Table 3.
Activity, selectivity, and kinetic parameters for the cyclopropanation of styrene with α-diazoester derivatives catalyzed by Mb(H64V,V68A) and variants thereof.a
| Entry | Catalyst | Diazo | Yieldb | TON | % de | % ee |
kcatc (min−1) |
KMc (mM) |
|---|---|---|---|---|---|---|---|---|
| 1 | Mb(H64V,V68A) | 2a | 99% | >500 | 99.9 | 99.9 | 585 | 21.1 |
| 2 | Mb(H64V,V68A) | 2b | 84% | 420 | 93 | 83 | 103 | 7.3 |
| 3 | Mb(H64V,V68A) | 2c | 66% | 330 | 93 | 59 | 45 | 3.0 |
| 4 | Mb(H64V,V68A) | 2d | 99% | >500 | 83 | 92 | 295 | 3.2 |
| 5 | Mb(H64V,V68A) | 2e | 99% | >500 | 96 | 96 | 320 | 6.4 |
| 6 | Mb(H64V,V68A) | 2f | 41% | 205 | 99 | 84 | 62 | 8.1 |
| 7 | Mb(H64V,V68G) | 2a | 99% | >500 | 77 | 96 | n.d. | n.d. |
| 8 | Mb(H64V,V68G) | 2b | 77% | 385 | 69 | 76 | n.d. | n.d. |
| 9 | Mb(H64V,V68G) | 2c | 99% | >500 | 95 | 2 | n.d. | n.d. |
| 10 | Mb(L29A,H64V,V68A) | 2a | 99% | >500 | 96 | 84 | n.d. | n.d. |
a
Reaction conditions: 10 mM styrene (1), 20 mM diazo reagent (2a-2f), 10 mM Na2S2O4, 20 μM purified Mb variant in phosphate buffer (50 mM, pH 7.0), under anaerobic conditions, room temperature, 16 hours.
b
GC yield.
c
Apparent kinetic parameters for the carbene donor at sub-saturating styrene concentration (20 mM) under aerobic conditions.