Mono- and dinuclear cyclopalladates as catalysts for Suzuki–Miyaura cross-coupling reactions in predominantly aqueous media
作者:G. Narendra Babu、Samudranil Pal
DOI:10.1016/j.tetlet.2017.01.089
日期:2017.3
Suzuki–Miyaura cross-coupling reactions of aryl halides with arylboronic acids were performed in predominantly aqueous media employing two mono- and two dinuclear cyclopalladated complexes as catalysts. These complexes are [Pd(HL)Cl] (I), [Pd(L)(PPh3)] (II), [Pd2(μ-dppb)(L)2] (III) and [Pd2(μ-dppf)(L)2] (IV); where H2L, dppb and dppf represent 4-methoxy-N′-(mesitylidene)benzohydrazide, 1,4-bis(dip
芳基卤化物与芳基硼酸的Suzuki-Miyaura交叉偶联反应主要在水性介质中进行,使用两个单核和两个双核环钯配合物作为催化剂。这些络合物为[Pd(HL)Cl](I),[Pd(L)(PPh 3)](II),[Pd 2(μ- dppb)(L)2 ](III)和[Pd 2(μ -dppf)(L)2 ](IV);其中H 2 L,dppb和dppf代表4-甲氧基-N′-(间亚甲基)苯甲酰肼,1,4-双(二苯基膦基)丁烷和1,1′-双(二苯基膦基)二茂铁。反应是在四丁基溴化铵(TBAB)存在下,以碳酸钾为碱,在二甲基甲酰胺-水(1:20)混合物中,于70/90°C下进行的。在所用的四种催化剂中,双核络合物IV证明是最有效的,并提供了中等至优异的收率,具有广泛的底物范围。