Domino C–H functionalization reactions of gem-dibromoolefins: synthesis of N-fused benzo[c]carbazoles
作者:Richard Y. Huang、Patrick T. Franke、Norman Nicolaus、Mark Lautens
DOI:10.1016/j.tet.2013.01.001
日期:2013.6
A palladium-catalyzed domino transformation of gem-dibromoolefins leading to novel polycyclic benzo[c]carbazoles is described. A unique feature of the current reaction is the participation of both bromides in C–H functionalization processes. Mechanistic studies were conducted to ascertain the sequence of reaction events, and the results indicate that the (Z)-bromide likely reacts in preference to the
描述了钯-催化的宝石-二溴烯烃的多米诺转化,其导致了新型的多环苯并[ c ]咔唑。当前反应的一个独特特征是两种溴化物都参与了CH的H官能化过程。进行了机理研究以确定反应事件的顺序,结果表明(Z)-溴化物可能优先于(E)-溴化物反应。
Electrochemical
<scp>Palladium‐Catalyzed</scp>
Intramolecular C—H Amination of
<scp>2‐Amidobiaryls</scp>
for Synthesis of Carbazoles
作者:Qingqing Wang、Xiaojing Zhang、Pan Wang、Xinlong Gao、Heng Zhang、Aiwen Lei
DOI:10.1002/cjoc.202000407
日期:2021.1
The synthesis of carbazoles based on the electrochemical Pd‐catalyzed intramolecularC—H amination of 2‐amidobiaryls through oxidative cross coupling has been achieved under mild reaction conditions. The reaction can be carried out in undivided cell without the addition of external chemical oxidant. Besides good functional group compatibility, the desired carbazoles can be scaled up and modified easily
A facile synthesis of carbo- and heterohelicenes was achieved via tandem cycloaromatization of bisacetal precursors, which were readily prepared through C–C bond formation by Suzuki–Miyaura coupling. This cyclization was efficiently realized by a catalytic amount of trifluoromethanesulfonic acid (TfOH) in a cation-stabilizing solvent, 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP), which readily allowed
Transition metal-catalyzed diamination by hydroxylamines is a common approach for making three-membered aziridines, while its use for building the larger N-heterocycles is still underdeveloped. Herein, we report an efficient Pd(0)-catalyzed inter-molecular [4+1] annulation of o-bromo(or chloro)-biaryls with bifunctional secondary hydroxylamines for the one-step assembly of synthetically useful carbazoles
羟胺的过渡金属催化二化是制备三元氮丙啶的常用方法,而其用于构建较大的N-杂环的用途仍未开发。在此,我们报告了一种有效的 Pd(0) 催化的分子间 [4+1] 环化邻溴(或氯)-联芳基与双功能仲羟胺,用于一步组装合成有用的咔唑。值得注意的是,这种多米诺骨牌反应的关键是明智地选择氨基源和 Pd(0)-催化剂,以便在具有不稳定 NO 的羟胺存在下将芳基卤化物氧化加成到 Pd(0)-物种中。键。