通过芳基酮,羟胺和炔烃的三组分反应,有效地一锅法合成异喹啉和杂环稠合吡啶。该反应涉及芳基酮和羟胺的缩合,铑(III)催化原位生成的芳基酮肟的C–H键活化以及与内部炔烃的环化作用。该协议能够从容易获得的底物中快速组装多取代的异喹啉以及γ-咔啉,呋喃[2,3- c ]吡啶,噻吩并[2,3- c ]吡啶和苯并呋喃[2,3- c ]吡啶。
Cp*-Free Cobalt-Catalyzed C–H Activation/Annulations by Traceless <i>N</i>,<i>O</i>-Bidentate Directing Group: Access to Isoquinolines
作者:Xiao-Cai Li、Cong Du、He Zhang、Jun-Long Niu、Mao-Ping Song
DOI:10.1021/acs.orglett.9b00866
日期:2019.4.19
N,O-Bidentate directing-enabled, traceless heterocycle synthesis is described via Cp*-free cobalt-catalyzedC–Hactivation/annulation. The weakly coordinating nature of the carboxylic acid was employed for the preparation of isoquinolines. Meanwhile, the N–Obond of the α-imino-oxy acid can serve as an internaloxidant. Terminal as well as internalalkynes can be efficiently applied to the catalytic
A rhodium-catalyzed sequential oxidativeC–H annulation reaction between ketazines and internal alkynes has been developed via C–H and N–N bond activation with air as an external oxidant, which led to an efficient approach toward isoquinolines with high atom efficiency at rt. Utilizing the distinctive reactivity of this catalysis, both N-atoms of the azines could be efficiently incorporated to the
The electrochemical three‐componentassembly of isoquinolines has been accomplished by ruthenaelectro‐catalyzed C−H/N−H functionalization. The robustness of the electrocatalysis was reflected by an ample substrate scope, an efficient electrooxidation, and an operationally friendly procedure. The isolation of key intermediates and detailed mechanistic studies, including unprecedented cyclovoltammetric
异喹啉的电化学三组分组装已通过钌电子催化的CH / NH官能团完成。电催化的坚固性通过足够的底物范围,有效的电氧化作用和操作友好的程序得以体现。关键中间体的分离和详细的机理研究,包括对七元钌循环的前所未有的循环伏安分析,为不寻常的钌(II / III / I)机制提供了支持。
<i>N</i>-Tosylhydrazone directed annulation <i>via</i> C–H/N–N bond activation in Ru(<scp>ii</scp>)/PEG-400 as homogeneous recyclable catalytic system: a green synthesis of isoquinolines
作者:Dewal S. Deshmukh、Bhalchandra M. Bhanage
DOI:10.1039/c8ob01082j
日期:——
of isoquinolines using Ru(II)/PEG-400 as a homogeneous recyclable catalytic system has been demonstrated. N-Tosylhydrazone, a rarely explored directing group, has been successfully employed for an annulation type of reaction with alkynes viaC–H/N–N activation. A short reaction time with a simple extraction procedure, a wide substrate scope with high yields of products, easily prepared substrates, biodegradable
Cobalt(III)-Catalyzed Dehydrative [4+2] Annulation of Oxime with Alkyne by CH and NOH Activation
作者:Malay Sen、Deepti Kalsi、Basker Sundararaju
DOI:10.1002/chem.201503643
日期:2015.10.26
Efficient, scalable cobalt‐catalyzed redox‐neutral [4+2] annulation of readily available oximes and alkyne is reported. The developed synthetic methodology is widely applicable and tolerates various functional groups including heterocycles. A stable Cp*CoIII neutral complex is employed as the catalyst for this redox‐neutral [4+2] annulation reaction, which progresses smoothly by way of a reversible
据报道,高效,可扩展的钴催化的氧化还原中性[4 + 2]环化易于获得的肟和炔烃。所开发的合成方法学广泛适用,并能耐受包括杂环在内的各种官能团。稳定的Cp * Co III中性络合物用作该氧化还原-中性[4 + 2]环化反应的催化剂,该反应通过可逆的环金属化反应顺利进行,而无需任何外部氧化剂,仅产生水作为副产物。