Table 2 Optimization of the asymmetric hydroformylation of 1a
From: Silicon-oriented regio- and enantioselective rhodium-catalyzed hydroformylation
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|---|---|---|---|---|---|---|---|---|
Entry | Solvent | x | T (°C) | CO/H2 (bar) | Conv. (%) | Yield (%) | ee (%) | |
2a+3a | 4a | |||||||
1 | Toluene | 1.0 | 70 | 10/10 | 98 | 96 | 2 | 92 |
2 | THF | 1.0 | 70 | 10/10 | >99 | 35 | 65 | – |
3 | CH2Cl2 | 1.0 | 70 | 10/10 | 89 | 80 | 9 | 93 |
4 | EtOAc | 1.0 | 70 | 10/10 | >99 | 95 | 5 | 91 |
5 | DCE | 1.0 | 70 | 10/10 | >99 | 96 | 4 | 90 |
6a | Toluene | 0.6 | 70 | 10/10 | >99 | 25 | 75 | – |
7 | Toluene | 1.5 | 70 | 10/10 | 98 | 90 | 8 | 94 |
8 | Toluene | 1.5 | 70 | 5/5 | >99 | 99 | 1 | 94 |
9 | Toluene | 1.5 | 70 | 2/2 | >99 | 99 | 1 | 94 |
10 | Toluene | 1.5 | 70 | 20/20 | 99 | 91 | 8 | 94 |
11 | Toluene | 1.5 | 60 | 5/5 | 93 | 82 | 11 | 96 |
12 | Toluene | 1.5 | 80 | 5/5 | >99 | 85 | 15 | 91 |
