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
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。
Rhodium(III)-Catalyzed Synthesis of Isoquinolines from Aryl Ketone<i>O</i>-Acyloxime Derivatives and Internal Alkynes
作者:Pei Chui Too、Yi-Feng Wang、Shunsuke Chiba
DOI:10.1021/ol102504b
日期:2010.12.17
isoquinolines from aryl ketone O-acyloxime derivatives and internal alkynes has been developed using [Cp*RhCl2]2−NaOAc as the potential catalyst system. The present transformation is carried out by a redox-neutral sequence of C−H vinylation via ortho-rhodation and C−N bond formation of the putative vinyl rhodium intermediate on the oxime nitrogen, where the N−O bond of oxime derivatives could work as an internal
CH/NOfunctionalizations by cobalt(III) catalysis allowed the expedient synthesis of a broad range of isoquinolines. Thus, internal and challenging terminal alkynes proved to be viable substrates for an isohypsic annulation, which was shown to proceed by a facile CH cobaltation.
Ç H /Ñ ö官能化由钴(III)催化使范围广泛的异喹啉的的适宜的合成。因此,内部和具有挑战性的末端炔烃被证明是一个isohypsic环,其通过示出一个浅显下进行可行的基板 ħcobaltation。
Hydroxylamine-<i>O</i>
-Sulfonic Acid (HOSA) as a Redox-Neutral Directing Group: Rhodium Catalyzed, Additive Free, One-Pot Synthesis of Isoquinolines from Arylketones
作者:Pragati Biswal、Bedadyuti Vedvyas Pati、Rajesh Chebolu、Asit Ghosh、P. C. Ravikumar
DOI:10.1002/ejoc.201901825
日期:2020.2.28
A new reactivity of hydroxylamine‐O‐sulfonic acid (HOSA) has been demonstrated as redox‐neutral directing group for rhodium‐catalyzed one‐pot synthesis of diverse isoquinolines. This protocol reveals the utility of HOSA as a dircting group for the addditive free C–H/N–O annulations. Moreover, the in situ cleavage of the directing group reduces one step making it as a step‐economical process.