[1,1'-Bis(di-tert-butylphosphino)ferrocene]palladium(II) Dichloride

Used Chemicals

• 4-Chloroanisole [C0122]
• Phenylboronic Acid [B0857]
• [1,1'-Bis(di-tert-butylphosphino)ferrocene]palladium(II) Dichloride [B3160]
• Potassium Carbonate [P1748]
• DMF

Procedure

To a two-necked flask was charged with potassium carbonate (832 mg, 6.02 mmol, 2.01 equiv.), phenylboronic acid (384 mg, 3.15 mmol, 1.05 equiv.), [1,1'-bis(di-tert-butylphosphino)ferrocene]palladium(II) dichloride (20 mg, 0.031 mmol, 1.0 mol%), 4-chloroanisole (0.362 mL, 3.00 mmol, 1.0 equiv.) and degassed DMF (15 mL) under argon atmosphere. The resulting mixture was stirred at 120 °C for 15 h. The reaction mixture was cooled to room temperature and diluted with ethyl acetate (30 mL) and washed with 1 mol/L HCl solution (30 mL). The organic layer was separate and the aqueous layer was extracted with ethyl acetate (15 mL). The combined organic layers were washed with brine (15 mL), dried over Na₂SO₄ and filtered. The solvent was removed under reduced pressure. The residue was purified by column chromatography (hexane : ethyl acetate, 100 : 0 → 98 : 2) to obtain 1 as a white solid (0.32 g, 58%).

Experimenter's Comments

The reaction mixture was monitored by TLC (hexane, Rf = 0.30).

Analytical Data（Compound 1）

¹H NMR (400 MHz, CDCl₃); δ 7.53–7.57 (m, 4H), 7.42 (t, J = 7.6 Hz, 2H), 7.31 (t, J = 6.8 Hz, 1H), 6.98 (d, J = 8.4 Hz, 2H).

¹³C NMR (101 MHz, CDCl₃); δ 159.2, 140.9, 133.8, 128.8, 128.2, 126.8, 126.7, 114.2, 55.4.

Lead Reference

• Cp₂Fe(PR₂)₂PdCl₂ (R = i-Pr, t-Bu) Complexes as Air-Stable Catalysts for Challenging Suzuki Coupling Reactions
  • T. J. Colacot, H. A. Shea, Org. Lett. 2004, 6, 3731.

References

• Cp₂Fe(PR₂)₂PdCl₂ (R = i-Pr, t-Bu) Complexes as Air-Stable Catalysts for Challenging Suzuki Coupling Reactions
  • T. J. Colacot, H. A. Shea, Org. Lett. 2004, 6, 3731.
• A Fluorescence-Based Assay for High-Throughput Screening of Coupling Reactions. Application to Heck Chemistry
  • K. H. Shaughnessy, P. Kim, J. F. Hartwig, J. Am. Chem. Soc. 1999, 121, 2123.
• Sterically Hindered Chelating Alkyl Phosphines Provide Large Rate Accelerations in Palladium-Catalyzed Amination of Aryl Iodides, Bromides, and Chlorides, and the First Amination of Aryl Tosylates
  • B. C. Hamann, J. F. Hartwig, J. Am. Chem. Soc. 1998, 120, 7369.
• Simple, Highly Active Palladium Catalysts for Ketone and Malonate Arylation:  Dissecting the Importance of Chelation and Steric Hindrance
  • M. Kawatsura, J. F. Hartwig, J. Am. Chem. Soc. 1999, 121, 1473.