N-Heterocyclic Carbene-Assisted, Bis(phosphine)nickel-Catalyzed Cross-Couplings of Diarylborinic Acids with Aryl Chlorides, Tosylates, and Sulfamates
作者:Haihua Ke、Xiaofeng Chen、Gang Zou
DOI:10.1021/jo501291y
日期:2014.8.1
Ni(PPh3)2Cl2/[Bmim]Br displayed high catalytic activities in the cross-couplings of diarylborinic acids. The structural influences from diarylborinic acids were found to be rather small, while electronic factors from aryl chlorides, tosylates, and sulfamates affected the couplings remarkably. The couplings of electronically activated aryl chlorides, tosylates, and sulfamates could be efficiently effected with
二芳基硼酸与芳基氯化物,甲苯磺酸盐和氨基磺酸盐的高效双(膦)镍催化交叉偶联已经在由N,N'-二烷基咪唑鎓盐(例如N)原位生成的N-杂环卡宾(NHC)的帮助下进行了丁基- ñ '甲基咪唑溴化物([BMIM] BR),在用k甲苯3 PO 4 ·3H 2 O为基础。与双(NHC)镍催化的传统Suzuki芳基硼酸偶联反应不同,Ni(PPh 3)2 Cl 2原位生成单(NHC)双(膦)镍物种/ [Bmim] Br在二芳基硼酸的交叉偶联中显示出高催化活性。发现二芳基硼酸的结构影响很小,而芳基氯化物,甲苯磺酸盐和氨基磺酸盐的电子因素则显着影响偶联。以1.5 mol%NiCl 2(PPh 3)2 / [Bmim] Br作为催化剂前体可以有效地实现电子活化的芳基氯化物,甲苯磺酸盐和氨基磺酸盐的偶联,从而以3-5 mol%的高收率得到联芳基产品。加载必须用于非激活和停用的耦合。小邻里芳基氯,甲苯磺酸酯和氨基磺