A new one‐pot palladium‐catalyzed process between N‐tosylhydrazones, N‐(dihalophenyl)‐imidates, and amines was designed. This reaction involves Barluenga cross‐coupling and N‐arylation followed by cyclization to produce functionalized benzimidazoles. During this transformation, one CC bond and two CN bonds were created by a single palladium‐catalyzed reaction. Depending on the starting materials
Unsymmetric, N-substituted benzimidazoles and imidazopyridines can be prepared directly from 2-halonitroarenes and amides through Pd(TFA) 2 /(R)-BINAP-catalyzed cross-coupling and subsequent reductive aminocyclization. This sequence can be conducted by a one-pot procedure. The method is versatile and allows the straightforward, regioselective preparation of these important nitrogen heterocycles.
designed and demonstrated for the synthesis of Cu nanorods. The Fe3O4@SiO2/EP.EN.EG@Cu was characterized using X‐ray diffraction, thermogravimetric analysis, transmission electron microscopy, energy‐dispersive X‐ray spectroscopy and vibrating sample magnetometry. The Fe3O4@SiO2/EP.EN.EG@Cu showed excellent catalytic efficiency for the cross‐couplingreaction of nitrogen‐containing heterocycles with aryl
设计了一种新型的负载在Fe 3 O 4 @SiO 2上的多齿配体,并证明了其可用于合成Cu纳米棒。Fe 3 O 4 @SiO 2 /EP.EN.EG@Cu的特征在于使用X射线衍射,热重分析,透射电子显微镜,能量色散X射线光谱法和振动样品磁强度法。Fe 3 O 4 @SiO 2/EP.EN.EG@Cu对含氮杂环与芳基卤化物的交叉偶联反应显示出优异的催化效率。只需施加外部磁场即可有效地从反应混合物中分离出催化剂,并至少重复使用五次而不会损失活性。
DAST-promoted Beckmann rearrangement/intramolecular cyclization of acyclic ketoximes: access to 2-oxazolines, benzimidazoles and benzoxazoles
作者:Huiqin Li、Jian Qin、Zonglian Yang、Xiaoxue Guan、Lin Zhang、Peiqiu Liao、Xingqi Li
DOI:10.1039/c5cc02155c
日期:——
The first example of DAST-promoted Beckmann rearrangement/intramolecular cyclization of acyclic ketoximes is described, which affords 2-oxazolines, benzimidazoles and benzoxazoles.
Synthesis of 1,2-disubstituted benzimidazoles using an aza-Wittig-equivalent process
作者:Yuan Chen、Fanghui Xu、Zhihua Sun
DOI:10.1039/c7ra09010b
日期:——
A synthetic approach for 1,2-disubstituted benzimidazoles has been successfully designed based on effective C–N bond construction, which demonstrated mild reaction conditions and excellent yields. The method involves treating derivatives of o-phenylenediamine with tert-butanesulfoxide and NBS under acidic conditions, which undergoes an aza-Wittig-equivalent process to afford the desired products. Using