Diethyl Ether → 2-[Bis(1-adamantyl)phosphino]biphenyl

Participants

Reaction Steps

An oven dried Schlenk tube was charged with magnesium turnings (240 mg, 9.89 mmol), 2-bromo-biphenyl (1.55 mL, 7.5 mmol). The tube was evacuated and backfilled with argon two times. To the above mixture THF (15 mL) was added through a rubber septum and the reaction mixture was heated to a mild reflux for 3 hours. The reaction mixture was then temporarily cooled to room temperature for the addition of cuprous chloride (930 mg, 9.45 mmol) followed by a solution of the di-1-adamantylchlorophosphine in 5 mL THF. Heating was resumed for an addtional 3 hours. The reaction mixture was cooled to room temperature, and ether (50 mL) and pentane (50 mL) were added. The resulting suspension was stirred for 10 minutes, during which time a heavy dark-brown precipitate formed. The suspension was filtered and the solid was collected on a fritted funnel. The solid was partitioned between ethyl acetate-ether (100 mL 1:1) and 38% ammonium hydroxide-water (100 mL 1:1). The mixture was vigorously shaken several times over 30 minutes. The aqueos layer washed twice with ether-ethyl acetate (1:1, 100 mL). The combined organic layers were washed with brine (2×50 mL), dried over anhydrous magnesium sulfate, decanted, and concentrated in vacuo. The product was crystallized from toluene/methanol to afford 450 mg (5.8%) product as a white solid.

Provenance & Evidence