 8.14(2H, d, J= 8.7Hz, ArH), 8.31 (1H, s, =CH), 8.36 (2H, d= 9.0Hz, ArH).
(E)-ethyl 3-(4-chlorophenyl)-2-cyanoacrylate (5d)
1
White solid, mp. 89-90 ℃. H NMR (300 MHz, CDCl3): δ 1.40 (3H, t, J= 7.2Hz, CH3), 4.39 (2H, q, J= 7.2