Table 1 Optimization of reaction conditionsa.
From: Mechanistic insights into photochemical nickel-catalyzed cross-couplings enabled by energy transfer
| ||
|---|---|---|
Entry | Change in standard reaction conditions | Yield (1, %)b |
1 | NiCl2.glyme (5 mol%), 4,4'-dtbbpy (6 mol%) | 36 |
2 | None | 54 |
3 | Ni(cod)2 (5 mol%), 4,4'-dOMe-bpy (5.5 mol%) | 77 |
4 | Ni(cod)2 (10 mol%), 4,4'-dOMe-bpy (11 mol%) | 75 |
5 | H2O (10 equiv.) as additive | 73 |
6 | 1 mol% Ir[dF(CF3)ppy]2(dtbbpy)PF6, Ni(cod)2 (5 mol%) | 74 |
7 | Ir[ppy]2(dtbbpy)PF6 instead of PS1 | 0 |
8 | Ru(bpz)3·2PF6 instead of PS1 | 0 |
9 | (9-MesAcr)ClO4 instead of PS1 | 0 |
10 | 4-CzIPN (2 mol%) instead of PS1, Ni(cod)2 (5 mol%) | 30 |
11 | without [Ir] photosensitizer | 0 |
12 | without [Ni] catalyst | 0 |
13 | without Light source | 0 |
14 | without base | trace |
15 | without fan cooling (around 50 °C) | 51 |
16 | (3-chloropropyl)benzene instead of alkyl bromide | 0 |
