In the presence of Pd(PPh3)4, NaBr and KF·2H2O the cross-coupling reaction of heteroaryl triflates with trans-cyclopropylboronic acids proceeds readily to give pure trans-cyclopropyl heteroarenes in moderate to good yields. The X-ray crystallography of compound 3g and 1H-NMR spectra of all products show that the configuration of the cyclopropyl group was retained during the reaction. Under the same reaction conditions, highly
optically active cyclopropyl-substituted heteroarenes (up to 94% ee) were obtained by
cross-coupling of heteroary/triflates with enantiomerically enriched cyclopropylboronic acids.
在Pd(PPh3)4、NaBr和KF·2H2O的存在下,异芳基
三氟甲烷磷酸酯与反式环丙基
硼酸的交叉偶联反应顺利进行,得到纯净的反式环丙基异
芳烃,产率为中等到优良。化合物3g的X射线晶体学分析和所有产品的1H-NMR谱图表明,环丙基的构型在反应过程中保持不变。在相同的反应条件下,通过将异芳基/
三氟甲烷磷酸酯与具有光学纯度的环丙基
硼酸进行交叉偶联,可以获得高光学活性的环丙基取代异
芳烃(高达94% ee)。