Table 5. Comparison of the Activity of the New Catalytic System Including Bridged-Bis(NHC)PdBr2 (C1) in Cyclocarbonylative Sonogashira Coupling Reactions of 2-Iodophenol and Alkynes with Literature Data.
| refs | catalyst | co-catalyst/ligand/additive | base | time (h) | yield (%) |
|---|---|---|---|---|---|
| (33) | PdCL2 (5 mol %) | (H13C6)3P+C14H29Br– (1.5 g) | Et3N | 24 | 64–95 |
| (31) | PdCL2 (5 mol %) | PPh3 (10 mol %) | Et3N | 24 | 35–95 |
| (35) | Pd(OAc)2 (5 mol %) | DPPF (5 mol %) | piperazine | 24 | 30–95 |
| (32) | Pd2(dba)3 (1.5 mol %) | 1,3,5,7-tetramethyl-2,4,8-trioxa-6-phenyl-6-phosphaadamantane (3 mol %) | DBU | 0.5 MW | 62–95 |
| (40) | Pd(Pph3)4 (3 mol %) | Ac2O (6 mol %) | Et3N | 51–82 | |
| (38) | Pd–NHC–Py (0.5 mol %) | imidazole (0.5 mol %) pyridine (0.5 mol %) | Et2NH | 24 | 25–98 |
| (49) | Pd/C (1 mol %) | Et2NH | 20 | 74–98 | |
| this work | bridged-bis(NHC)PdBr2 (0.5 mol %) | Et2NH | 16 | 53–98 |