Cobalt(III)-Catalyzed [4 + 2] Annulation of <i>N</i>-Chlorobenzamides with Maleimides
作者:Nachimuthu Muniraj、Kandikere Ramaiah Prabhu
DOI:10.1021/acs.orglett.8b04117
日期:2019.2.15
A Co(III)-catalyzed novel [4 + 2] annulation of N-chlorobenzamides with maleimides has been reported. Mostly, maleimides are known to furnish the Michael-type or 1,1-type cyclized products while treating with amides. In this reaction, maleimides furnished [4 + 2] annulated products in good yields at room temperature while being treated with the internal oxidizing N-chlorobenzamide as a directing group
Cobaltacycle synthesis via C–H activation has been achieved for the first time, providing key mechanisticinsight into cobalt catalytic chemistry. N-Chloroamides are used as a directing synthon for cobalt-catalyzed room-temperature C–H activation and construction of heterocycles. Alkynes as coupling partners allow convenient access to isoquinolones, a class of synthetically and pharmaceutically important
The synthesis of a set of cobalt(III)-complexes equipped with trisubstituted chiral cyclopentadienyl ligands is reported, and their steric and electronic parameters are mapped. The application potential of these complexes for asymmetric C-H functionalizations with 3d-metals is shown by the synthesis of dihydroisoquinolones from N-chlorobenzamides with a broad range of alkenes. The transformation proceeds
报道了一组配备三取代手性环戊二烯基配体的钴 (III) 配合物的合成,并绘制了它们的空间和电子参数。这些配合物在具有 3d 金属的不对称 CH 官能化方面的应用潜力通过从具有广泛烯烃的 N-氯苯甲酰胺合成二氢异喹诺酮类药物来展示。转化过程具有高达 99.5:0.5 er 的出色对映选择性和高区域选择性。对于这种反应类型,观察到的值优于基于铑 (III) 的最佳方法。此外,具有挑战性的底物(如烷基烯烃)也会与高区域选择性和对映选择性反应。
Cobalt(<scp>iii</scp>)-catalyzed redox-neutral [4+2]-annulation of <i>N</i>-chlorobenzamides/acrylamides with alkylidenecyclopropanes at room temperature
作者:Balu Ramesh、Masilamani Jeganmohan
DOI:10.1039/d1cc00654a
日期:——
An efficient synthesis of substituted 3,4-dihydroisoquinolinones through [4+2]-annulation of N-chlorobenzamides/acrylamides having a monodentate directing group with alkylidenecyclopropanes in the presence of a less expensive, highly abundant and air stable Co(III) catalyst via a C–H activation is demonstrated. In this reaction, the N–Cl bond of N-chlorobenzamide serves as an internal oxidant and thus
Cobalt(III)-Catalyzed C–H Activation/Annulation Cascade Reaction of N-Chlorobenzamides with 2-Acetylenic Ketones at Room Temperature
作者:Yong Wu、Zhouping Wu、Qinwen Zheng、Guanghui Lv、Ruizhi Lai、Yao Hu、Li Hai
DOI:10.1055/a-1794-1314
日期:2022.7
N-chlorobenzamides with 2-acetylenic ketones at roomtemperature is reported. This reaction sets N–Cl bond of N-chlorobenzamide as an internal oxidant, displaying broad functional group tolerance and excellent reverse selectivity of alkyne insertion under mild and safe conditions. The cascade reaction offers a straightforward and mild protocol to construct isoquinolones in high yields at room temperature