An efficient and novel electrochemical oxidative tandem cyclization of arylketones and benzylamines for the synthesis of 1,2,4-trisubstituted-(1H)-imidazoles has been developed under metal- and oxidant-free conditions. This direct C-N bond formation strategy, with a broad functional group tolerance, affords the desired imidazoles in moderate to excellent yields.
CuI/BF<sub>3</sub>·Et<sub>2</sub>O Cocatalyzed Aerobic Dehydrogenative Reactions of Ketones with Benzylamines: Facile Synthesis of Substituted Imidazoles
作者:Zhong-Jian Cai、Shun-Yi Wang、Shun-Jun Ji
DOI:10.1021/ol302955u
日期:2012.12.7
A novel CuI/BF3·Et2O/O2-mediated reaction utilizing ketones and benzylamines for the construction of substituted imidazoles in one step under mild conditions has been demonstrated. This protocol involved the removal of eight hydrogen atoms, the functionalization of four C(sp3)–H bonds and three new C–N bond formations.
已经证明了在温和条件下一步一步利用酮和苄胺介导的新型CuI / BF 3 ·Et 2 O / O 2介导的反应,用于构建取代的咪唑。该协议涉及去除八个氢原子,四个C(sp 3)–H键的功能化和三个新的C–N键的形成。
I<sub>2</sub>-catalyzed synthesis of substituted imidazoles from vinyl azides and benzylamines
作者:Likui Xiang、Yanning Niu、Xiaobo Pang、Xiaodong Yang、Rulong Yan
DOI:10.1039/c5cc01155h
日期:——
A novel and efficient I2-catalyzed oxidative tandem cyclization of simple vinyl azides and benzylamines has been developed for the synthesis of substituted imidazoles.
A novel and practical method for the construction of 1,2,4-trisubstituted imidazoles with enamides and benzylamines catalysed by CuBr and I2 has been developed. This sustainable, simple and environmentally-friendly procedure tolerates various functional groups and affords a series of trisubstitued imidazoles.
A facile synthesis of 1H-imidazoles by direct oxidative annulation of aryl methylketones and primary amines has been developed in the presence of TEMPO under weakly acidic conditions. By replacing amines with ammonium acetate, 2H-imidazole skeletons were achieved for the first time from ketones. Substrates containing various functional groups, such as alkyl, aryl, naphthyl, halogen (F, Cl, Br, I)
在弱酸性条件下,在 TEMPO 存在下,通过芳基甲基酮和伯胺的直接氧化环化,开发了一种简便的 1 H-咪唑合成方法。通过用乙酸铵代替胺类,首次从酮类中获得了2 H-咪唑骨架。含有各种官能团的底物,如烷基、芳基、萘基、卤素(F、Cl、Br、I)、硝基、三氟甲基、磺酰基酯、呋喃基、噻吩基和吡啶基,很容易转化为所需的产物。通过咪唑的放大合成和 Sonogashira 偶联功能化验证了该方法的应用潜力。从机理上讲,α-TEMPO-烯胺加合物可以作为关键的反应中间体。