烯基卤代物与金属试剂的偶联

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    过渡金属催化的烯基化合物偶联反应,目前也已经得到了长足的发展,如Suzuki反应,Stille反应, Negishi反应,Heck 反应,RCM反应都是构建烯烃的常用反应。此类反应可以分为3类:

1)烯基卤代物(包含磺酸酯)与金属试剂的偶联(Suzuki反应等);

2)烯基卤代物(包含磺酸酯)与烯基化合物的偶联(Heck反应);

3)烯基化合物与烯基化合物的偶联(RCM反应)。

烯基卤代物与金属试剂的偶联

实例一

A mixture of A (418 mg, 2.26 mmol),2,4,6-trivinylcyclotriboroxane-pyridine complex (528 mg, 2.26 mmol), K2CO3 (316 mg, 2.26 mmol), and Pd(PPh3)4 (128 mg, 0.113 mmol, 5mol %) were placed under argon. A degassed mixture of DME and water was added, and the reaction mixture was heated at reflux temperature (the oil-bath temperature was set to 100 °C) for 15 h. The reaction mixture was extracted with CH2Cl2 and the organic fraction dried over Na2SO4. Insoluble materials were removed by filtration, and the solvent was removed under vacuum. The crude product was purified by column chromatography (50 g SiO2,cyclohexane:ethyl acetate = 20:1). Yield: 278 mg (93%).

Reference: Organometallics,2004, 23(15), 3622-3626.


实例二

To a solution of 2-bromoaniline(182 mg, 1.06 mmol) and Pd(PPh3)4 (108 mg, 10 mol %) in 5 mL of toluene was added to tributylvinyltin (350 μL, 1.20 mmol). The mixture was stirred at 100°C under an argon atmosphere for 6 h and extracted with ethyl acetate. The extract was washed with water and brine, dried over anhydrous magnesium sulfate, and concentrated. The residue was purified by silica gelcolum chromatography (eluent: n-hexane/ethyl acetate = 9:1 to 5:1, v/v, silicagel/KF = 10:1, w/w) to afford of the desired compound (51.7 mg, 41% yield) as yellow oil.

Reference:  Journal of Medicinal Chemistry, 55(17),  7360-7377; 2012.


实例三

To a solution of compound A1 (3.9 g, 13 mmol) in DME (60mL) was added to boronic acid A2 (2.6 g, 17 mmol), LiCl (1.6 g, 38 mmol), Pd(PPh3)4 (0.45 g, 0.39 mmol), 2.0 M Na2CO3 (19 mL) solution. The mixture was degassed and heated to 80°C for 2 h. The mixture was cooled to room temperature and diluted with water (50 mL). The mixture were extracted with EtOAc (3× 50 mL) and the combined extracts were washed with brine, dried over anhydrous MgSO4 and concentrated in vacuo. The residue was purified by chromatography on silica gel (petroleum ether/ethyl acetate = 15:1) to afford P (2.9 g, 86% yield) as an oil.

Reference: Organic Letters, 15(14), 3722-3725; 2013.


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