A base-modulated chemoselective synthesis of 3-cyanoindoles or 4-cyanoquinolines using a palladium-catalyzed N-heterocyclization
摘要:
A selective methodology for the synthesis of either 3-cyanoindoles or 4-cyanoquinolines via a base-modulated palladium-catalyzed reductive N-heterocyclization from a common 1-cyano-1-(2-nitrophenyl)-1-alkene precursor is described. The required starting materials were prepared either by a Kosugi Migita Stille coupling of 2-halo-1-nitrobenzenes with a tributyl(1-alkenyl)stannane or by a vicarious nucleophilic substitution (VNS) of nitrobenzenes followed by a Knoevenagel condensation with an aldehyde. (C) 2011 Elsevier Ltd. All rights reserved.
A simple and efficient one-potsynthesis of substituted indolo[1,2-a]quinolines under transition-metal-free conditions has been developed. When 2-fluorobenzaldehyde was treated with substituted 2-methylindoles in the presence of Cs2CO3, the desired products were typically obtained in good to excellent yields. This reaction sequence involves a nucleophilic aromatic substitution and a Knoevenagel condensation
已经开发了一种在无过渡金属条件下简单高效的一锅合成取代吲哚[1,2- a ]喹啉的方法。当在Cs 2 CO 3存在下用取代的2-甲基吲哚处理2-氟苯甲醛时,通常以良好或优异的产率获得所需产物。该反应序列涉及亲核芳族取代和Knoevenagel缩合反应。我们的机理研究表明,第一步中两个反应都可能以分子间反应的形式进行。
GaCl<sub>3</sub>-Catalyzed C–H Cyanation of Indoles with <i>N</i>-Cyanosuccinimide
作者:Xue Wang、Mohamed Makha、Shu-Wei Chen、Huaiji Zheng、Yuehui Li
DOI:10.1021/acs.joc.9b00416
日期:2019.5.17
An efficient GaCl3-catalyzed direct cyanation of indoles and pyrroles using bench-stable electrophilic cyanating agent N-cyanosuccinimide was achieved and afforded 3-cyanoindoles and 2-cyanopyrroles in good yields and excellent regioselectivities. Notably, this protocol exhibited high reactivity for unprotected indoles and was applicable to a broad range of indole and pyrrole substrates.
Lewis Acid Catalyzed Direct Cyanation of Indoles and Pyrroles with <i>N</i>-Cyano-<i>N</i>-phenyl-<i>p</i>-toluenesulfonamide (NCTS)
作者:Yang Yang、Yan Zhang、Jianbo Wang
DOI:10.1021/ol202335p
日期:2011.10.21
BF3·OEt2-catalyzed direct cyanation of indoles and pyrroles using a less toxic, bench-stable, and easily handled electrophilic cyanating agent N-cyano-N-phenyl-para-toluenesulfonamide (NCTS) affords 3-cyanoindoles and 2-cyanopyrroles in good yields with excellent regioselectivity. The substrate scope is broad with respect to indoles and pyrroles.
An efficient trans‐PdCl2(NH2CH2COOH)2‐catalyzed direct C3‐cyanation of indole C─H bonds is described. Notably, free (N─H)‐indoles reacted smoothly using the procedure, and the desired product 3‐cyanoindoles were obtained in good to excellent yields.