2-(Di-tert-butylphosphino)biphenyl

Used Chemicals

• Morpholine [M0465]
• 4-Chlorotoluene [C0297]
• Palladium(II) Acetate (Purified) [P2161]
• JohnPhos [D3387]
• Sodium tert-Butoxide [S0450]
• Toluene

Procedure

To a solution of sodium tert-butoxide (0.54 g, 5.6 mmol), palladium(II) acetate (4.5 mg, 0.020 mmol), and JohnPhos (0.012 g, 0.040 mmol) in toluene (8 mL) 4-chlorotoluene (0.51 g, 4.0 mmol) and morpholine (0.42 g, 4.8 mmol) were successively added at room temperature. The mixture was stirred under nitrogen atmosphere at room temperature for 1.5 days, then under reflux condition for 0.5 days. Diethyl ether (20 mL) was added to the reaction mixture and filtered through celite. Solvent was removed and the residue was purified by column chromatography (1:4 ethyl acetate / hexane on SiO₂), giving 4-(p-tolyl)morpholine as a pale brown solid (0.45 g, 63% yield).

Experimenter's Comments

The reaction mixture was monitored by ¹H NMR.

Analytical Data (4-(p-Tolyl)morpholine)

¹H NMR (400 MHz, CDCl₃); δ 7.10 (d, J = 8.2 Hz, 2H), 6.85 (d, J = 8.2 Hz, 2H), 3.87 (t, J = 4.6 Hz, 4H), 3.12 (t, J = 4.8 Hz, 4H), 2.28 (s, 3H).

¹³C NMR (101 MHz, CDCl₃); δ 129.9 (4 C), 116.2 (2 C), 67.1 (2 C), 50.1 (2 C), 20.6.

Lead Reference

• A Highly Active Catalyst for the Room-Temperature Amination and Suzuki Coupling of Aryl Chlorides
  • J. P. Wolfe, S. L. Buchwald, Angew. Chem. Int. Ed. 1999, 38, 2413.

Other References

• Simple, Efficient Catalyst System for the Palladium-Catalyzed Amination of Aryl Chlorides, Bromides, and Triflates
  • J. P. Wolfe, H. Tomori, J. P. Sadighi, J. Yin, S. L. Buchwald, J. Org. Chem. 2000, 65, 1158.

Reference

• Designer HF-Based Fluorination Reagent: Highly Regioselective Synthesis of Fluoroalkenes and gem-Difluoromethylene Compounds from Alkynes
  • O. E. Okoromoba, J. Han, G. B. Hammond, B. Xu, J. Am. Chem. Soc. 2014, 136, 14381.

Reference

• S. E. Denmark, C. R. Butler, Org. Lett. 2006, 8, 63.