Intramolecular Oxidative C−N Bond Formation for the Synthesis of Carbazoles: Comparison of Reactivity between the Copper-Catalyzed and Metal-Free Conditions
作者:Seung Hwan Cho、Jungho Yoon、Sukbok Chang
DOI:10.1021/ja111652v
日期:2011.4.20
New synthetic procedures for intramolecular oxidative C-N bondformation have been developed for the preparation of carbazoles starting from N-substituted amidobiphenyls under either Cu-catalyzed or metal-freeconditions using hypervalent iodine(III) as an oxidant. Whereas iodobenzene diacetate or bis(trifluoroacetoxy)iodobenzene alone undergoes the reaction to provide carbazole products in moderate
已经开发了用于分子内氧化 CN 键形成的新合成程序,用于在 Cu 催化或无金属条件下使用高价碘 (III) 作为氧化剂从 N 取代的酰氨基联苯制备咔唑。虽然二乙酸碘苯或双(三氟乙酰氧基)碘苯单独进行反应以提供中低收率的咔唑产物,但三氟甲磺酸铜(II)和碘(III)物质的组合使用显着提高了反应效率,提供了更多样化的范围产品良率高。在包括动力学曲线、同位素效应和自由基抑制实验在内的机理研究的基础上,铜物种被提议用于催化激活高价碘 (III) 氧化剂。
Reported herein is an environmentally benign electrochemical C−H bond dehydrogenative amination protocol for the construction of privileged carbazole moiety with broad generality. Preliminary mechanistic investigations implied a radical reaction pathway. Compared with traditional ionic routes, the scalable transition‐metal and exogenous‐oxidant free strategy highlighted the green and sustainable nature
Synthesis of substituted carbazoles via electrocyclization of in situ generated enamines from 1-phenylsulfonyl-2/(3)-methyl-3/(2)-vinylindoles and DMF·DMA/DMA·DMA
作者:Radhakrishnan Sureshbabu、Ramalingam Balamurugan、Arasambattu K. Mohanakrishnan
DOI:10.1016/j.tet.2009.03.010
日期:2009.5
Interaction of 2/(3)-methyl-3/(2)-vinylindoles and DMF center dot DMA/DMA center dot DMA at 110 degrees C led to the in situ generation of enamines, which on concurrent electrocyclization followed by subsequent aromatization afforded substituted carbazoles. (C) 2009 Elsevier Ltd. All rights reserved.
An Improved Synthesis of Carbazoles<i>via</i>Domino Reaction of<i>N</i>-Protected-2-methylindoles with DMF-DMA/DMA-DMA
作者:Radhakrishnan Sureshbabu、Arasambattu K. Mohanakrishnan
DOI:10.1002/jhet.899
日期:2012.7
An efficient synthesis of carbazole analogs has been achieved via interaction of N‐protected‐2‐methylindoles with N,N‐dimethylformamide dimethylacetal as well as N,N‐dimethylacetamide dimethylacetal in the presence of pyrrolidine or 1,4‐diazabicyclo(2.2.2)octane (DABCO).
A novel synthesis of N-protected carbazoles involving electrocyclization of in situ generated enamines
作者:Arasambattu K. Mohanakrishnan、Ramalingam Balamurugan
DOI:10.1016/j.tetlet.2005.04.016
日期:2005.6
A new route for the synthesis of carbazoles has been realized through the intermediacy of 2,3-divinylindoles involving an electrocyclization followed by aromatization. (c) 2005 Elsevier Ltd. All rights reserved.