arylnitrones and diazo compounds by C–H activation/[4 + 1] annulation with a C(N2)–C(acyl) bond cleavage is reported, and 2,3-disubstituted NH indoles are directly synthesized in up to a 94% yield. A variety of functional groups are applicable to this reaction to give the corresponding products with high selectivity. Compared to other previously reported Rh(III)-catalyzed synthesis of homologous series, this method
I2-Catalyzed Indole Formation via Oxidative Cyclization of N-Aryl Enamines
作者:Zhiheng He、Weiping Liu、Zhiping Li
DOI:10.1002/asia.201100045
日期:2011.6.6
Cat.′s Is: An I2‐catalyzed synthesis of indoles, taking advantage of intramolecular dehydrogenative coupling reactions of enamines, afforded a variety of multifunctionalized indole derivatives in good to excellent yields under transition‐metal‐free reaction conditions.
An Oxidant-Free Strategy for Indole Synthesis via Intramolecular C–C Bond Construction under Visible Light Irradiation: Cross-Coupling Hydrogen Evolution Reaction
We describe here an oxidant-free strategy to synthesize indoles, i.e., under visible-light irradiation (λ = 450 nm), catalytic amounts of an iridium(III) photosensitizer and cobaloxime catalyst transform various N-arylenamines exclusively into indoles. Our methodology affords indoles in good to excellent yields under mild reaction conditions and produces H2 as the only byproduct. Spectroscopic and
The construction of substituted indole skeletons is always an important concern of synthetic chemists because of its prevalent structure found in natural products and biological molecules. Here, we succeeded in preparing indoles and their derivativesfrom a wide variety of simple enamines viaradical cyclization only with catalytic amounts of an iridium(III) photosensitizer (PS) in DMSO solution under
Base-promoted, CBr<sub>4</sub>-mediated tandem bromination/intramolecular Friedel–Crafts alkylation of <i>N</i>-aryl enamines: a facile access to 1<i>H</i>- and 3<i>H</i>-indoles
作者:Lan Zhao、Changfu Qiu、Lixin Zhao、Guangwei Yin、Fangyi Li、Chunhua Wang、Zheng Li
DOI:10.1039/d1ob00731a
日期:——
is a general and highly efficient method for the synthesis of 1H- and 3H-indoles. In the presence of CBr4 and a suitable base, the cyclization of N-aryl enamines proceeds with high efficiency. Unlike previous intramolecular crossdehydrogenativecoupling (CDC) of the same substrates, this process does not require the use of either a transitionmetal or a stoichiometric amount of oxidant. This method
这里描述的是一种合成 1 H - 和 3 H - 吲哚的通用且高效的方法。在CBr 4和合适的碱存在下, N-芳基烯胺的环化以高效率进行。与以前的相同底物的分子内交叉脱氢偶联 (CDC) 不同,该过程不需要使用过渡金属或化学计量的氧化剂。该方法还具有操作简单、易于扩展和良好的底物耐受性等特点。对照实验表明,反应可以在简单的一锅法中以溴化和分子内傅克烷基化的串联顺序进行。