Compound B1-1

(t-BuXantphos)Pd(CF3)(CF3CO2)

From: Controllable catalytic difluorocarbene transfer enables access to diversified fluoroalkylated arenes

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Compound data: Crystallographic data

Synthetic procedure: See article for the definitive version of this procedure and for full experimental details.

To a 50 mL round flask bottle with a stir bar were added Pd[P(o-toyl)3]2 (730 mg, 1.0 mmol, 1.0 equiv) and anhydrous THF (20 mL) in glovebox. Subsequently, trifluoroacetic anhydride (210 μL, 1.5 mmol, 1.5 equiv) was added dropwise. After stirring for 30 min at room temperature, the resulting solution was filtered through a pad of Celite. The volatiles were removed under reduced pressure. The residue was dissolved in 50 mL benzene, and the resulting solution was heated to reflux for 1 h. After cooling to room temperature, benzene was evaporated to provide palladium complex B2 (see Supplementary Information). Complex B2 was used for the next step directly. Complex B2 and t-Bu-Xantphos (410 mg, 1.0 mmol, 1.0 equiv) were then dissolved in methyl tert-butyl ether (MTBE). The mixture was stirred for 12 h at 80 oC until the product precipitated. The product was filtered, washed by Et2O, and dried under reduced pressure to afford palladium complex [(t-Bu-Xantphos)PdII(CF3)(CF3CO2)2] (B1-1) as a pale yellow solid (417 mg, 53 % overall yield, 3 steps). Data for complex B1-1: 1H NMR (400 MHz, CDCl3) δ 7.97 – 7.90 (m, 2 H), 7.85 (d, J = 7.4 Hz, 2 H), 7.52 (t, J = 7.8 Hz, 2 H), 1.69 (s, 6 H), 1.48 (d, J = 8.0 Hz, 18 H). 1.46 (d, J =8.0 Hz, 18 H). 13C NMR (101 MHz, CD2Cl2) δ 160.0 (q, J = 31.8 Hz), 155.4 (d, J = 5.6 Hz), 155.3 (d, J = 5.6 Hz), 135.6, 132.56 (d, J = 2.7 Hz), 132.54 (d, J = 2.7 Hz), 132.3, 126.66 (d, J = 3.0 Hz), 126.63 (d, J = 3.0 Hz) 117.0 (d, J = 12.5 Hz), 116.9 (d, J = 12.5 Hz), 39.25 (d, J = 7.0 Hz), 39.18 (d, J = 7.0 Hz), 34.6, 32.7, 30.67 (d, J = 2.0 Hz), 30.65 (d, J = 2.0 Hz). (NOTE: The signals for carbons corresponding to Pd-CF3 and CF3CO2 are not shown in the spectrum). 19F NMR (376 MHz, CDCl3) δ 11.6 (t, J = 29.6 Hz, 3 F), -75.0 (s, 3 F). 31P NMR (162 MHz, CDCl3) δ 58.07 (q, J = 29.6 Hz, 2 P). Sample for the X-ray crystal structure analysis was recrystallized from pentane/DCM.