Table 2.
entry | precatalyst (mol %) | ligand (mol %) | additive | 2 (%)a | 3 (%)a | 4 (%)a |
---|---|---|---|---|---|---|
1 | none | none | none | 100 | 0 | 0 |
2 | Pd2dba3 (5 mol %) | Cy3P (20 mol %) | none | 53 | 15 | 32 |
3 | Pd2dba3 (5 mol %) | none | none | 0 | 35 | 65 |
4 | Pd2dba3 (5 mol %) | Ph3P (20 mol %) | none | 65 | 10 | 25 |
5 | Pd2dba3 (5 mol %) | SPhos (10 mol %) | none | 0 | 56 | 44 |
6 | Pd2dba3 (5 mol %) | tBuPPh2 (20 mol %) | none | 19 | 19 | 62 |
7 | Pd2dba3 (5 mol %) | L1 (20 mol %) | none | 2 | 16 | 82 |
8 | Pd2dba3 (2.5 mol %) | L1 (10 mol %) | none | 0 | 18 | 82 |
9b | Pd2dba3 (2.5 mol %) | L1 (10 mol %) | LiOTfc | 0 | 0 | >99 |
10b | (L1)2PdCl2 (2.5 mol %) | none | LiOTfc | 0 | 0 | >99 |
Yield determined by NMR.
90 °C.
1.5 equiv.