Table 6. Reaction of Diene 1 with Different Dienophiles in Various Solventsa.
| entry | DES/IL | dienophile | reaction conditions | yield % | endo/exo ratio | refs |
|---|---|---|---|---|---|---|
| 1 | water | ethyl acrylate | 1 h, 25 °C | 30 | 3.5:1 | (15) |
| 2 | MeOH | methyl acrylate | 30 °C, np | Np | 5.2:1 | (44) |
| 3 | diethyl ether | methyl acrylate | 72 °C, 25 °C | Np | 2.9:1 | (30) |
| 4 | [EAN] (0.20 M) | methyl acrylate | 72 h, 25 °C | 98 | 2.9:1 | (12) |
| 5 | [AlCl3:BPC] (1.04:1) | methyl acrylate | 72 h, 25 °C | 95 | 5.2:1 | (17) |
| 6 | [AlCl3:BPC] (1.5:1) | methyl acrylate | 1.5 h, 25 °C | 80 | 3:1 | (17) |
| 7 | [GlcO(CH2)2N111][Tf2N] (1:1) | methyl methacrylate | 1 h, 25 °C | 92 | 1.9:1 | (42) |
| 8 | [bmim][CS] (1:1) | ethyl acrylate | 20 h, –10 °C | 66 | 6.1:1 | (14) |
| 9 | [bmim][PF6] (1:1) | methyl acrylate | 1 h, 20 °C | 36 | 8.0:1 | (13) |
| 10 | [emim][BF4] (1:1) | methyl acrylate | 2 h, np | 50 | 5.7:1 | (31) |
| 11 | [EtNH3][NO3] (1:1) | methyl acrylate | 72 h, 25 °C | Np | 6.7:1 | (31) |
| 12 | [fructose/DMU] (2.3:1) | methyl acrylate | 8 h, 71 °C | 79 | 2.9:1 | (25) |
| 13 | [DNTPAOAc][LA]rac(1:2) | ethyl acrylate | 72 h, 25 °C | 82 | 8.6:1 |
a
Reaction time and temperature, yield, and endo/exo ratios are indicated. n.p: not provided, [GlcO(CH2)2N111][Tf2N]: N-[2-(d-glucopyranosyl)ethyl]-N,N,N-trimethylammonium bistriflimide. EAN: Ethylammonium-Nitrate; BPC: N-l-butylpyridinium chloride; bmim: 3-buty-l-methylimidazolium; emim: 1-ethyl-3-methylimidazolium; DMU: N,N′-dimethylurea. [LA]: lactic acid; and [DNTPAOAc]: 2,3-diacetoxy-N,N,N-triethylpropan-1-amino acetate.