Table 4.
Inhibition experiments with spin trapping agents in styrene cyclopropanation reaction catalyzed by Mb(H64V,V68A) (1) or Mb(H64V,V68A,H93NMH)[Fe(DADP)] (3).a
| Entry | Catalyst | Styrene | Inhibitor | Yield | % de | % ee |
|---|---|---|---|---|---|---|
| 1 | 1 | Yes | None | >99% | 99 | >99 |
| 2 | 1 | Yes | DMPO | 89% | 99 | >99 |
| 3 | 1 | Yes | TEMPOL | 90% | >99 | 99 |
| 4 | 1 | No | None | 95%b | - | - |
| 5 | 1 | No | DMPO | 80%b | - | - |
| 6 | 3 | Yes | None | >99% | >99 | >99 |
| 7 | 3 | Yes | DMPO | 42% | >99 | 99 |
| 8 | 3 | Yes | TEMPOL | 40% | >99 | 99 |
| 9 | 3 | No | None | 88%b | - | - |
| 10 | 3 | No | DMPO | 8%b | - | - |
a
Reaction conditions: 10 mM styrene, 20 mM EDA, 100 mM DMPO (or TEMPOL), 20 μM Mb variant, 10 mM sodium dithionite in 50 mM potassium phosphate buffer (pH 7) containing 10% DMF, r.t., 16 hours. Yield, diastereomeric and enantiomeric excess were determined by chiral GC-FID analysis.
b
Yield of diethyl fumarate and maleate determined by chiral GC-FID analysis.