Iminyl radicals are reactive intermediates that can be used for the construction of various valuable heterocycles. Herein, the electrochemical decarboxylation of α-imino-oxy acids for the generation of iminyl radicals has been accomplished under exogenous-oxidant- and metal-free conditions through the use of nBu4NBr as a mediator. The resulting iminyl radicals undergo intramolecular cyclization smoothly
亚胺基是反应性中间体,可用于构建各种有价值的杂环。在此,通过使用n Bu 4 NBr 作为介体,在无外源氧化剂和无金属条件下完成了用于产生亚胺基自由基的 α-亚氨基-羟基酸的电化学脱羧。所得亚胺基自由基与相邻的(杂)芳烃顺利进行分子内环化,得到一系列吲哚稠合的多环化合物。
Copper-Mediated Intramolecular Oxidative C–H/C–H Cross-Coupling of α-Oxo Ketene <i>N</i>,<i>S</i>-Acetals for Indole Synthesis
CuCl2-mediated intramolecular C-H/C-H cross-dehydrogenative coupling (CDC) of thioalkyl-substituted a-acetyl or alpha-aroyl ketene N,S-acetals afforded 2-thioalkyl indoles. Tunable C-S bond transformations of the resultant indoles led to highly functionalized N-heterocyclic compounds. A beta-thioalkyl is necessary to activate the N,S-acetal substrate and enable the CDC reaction to occur, and the relevant mechanism studies revealed that the CDC reaction follows a radical pathway.
A competitive and highly selective 7-, 6- and 5-annulation with 1,3-migration through C–H and N–H – alkyne coupling
作者:Sk Ajarul、Anirban Kayet、Tanmay K. Pati、Dilip K. Maiti
DOI:10.1039/c9cc07360d
日期:——
We demonstrated a highly competitive and selective C-C and N-C cross-coupled 7-, 6- and 5-annulation utilizing 2-ethynylanilides to afford functionalized 1H-benzo[b]azepin-2(5H)-ones, 2-quinolinones, and 3-acylindoles in high yield. ZnCl2 was found to be the smart catalyst for 7- and 5-annulation with 1,3-migration through C-H and N-H functionalization, respectively, whereas molecular iodine performed