Rhodium(III)-Catalyzed Directed C−H Amidation of <i>N</i>
-Nitrosoanilines and Subsequent Formation of 1,2-Disubstituted Benzimidazoles
作者:Yanyu Chen、Rong Zhang、Qiujun Peng、Lanting Xu、XianHua Pan
DOI:10.1002/asia.201701287
日期:2017.11.2
An efficient rhodium‐catalyzeddirectC−Hamidation of N‐nitrosoanilines with 1,4,2‐dioxazol‐5‐ones as amidating agents has been developed. This method featured mild reaction conditions, a wide substrate scope and satisfactory yields. Besides, the amidated products could be readily converted to pharmaceutically valuable 1,2‐disubstituted benzimidazoles via an HCl‐mediated deprotection/cyclization process
Gold nanoparticles supported on titanium dioxide: an efficient catalyst for highly selective synthesis of benzoxazoles and benzimidazoles
作者:Lin Tang、Xuefeng Guo、Yu Yang、Zhenggen Zha、Zhiyong Wang
DOI:10.1039/c4cc01822b
日期:——
A highly efficient and selective reaction for the synthesis of 2-substitutedbenzoxazoles and benzimidazoles catalyzed by Au/TiO2 has been developed via two hydrogen-transfer processes. This reaction has a good tolerance to air and water, a wide substrate scope, and represents a new avenue for practical C-N and C-O bond formation. More importantly, no additional additives, oxidants and reductants are
Aerobic Oxidative Coupling of Amines by Carbon Nitride Photocatalysis with Visible Light
作者:Fangzheng Su、Smitha C. Mathew、Lennart Möhlmann、Markus Antonietti、Xinchen Wang、Siegfried Blechert
DOI:10.1002/anie.201004365
日期:2011.1.17
Coupling on sunshine: A simple and efficient synthesis of benzoxazoles, benzimidazoles, and benzothiazoles is realized through a one‐pot preparation driven by a photocatalyticcascade reaction. Carbon nitride and visiblelight are employed to achieve this metal‐free aerobic oxidation of amines to imines (see scheme; mpg‐C3N4=mesoporous graphite carbon nitride).
阳光下的耦合:通过光催化级联反应驱动的一锅法制备,可实现苯并恶唑,苯并咪唑和苯并噻唑的简单有效合成。氮化碳和可见光可用于实现胺向亚胺的无金属需氧氧化(请参阅方案; mpg-C 3 N 4 =中等石墨氮化碳)。
Copper and Iron-assisted Palladium-catalyzed Direct Arylation of Azoles with Arylboronic Acids under Ligand and Base-free Conditions
作者:Xiang-Mei Wu、Qiu-Xian Shen
DOI:10.2174/15701786113109990034
日期:2013.9.1
The direct arylation of azoles with arylboronic acids is effectively promoted by PdCl2 in the presence of copper
and iron salts under ligand and base-free conditions. This reaction can be applied to heterocycles such as benzothiazole,
benzoxazole, 1-methylbenzimidazole and 4,5-dimethylthiazole with moderate to good yields.
Ligand-Free CuO Nanospindle Catalyzed Arylation of Heterocycle C–H Bonds
作者:Wu Zhang、Qinglong Zeng、Xinming Zhang、Yujie Tian、Yun Yue、Yujun Guo、Zhenghua Wang
DOI:10.1021/jo200452x
日期:2011.6.3
have been developed to efficiently catalyze the direct arylation of heterocycle C–H bonds with moderate to excellent yields. This reaction can be applied to heterocycles such as benzoxazole, benzothiazole, and 1-methylbenzimidazole in the presence of a more environmentally friendly inorganic base like K2CO3 underligand-free catalytic conditions. In addition, the catalyst can be recycled and reused
CuO纳米锭已经被开发出来,可以以中等到极高的产率有效地催化杂环C–H键的直接芳基化。该反应可在无配体的催化条件下,在更环境友好的无机碱(如K 2 CO 3)存在下,应用于诸如苯并恶唑,苯并噻唑和1-甲基苯并咪唑的杂环上。另外,催化剂可以循环使用,而催化活性没有明显降低。