Syun Satio等研究发现,在零价镍催化下氯代芳烃和芳基硼酸在80℃可高产率地发生偶联反应,零价镍自NiCl2(dppf) (10 mol%)和n-BuLi(40mol%)“一锅”反应来制备,而氯代芳烃可带有各种吸电子或给电子基因. 此方法中镍催化剂成本低,同时选用廉价的氯代芳烃作为反应物,因而有很高的工业应用价值;也有人研究使用NiCl2(PPh3)2来催化烷基取代硼酸盐和溴代物的偶取反应,在室温下以80%的高产率合成了生物活性化合物。
反应机理
反应实例
Representative procedure: A solution of BuLi in hexane (0.4 mmol) wasadded to a solution of NiCl2(dppf) (0.1 mmol) in dioxane (4 ml) at roomtemperature to give a red solution of nickel(0) complex. After being stirred for 10 min, phenylboronicacid (1.1 mmol), K3PO4 (3.0 mmol), a chloroarene (1.0 mmol and an additionaldioxane (2 ml) were added to the flask. The reaction mixture was stirred at 84 ℃ for the period indicated in theTable 2 The product was isolated by chromatography over silica gel.
Tetrahedron Letter: Vol.37, No. l7, pp. 2993-2996, 1996
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