Sodium Pyridine-2-sulfinate

• Sodium Pyridine-2-sulfinate [O0533]
• 4-Bromotoluene [B0661]
• Palladium(II) Acetate (Purified) [P2161]
• Di-tert-butyl(methyl)phosphonium Tetrafluoroborate [D4731]
• Potassium Carbonate [P1748]
• 1,4-Dioxane

Sodium pyridine-2-sulfinate (0.15 g，0.88 mmol), palladium(II) acetate (6.6 mg, 29 µmol), di-tert-butyl(methyl)phosphonium tetrafluoroborate (15 mg, 58 µmol), 4-bromotoluene (0.10 g, 0.58 mmol), potassium carbonate (0.16 g, 1.2 mmol), 1,4-dioxane (3 mL) were placed in a pressure vessel under nitrogen atmosphere at room temperature. The reaction mixture was stirred for 4 days at 120 °C, then palladium(II) acetate (6.6 mg, 29 µmol) and di-tert-butyl(methyl)phosphonium tetrafluoroborate (15 mg, 58 µmol) was added. The reaction mixture was stirred for another 4 days at 120 °C, then diluted with ethyl acetate and washed with water. The organic layer was dried by sodium sulfate, then concentrated under reduced pressure. The resulting crude product was purified by column chromatography (hexane:ethyl acetate = 5:1 on silica gel) to give 1 as a yellow oil (29 mg, 29% yield).

The reaction mixtures were monitored by ¹H NMR.

2-(p-Tolyl)pyridine (1)

¹H NMR (400 MHz, CDCl₃); δ 8.68 (d, 1H, J = 5.0 Hz), 7.89 (d, 2H, J = 8.3 Hz), 7.78-7.68 (m, 2H), 7.28 (d, 2H, J = 7.8 Hz), 7.23-7.18 (m, 1H), 2.41 (s, 3H).

¹³C NMR (101 MHz, CDCl₃); δ 157.8, 149.7, 139.1, 136.8, 136.7, 129.6, 126.9, 121.9, 120.4, 21.4. (2C are overlapped at aromatic area)

• Catalyst Selection Facilitates the Use of Heterocyclic Sulfinates as　General Nucleophilic　Coupling Partners in Palladium-Catalyzed　Coupling Reactions
• T. Markovic, B. N. Rocke, D. C. Blakemore, V. Mascitti, M. C. Willis, Org. Lett. 2017, 19, 6033.