4-Bromobiphenyl → Biphenyl

Participants

Reaction Conditions

Reaction Steps

To a solution of 4.75 g (12.7 mmol) of N-(2R-(t-Butoxycarbonyl)methyl-4-pentenoyl)-4S-phenylmethyl-2-oxazolidinone, 3.73 g (16.0 mmol) of 4-bromobiphenyl, 0.234 g (0.77 mmol) of tri-o-tolylphosphine, and 2.22 mL (1.62 g, 16.0 mmol) of triethylamine in 10 mL of anhydrous DMF under argon was added 0.086 g (0.385 mmol) of palladium(II) acetate. The solution was heated at 100° C. for 4 h, cooled to room temperature, diluted with ethyl acetate. The precipitate was removed by filtration, and the filtrate was partitioned between 150 mL of 2:1 ethyl acetate:hexane and 50 mL of pH 7 phosphate buffer (0.5 M) containing a little sodium sulfite. The organic layer was washed with 0.2 N aq. sodium bisulfate and brine/pH 7 phosphate buffer, dried over sodium sulfate, and concentrated. The residue was dissolved in 50 mL of ethyl acetate, diluted with 250 mL of isooctane, and seeded with a few crystals of the product. The solid was removed by filtration, and recrystallized from 250 mL of 4:1 isooctane:ethyl acetate to give 4.20 g (63%) of the product, N-(2R-(t-Butoxycarbonyl)methyl-(5-(biphen-4-yl)-4-pentenoyl)-4S-phenylmethyl-2-oxazolidinone, as fine white needles: mp 118-119° C.; 1H NMR (300 MHz, CDCl3) 7.25-7.60 (m, 14H), 6.47 (d, 1H, J=16 Hz), 6.25 (dt, 1H, J=16 and 8 Hz), 4.65-4.70 (m, 1H), 4.34-4.44 (m, 1H), 4.11 (dd, 1H, J=9 and 2 Hz), 4.01 (t, 1H, J=8 Hz), 3.33 (dd, 1H, J=14 and 3 Hz), 2.89 (dd, 1H, J=17 and 11 Hz), 2.76 (dd, 1H, J=14 and 10 Hz), 2.40-2.57 (m, 3H), 1.43 (s, 9H).

Provenance & Evidence