Copper-catalyzed aryl amination in aqueous media with 2-dimethylaminoethanol ligand
作者:Zhikuan Lu、Robert J. Twieg
DOI:10.1016/j.tetlet.2005.03.027
日期:2005.4
Copper-catalyzedamination of aryl bromides and iodides under mild conditions has been developed with 2-dimethylaminoethanol as ligand and water as solvent. A variety of hydrophilic and hydrophobic arylhalide substrates have been aminated in good yield with a variety of amino acids, amino alcohols and peptides. This method has successfully N-arylated some hydrophilic amino compounds not available
Herein, we report the natural ligand quebrachitol (QCT) as a promoter for a Cu(II) catalyst, which is highly effective for N-arylation of various amines and related arylhalides. A series of diarylamine derivatives were obtained in high yields by using diethylene glycol (DEG) as both ligand and solvent. The C–N coupling reactions proceed under mild conditions and exhibit good functional group tolerance
selective N-arylation of amines or azoles with aryl halides, methyl-α-d-glucopyranoside (MG) was found to function as a green ligand of copper powder. In addition, nitrogenheterocyclic amine compounds can also undergo the N-arylation coupling with heterocyclic aryl chlorides. This process allows access to a variety of aromatic amines and aryl azoles under mild reaction conditions, has good tolerance, and
showed high efficiency for the couplingreactions of aminoacids and inactive aryl halides to give N-aryl aminoacids. Under the catalytic conditions, not only α-amino acids, but also β-, γ-, and δ-amino acids have been coupled with aryl chlorides in moderate to high yields; in the case of optically pure β-amino acids as substrates, the optical purities of the coupling products retained.
Accelerating Effect Induced by the Structure of α-Amino Acid in the Copper-Catalyzed Coupling Reaction of Aryl Halides with α-Amino Acids. Synthesis of Benzolactam-V8
作者:Dawei Ma、Yongda Zhang、Jiangchao Yao、Shihui Wu、Fenggang Tao
DOI:10.1021/ja981662f
日期:1998.12.1
hydrophilic groups. No racemization was observed in most cases of this coupling reaction. After some controlled experiments, a possible mechanism including the π-complex and the intramolecular substitution reaction is proposed. Based on this catalyzed reaction, a facile and stereoselective synthesis of benzolactam-V8, a new PKC activator, is achieved.
光学纯的 α-氨基酸与芳基卤化物的偶联产生对映纯的 N-芳基-α-氨基酸,在 CuI 的催化下保留构型。即使对于富电子的芳基卤化物,该反应也可以在比典型的 Ullmann 缩合低得多的温度下完成,这表明该反应中存在由 α-氨基酸结构诱导的加速效应。具有较大疏水基团的α-氨基酸产生较高的偶联产率,而具有较小疏水基团的α-氨基酸仅产生较低的产率,并且对于具有亲水基团的那些没有检测到偶联产物。在该偶联反应的大多数情况下未观察到外消旋化。经过一些对照实验,提出了一种可能的机制,包括 π 络合物和分子内取代反应。