Iodine → 2-(Di-t-butylphosphino)-4'-(trifluoromethyl)biphenyl

Participants

Reaction Steps

An oven dried Schlenk tube was evacuated and backfilled with argon and charged with magnesium turnings (90 mg, 3.69 mmol), 2-bromo-4′-(trifluoromethyl)biphenyl (1.01 g, 3.35 mmol), and a crystal of iodine. The tube was purged with argon for 5 minutes, then THF (6 mL) was added through a rubber septum and the reaction mixture was heated to reflux for 1 hour. The reaction mixture was cooled to room temperature and cuprous chloride (365 mg, 3.69 mmol) and chloro-di-t-butylphosphine (0.765 mL, 4.03 mmol) were added. Heating was resumed for 14 hours. The reaction mixture was then cooled to room temperature and diluted with ether (40 mL). The suspension was filtered to isolate the solid. The solid was partitioned between ethyl acetate (60 mL) and 38% ammonium hydroxide (75 mL). The aqueous layer was extracted with ethyl acetate (60 mL). The -combined organic layers were washed with brine (50 mL), dried over anhydrous sodium sulfate, decanted, and concentrated in vacuo. The product was crystallized from MeOH (10 mL) to afford 131 mg (11%) of pale yellow needles. A second crop was isolated by concentrating the mother liquor and recrystallizing the solid from MeOH (20 mL) and water (2 mL) to afford 260 mg (21%) of the product.

Provenance & Evidence