本文描述了在温和的反应条件下,在较短的反应时间内,钯(0)催化Ullmann型交叉偶联反应进行芳基卤化物的N-芳基化和O-芳基化的有效方法。合成了两个硫化膦配体及其相应的Pd(0)络合物,即[Pd(p 2 S 2)(dba)]和[Pd(pp 3 S 4)(dba)],其中p 2 S 2为1, 2-双(二苯基膦基)乙烷二硫化物,pp 3 S 4是三[2-(二苯基膦基)乙基]膦四硫化物,dba是二亚苄基丙酮。通过改变温度,溶剂,碱和催化剂的负载量,确定了使用碘代苯和苯并咪唑进行芳基化反应的最佳反应条件。使用碘代苯/溴苯和具有不同空间和电子性质的各种取代的芳基胺/苯酚/醇进行交叉偶联反应,从而以良好或优异的收率得到所需的N-芳基胺/二芳基醚/烷基芳基醚( 70–94%)。
A New, Efficient and Recyclable Lanthanum(III) Oxide- Catalyzed CN Cross-Coupling
作者:S. Narayana Murthy、B. Madhav、V. Prakash Reddy、Y. V. D. Nageswar
DOI:10.1002/adsc.200900691
日期:2010.12.17
A new and efficient protocol for the CN cross-coupling of aryl halides with heteroaromatic amines in the presence of lanthanum(III) oxide (10 mol%) as a recyclable catalyst, N,N′-dimethylethylenediamine (DMEDA) (20 mol%) and potassium hydroxide (KOH) as a base in dimethyl sulfoxide (DMSO) at 110 °C has been developed. This inexpensive catalytic system is highly effective towards the amination of aryl