Table 1.
Enantioselective cyclopropanation of 1 with EDA under the catalysis of iron porphyrins in the presence and absence of st‐DNA.[a]
| Entry | Porphyrin | st‐DNA [mm] | Yield [%][b] | TTN[c] | ee [%][b] |
|---|---|---|---|---|---|
| 1 | P1 | – | ≤3 | – | – |
| 2 | P1 | 6 | ≤3 | – | – |
| 3 | P2 | – | ≤3 | – | – |
| 4 | P2 | 6 | ≤3 | – | – |
| 5 | P3 | – | ≤3 | – | – |
| 6 | P3 | 6 | 14±2 | 9 | 42 |
| 7[d] | P3 | 6 | 16±4 | 22 | 40 |
| 8[e] | P3 | – | ≤3 | – | – |
| 9 | P3 | 3 | 22±1 | 14 | 33 |
| 10 | P3 | 1.5 | 25±0 | 17 | 24 |
| 11 | P4 | – | 33±3 | 22 | – |
| 12 | P4 | 6 | 15±0.5 | 10 | 23 |
| 13 | P5 | – | 26±0 | 17 | – |
| 14 | P5 | 6 | 11±1 | 7 | 5 |
[a] The experiments were carried out with 1 (5 mm), 2 (50 mm), st‐DNA (6 mm in base pairs), and the FeIII porphyrin (75 μm) in 20 mm MOPS buffer (pH 6.5) containing acetonitrile (3 % v/v) for 5 min at 5 °C, unless otherwise specified. Yields and ee values are based on the areas of HPLC and GC peaks as compared to those of 2‐methyl anisole as an internal standard. All data were averaged over two or more experiments. Errors reported are standard deviations. [b] The yield and ee value (reproducibility: ±3 % ee) of the trans isomer are given. The diastereomeric ratio of the product ranged from 88:12 to 95:5. [c] TTN=total turnover number. [d] Metalloporphyrin concentration: 37.5 μm. [e] Metalloporphyrin concentration: 7 μm.