Table 1.
Optimization of reaction conditionsa.
| Entry | B2cat2 | PC (mol%) | Light | Additive | Yielda,b(%) |
|---|---|---|---|---|---|
| 1 | 3.0 | Ir(p-CF3ppy)3 (2 mol%) | 456 nm | Et3N (2.0) | 45 |
| 2 | 3.0 | Ir(p-CF3ppy)3 (2 mol%) | 456 nm | DABCO (2.0) | 15 |
| 3 | 3.0 | Ir(p-CF3ppy)3 (2 mol%) | 456 nm | DIPEA (2.0) | 47 |
| 4 | 3.0 | Ir(p-CF3ppy)3 (2 mol%) | 456 nm | none | trace |
| 5c | 3.0 | Ir(p-CF3ppy)3 (2 mol%) | 456 nm | DIPEA (2.0) | 49 |
| 6 | 3.0 | Ir(ppy)3 (2 mol%) | 456 nm | DIPEA (2.0) | 30 |
| 7 | 3.0 | [Ru(bpy)3]Cl2 (2 mol%) | 456 nm | DIPEA (2.0) | trace |
| 8 | 3.0 | 4CzIPN (2 mol%) | 456 nm | DIPEA (2.0) | trace |
| 9 | 3.0 | Eosin Y (2 mol%) | 456 nm | DIPEA (2.0) | 47 |
| 10 | 3.0 | Eosin Y (2 mol%) | 467 nm | DIPEA (2.0) | 73 |
| 11 | 3.0 | Eosin Y (5 mol%) | 467 nm | DIPEA (2.0) | 77 |
| 12 | 2.5 | Eosin Y (5 mol%) | 467 nm | DIPEA (2.0) | 81 (73) |
| 13 | 4.0 | Eosin Y (5 mol%) | 467 nm | DIPEA (2.0) | 40 |
| 14 | 2.5 | Eosin Y (5 mol%) | 467 nm | DIPEA (1.5) | 54 |
| 15 | 2.5 | None | 467 nm | DIPEA (2.0) | trace |
| 16 | 2.5 | Eosin Y (5 mol%) | none | DIPEA (2.0) | trace |
| 17 | 2.5 | Eosin Y (5 mol%) | 467 nm | None | trace |
| 18d | 2.5 | Eosin Y (5 mol%) | none | DIPEA (2.0) | trace |
| 19e | 2.5 | Eosin Y (5 mol%) | 467 nm | DIPEA (2.0) | trace |
| 20f | 2.5 | Eosin Y (5 mol%) | 467 nm | DIPEA (2.0) | 76 |
aReactions run on 0.2 mmol scale, using Kessil 40 W blue LED as light source.
bGC-fid yields are measured by using decane as an internal standard. The yield in bracket is isolated yield.
cThe reaction time is 30 h.
d50 °C for 12 h, in the dark.
eTurned off the light after 30 min.
fThe reaction was set up in air.