Substrate scope for the preparation of 4-pyrrolylmethylated products 8a.
| |||||
|---|---|---|---|---|---|
| Entry | Ar | R | t (h) | Yieldb (%) | rrc |
| 1 | Ph | Ph | 36 | 8a, 75 | 7 : 93 |
| 2 | 2-MeC6H4 | Ph | 36 | 8b, 74 | 7 : 93 |
| 3 | 3-MeC6H4 | Ph | 24 | 8c, 66 | 10 : 90 |
| 4 | 4-MeC6H4 | Ph | 96 | 8d, 67 | 18 : 82 |
| 5 | 4-PhC6H4 | Ph | 24 | 8e, 72 | <5 : 95 |
| 6 | 2-FC6H4 | Ph | 24 | 8f, 54 | <5 : 95 |
| 7 | 4-FC6H4 | Ph | 12 | 8g, 72 | <5 : 95 |
| 8 | 4-ClC6H4 | Ph | 12 | 8h, 73 | <5 : 95 |
| 9 | 2-Naphthyl | Ph | 36 | 8i, 69 | 14 : 86 |
| 10d | 2-Furyl | Ph | 36 | 7j+8j, 70 | 20 : 80 |
| 11 | 2-Thienyl | Ph | 36 | 8k, 60 | 26 : 74 |
| 12e | Ph | 2-MeC6H4 | 36 | 8l, 73 | <5 : 95 |
| 13 | Ph | 4-MeC6H4 | 12 | 8m, 62 | 18 : 82 |
| 14e | Ph | 2-ClC6H4 | 36 | 8n, 67 | <5 : 95 |
| 15 | Ph | 2-Furyl | 36 | 7n, 76 | >95 : 5 |
| 16 | Ph | n-Butyl | 48 | 7q, 45 | >95 : 5 |
Unless noted otherwise, reactions were performed with 1,6-enyne 5 (0.2 mmol), imine 3 (0.1 mmol), Pd(allyl)Cp (10 mol%), PPh3 (20 mol%), A3 (20 mol%) and 4 Å MS (40 mg) in degassed dry toluene (1.0 mL) at 70 °C under Ar.
Yield of isolated pure product 8.
rr = 7 : 8, determined by 1H NMR analysis.
Total yield of 7j and 8j, with 20 : 80 rr as inseparable isomers.
With 1 : 1 dr for atropisomers.