Table 9.
Effect of the properties of metals on the yields of 5a (reaction time: 2 h).
| Metal | χa | Ionic radiusb [pm] | Charge density Z2/r [e2Å−1] | Yield 5a [%] |
| SnCl2 | 1.72 | 102 (CN 2) | 3.92 | – |
| ZrCl4 | 1.22 | 80 (CN 5) | 20.00 | 76 |
| SnCl4 | 1.72 | 76 (CN 5) | 21.05 | 34 |
| TiCl4 | 1.32 | 56 (CN 5) | 28.57 | 56 |
| BCl3 | 2.01 | 25 (CN 4) | 36.00 | – |
| AlCl3 | 1.47 | 53 (CN 4) | 16.98 | 52 |
| GaCl3 | 1.82 | 61 (CN 4) | 14.80 | 93 |
| InCl3 | 1.49 | 76 (CN 4) | 11.84 | 85 |
| LaCl3 | 1.08 | 117 (CN 6) | 7.69 | – |
| CeCl3 | 1.08 | 115 (CN 6) | 7.82 | – |
| Sc(OTf)3 | 1.20 | 89 (CN 6) | 10.11 | – |
a χ: Electronegativity (According to Allred and Rochow). b CN = Coordination number [55].