1-(4-Iodophenyl)ethan-1-one → 4-Acetylbiphenyl

Participants

Reaction Conditions

Reaction Steps

To a solution of 0.101 g (0.410 mmol) of 4′-iodoacetophenone and 1.113 g (2.062 mmol) of TBAT in 10 mL of DMF was added 12 mg (0.033 mmol) of allyl palladium chloride dimer. The reaction mixture was degassed to remove oxygen via one freeze-pump-thaw cycle. The red-brown mixture was heated at 95° C. for 5 h. The resulting brown mixture was quenched by the addition of 50 mnL of H2O; the aqueous layer was then extracted with 4×50 mL of Et2O, and the combined organic layers were dried over MgSO4 and concentrated in vacuo. Purification of the residue by flash chromatography (25 mm, 17 cm, 0-10% EtOAc/hexane) gave 70 mg (86%) of 4-acetylbiphenyl as a yellow solid and 7 mg 14%) of 4,4′-diacetylbiphenyl, the homocoupled product. Recrystallization from absolute EtOH yielded pale yellow needles: TLC Rf=0.29 (10% EtOAc/hexane); mp 119-119.5° C. (lit. mp 119-120° C. (EtOH) Echavarren, A. M. and Stille, J. K., J. Am. Chem. Soc. 109:5478-5486 (1987)); IR (CCl4) 3081 (w), 3038 (w), 3000 (w), 2931 (m), 2850 (w), 1691 (m), 1569 (s), 1538 (s); 1H NMR δ2.63 (s, 3H), 7.88 (t, J=7.3, 1H), 7.46 (t, J=7.4, 2H), 7.61 (d, J=7.2, 2H), 7.67 (A of AB quartet, JAB=8.4, 2H), 8.02 (B of AB quartet, JAB=8.4, 2H); 13C NMR δ26.6, 127.2, 128.2, 128.9, 135.9, 139.9, 145.8, 197.7; LRMS (EI) 197 ((M+1), 10), 196 ((M+), 59), 181 (100), 158 (35), 152 (41); HRMS (EI) calcd for C14H12O 196.0888 (M+); found 196.0883. The IR and 1H NMR are identical to the spectral reported by Echavarren and Stille.

Provenance & Evidence