实验室某些钯催化剂的制备方法

钯催化剂在有机合成中的应用十分广泛，很多类型的反应都需要钯催化剂的参与才能顺利进行。在探索路线时，我们经常会用到许多类型的钯复合物来筛选反应条件。下面将分享一些实验室制备不同钯复合物的方法，该方法操作简单，得到的钯催化剂完全可以满足实验需求。

1:Pd(allyl)(RuPhos)Cl

The general procedure was followed using 503mg (1.43mmol) of [(allyl)PdCl]₂, 1.29g (2.77mmol)of RuPhos, and 2mL of anhydrous THF with a stir time of 0.5h. The product was precipitated by the addition of 10mL of pentane with cooling in an ice bath (0°C)to give 1.52g (2.34mmol, 85%) of the title compound as a yellow solid.

2: Pd(crotyl)(RuPhos)Cl

The general procedure was followed using 1.02 g (5.08 mmol) of [(crotyl)PdCl]₂, 2.37g (10.2mmol) of RuPhos, and 2.5mL of anhydrous THF with a stir time of 2h. The product was precipitated by the addition of 10 mL of pentane to give 2.93 g(4.42 mmol,87%) of the title compound as a light yellow solid.

3:Pd(cinnamyl)(RuPhos)Cl

The general procedure was followed using 1.00 g (1.93 mmol) of [(cinnamyl)PdCl]₂, 1.80 g (3.86mmol) of RuPhos, and 4 mL of anhydrous THF with a stir time of 2h. The product was precipitated by the addition of 24 mL of pentane and was triturated for 1h to give 2.13 g (2.94 mmol, 76%) of the title compound as a yellow solid.

4:Pd(allyl)(SPhos)Cl

The general procedure was followed using 4.46 g (12.2 mmol) of [(allyl)PdCl]₂, 10.0 g (24.4mmol) of SPhos, and 30 mL of anhydrous THF with a stir time of 30 min. The product was precipitated by the addition of 30 mL of pentane to give 14.1 g(23.8 mmol, 98%) of the title compound as a white solid.

5:Pd(crotyl)(SPhos)Cl

The general procedure was followed using 501 mg (1.27 mmol) of [(crotyl)PdCl]₂, 1.05 g (2.56mmol) of SPhos, and 5 mL of anhydrous THF with a stir time of 6h (reaction timenot optimized). The product was precipitated by the addition of 10 mL ofpentane to give 1.28 g (2.11 mmol, 82%) of the title compound as a light yellow solid.

6:Pd(cinnamyl)(SPhos)Cl

The general procedure was followed using 1.00 g (1.93 mmol) of [(cinnamyl)PdCl]₂, 1.59 g (3.86mmol) of SPhos, and 4.3 mL of anhydrous toluene with a stir time of 1h. The product was precipitated by the addition of 10 mL of pentane to give 2.56 g(3.82 mmol, 99%) of the title compound as a bright yellow solid.

7:Pd(allyl)(XPhos)Cl

The general procedure was followed using 858 mg (2.36 mmol) of [(allyl)PdCl]₂, 2.26 g (4.74mmol) of XPhos, and 5 mL of anhydrous THF with a stir time of 3h. The product was precipitated by the addition of 10 mL of pentane to give 3.04 g (4.62 mmol,97%) of the title compound as a light yellow solid. Product contains ~5 mol %of THF.

8:Pd(crotyl)(XPhos)Cl

The general procedure was followed using 1.00 g (2.54 mmol) of [(crotyl)PdCl]₂, 2.42 g (5.08mmol) of XPhos, and 30 mL of anhydrous toluene with a stir time of 3h. 60 mL of pentane was added and the mixture was concentrated in vacuo. The residue was dissolved in 5 mL of toluene and precipitated by the addition of 20 mL of pentane to give 3.11 g (4.61 mmol, 91%) of the title compound as an off-white solid.

9:Pd(cinnamyl)(XPhos)Cl

The general procedure was followed using 1.00 g (1.93 mmol) of [(cinnamyl)PdCl]₂, 1.84 g (3.86mmol) of XPhos, and 5 mL of anhydrous toluene with a stir time of 1h. The product was precipitated by the addition of 10 mL of pentane to give 2.27g(3.09 mmol,80%) of the title compound as a bright yellow solid. Product contains trace residual toluene.

10: Pd(allyl)(BrettPhos)Cl

The general procedure was followed using 502 mg (1.38 mmol) of [(allyl)PdCl]₂, 1.48 g (2.76mmol) of BrettPhos, and 6 mL of anhydrous THF with a stir time of 1.5h. The product was precipitated by the addition of 6 mL of pentane to give 1.81 g(2.52 mmol, 91%) of the title compound as an off-white solid.

11:Pd(allyl)(JohnPhos)Cl

The general procedure was followed using 1.00 g (2.75 mmol) of [(allyl)PdCl]₂, 1.64 g (5.50mmol) of JohnPhos, and 13 mL of anhydrous toluene with a stir time of 1.25h.The product was precipitated by the addition of 26.5 mL of pentane to give 2.46g (5.11 mmol, 93%) of the title compound as a yellow solid.

12:Pd(crotyl)(JohnPhos)Cl

The general procedure was followed using 1.00 g (2.54 mmol) of [(crotyl)PdCl]₂, 1.52 g (5.08mmol) of JohnPhos, and 12.5 mL of anhydrous toluene with a stir time of 1.25h.The product was precipitated by the addition of 25 mL of pentane to give 2.40 g(4.84 mmol, 95%) of the title compound as a yellow solid.

13:Pd(allyl)(CyBippyPhos)Cl

A dry 20 mL scintillation vialwas charged with 245 mg (0.67 mmol) of [(allyl)PdCl]₂ and transferred into a nitrogen-filled glove box. The vial was then charged with 750 mg (1.34 mmol) of CyBippyPhos. 4 mL of toluene was added and the mixturewas stirred at rt for 30 min. During the stir time, the mixture became thickand stirring was difficult. An additional 4 mL of toluene was added to allow stirring to continue. The product was fully precipitated by the addition of 8mL of hexanes. The solid was collected by vacuum filtration in air and washed with 3 x 10 mL of hexanes. The solid was dried in vacuo to give 913 mg (1.23mmol, 92%) of the title compound as an offwhite solid. The product contains< 2 wt % of residual toluene.

14: Pd(crotyl)(CyBippyPhos)Cl

A dry Schlenk flask was charged with 264 mg (0.67 mmol) of [(crotyl)PdCl]₂ and transferred into a nitrogen-filled glove box. The flask was then charged with 750 mg (1.34mmol) of CyBippyPhos. 8 mL of toluene was added and the mixture was stirred at rt for 1h. The product was precipitated by the addition of 20 mL of pentane with cooling in an ice bath. The solid was collected by vacuum filtration inair, washed with 3 x 10 mL of hexanes, and dried in vacuo to give 904 mg (1.10mmol, 83%) of the title compound as an off-white solid. The product is a 2/3toluene adduct, which was broken by the dissolution in CH2Cl2 and evaporating the solvent under reduced pressure at 60 °C.

后面这十几种钯催化剂的制备用的是同一种方法，具体操作过程如下:

A dry Schlenk flask equipped with a Teflon-coated magnetic stir bar was charged with [(R-allyl)PdCl]₂(0.50 mmol, 0.50 eq) ,followed by AgOTf (257 mg, 1.00 mmol, 1.00 eq). The flask was fitted with a rubber septum evacuated and backfilled with nitrogen. This evacuation/nitrogen backfill cycle was repeated two additional times. Solvent(10 mL THF or 2-MeTHF) was added and the reaction mixture was stirred at rt for 30 min while protected from light. A second dry Schlenk flask was equipped with a magnetic stir bar, fitted with a Schlenk frit, and charged with the appropriate ligand (1.00 mmol, 1.00 eq). The flask was fitted with a rubber septum and it was evacuated and backfilled with nitrogen. This evacuation/nitrogen backfill cycle was repeated two additional times. The solution from the first Schlenk flask was transferred via cannula through the Schlenk frit (to remove AgCl) and into the second Schlenk flask containing the ligand, rinsing with 5 mL of additional solvent (THF or 2-MeTHF). This mixturewas stirred at rt for 2h. 30 mL of hexanes was then added to fully precipitatethe product. The solid materials were then collected by suction filtration,washed with additional pentane (or hexanes), and dried in vacuo.

通用方法制备的钯催化剂如下表所示

参考文献:DOI: 10.1021/acs.joc.5b0100