Syun Satio等研究發(fā)現(xiàn),在零價鎳催化下氯代芳烴和芳基硼酸在80℃可高產(chǎn)率地發(fā)生偶聯(lián)反應(yīng),零價鎳自NiCl2(dppf) (10 mol%)和n-BuLi(40mol%)“一鍋”反應(yīng)來制備,而氯代芳烴可帶有各種吸電子或給電子基因. 此方法中鎳催化劑成本低,同時選用廉價的氯代芳烴作為反應(yīng)物,因而有很高的工業(yè)應(yīng)用價值;也有人研究使用NiCl2(PPh3)2來催化烷基取代硼酸鹽和溴代物的偶取反應(yīng),在室溫下以80%的高產(chǎn)率合成了生物活性化合物。
反應(yīng)機(jī)理
反應(yīng)實例
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
本文內(nèi)容來源于網(wǎng)絡(luò),版權(quán)歸原作者所有。