2-(Di-tert-butylphosphino)biphenyl → 9-(4-tert-butylpyridin-2-yl)-2-(3-(4-phenyl-1H-pyrazol-1-yl)phenoxy)-9H-carbazole

Participants

Reaction Conditions

Reaction Steps

2-(3-(4-Phenyl-1H-pyrazol-1-yl)phenoxy)-9H-carbazole 6 (401 mg, 1.0 mmol, 1.0 eq), Pd2(dba)3 (46 mg, 0.05 mmol, 0.05 eq), JohnPhos (30 mg, 0.10 mmol, 0.1 eq) and tBuONa (154 mg, 1.6 mmol, 1.6 eq) were added to a dry pressure Schlenk tube equipped with a magnetic stir bar. The tube was evacuated and back-filled with nitrogen, the evacuation and back-fill procedure was repeated twice. Then dry solvent toluene (4 mL), dioxane (4 mL) and 2-bromo-4-tert-butylpyridine (418 mg, 2.0 mmol, 2.0 eq) were added under a nitrogen atmosphere. The tube was sealed and the mixture was stirred at a temperature of 100-110° C. for 39 hours, and cooled to ambient temperature. The solvent was removed under reduced pressure and the residue was purified through column chromatography on silica gel using hexane and ethyl acetate (20:1-15:1-10:1-5:1) as an eluent to obtain the desired product, 9-(4-tert-butylpyridin-2-yl)-2-(3-(4-phenyl-1H-pyrazol-1-yl)phenoxy)-9H-carbazole Ligand ON6-tBu, as a brown solid (460 mg in 86% yield). 1H NMR (DMSO-d6, 400 MHz): δ 1.24 (s, 9H), 7.04 (dd, J=8.0, 2.6 Hz, 1H), 7.16 (dd, J=8.4, 2.4 Hz, 1H), 7.24 (t, J=7.6 Hz, 1H), 7.32-7.47 (m, 6H), 7.53 (t, J=8.4 Hz, 1H), 7.62 (d, J=1.2 Hz, 1H), 7.66 (t, J=2.0 Hz, 1H), 7.69-7.72 (m, 3H), 7.78 (d, J=8.4 Hz, 1H), 8.19 (s, 1H), 8.24 (d, J=7.6 Hz, 1H), 8.31 (d, J=8.8 Hz, 1H), 8.57 (d, J=5.6 Hz, 1H), 9.05 (s, 1H).

Provenance & Evidence