Table 6. Effect of the Catalyst Loading on the Reaction Efficiency [Yields, Isomeric Content (α/β Ratio) and TONs]a,b.
| yields,
isomeric ratio, and TON under selected conditions |
|||
|---|---|---|---|
| entry | catalyst loading, mol % | 80 °C/6 h | 100 °C/4 h |
| 1–2 | 1 | 83 (17/83) 83 | 82 (17/83) 82 |
| 3–4 | 0.1 | 90 (19/81) 900 | 85 (48/52) 850 |
| 5–6 | 0.01 | 85 (68/32) 8500 | 77 (68/32) 7700 |
| 7–8 | 0.001 | 9 (64/36) 9000 | 7 (62/38) 7000 |
| 9–10 | 0.0001 | <5 | <5 |
PhC≡CH (5.0 × 10–4 mol, 1 equiv), Et3SiH (5.0 × 10–4 mol, 1 equiv), catalyst 18; toluene (0.5 mL).
Yields of products were determined by 1H NMR spectroscopy using 1,2-dimethoxyethane as the standard, whereas the isomeric content was determined on the basis of the alkene coupling constants.