Visible‐Light‐Induced Direct C−H Amination of Quinoxalin‐2(1
H
)‐ones
摘要:
AbstractA visible‐light‐induced direct C(sp2)−H amination of quinoxalin‐2(1H)‐ones toward the synthesis of substituted 3‐aminoquinoxalin‐2(1H)‐ones with TMSN3 has been firstly developed. This transformation achieved C(sp2)−H/N−H coupling in the absence of external ligand and oxidant. Notably, this methodology features mild reaction conditions, broad substrate scope and operational simplicity.magnified image
Metal-free visible-light-initiated direct C3 alkylation of quinoxalin-2(1<i>H</i>)-ones and coumarins with unactivated alkyl iodides
作者:Jun Sun、Hua Yang、Bo Zhang
DOI:10.1039/d1gc03992j
日期:——
visible-light-promoted direct C3 alkylation of quinoxalin-2(1H)-ones and coumarinsusing readily accessible unactivated alkyl iodides as alkylation reagents. By applying this new approach, a broad range of valuable 3-alkylated quinoxalin-2(1H)-ones and coumarins (55 examples) can be facilely obtained at room temperature, thus showing the wide utility of this protocol. Notably, this practical reaction occurs under
我们首次报告了使用容易获得的未活化烷基碘作为烷基化试剂对喹喔啉-2(1 H )-酮和香豆素进行可见光促进的直接 C3 烷基化。通过应用这种新方法,可以在室温下轻松获得各种有价值的 3-烷基化 quinoxalin-2(1 H )-ones 和香豆素 (55 个例子),从而显示了该协议的广泛实用性。值得注意的是,这种实际反应发生在无金属和无外部光催化剂的条件下,表现出广泛的底物范围和高官能团耐受性。
A combination of heterogeneous catalysis and photocatalysis for the olefination of quinoxalin-2(1<i>H</i>)-ones with ketones in water: a green and efficient route to (<i>Z</i>)-enaminones
features very mild conditions using a simple and cheap catalyst for the synthesis of (Z)-enaminones with moderate-to-good yields. Such a methodology successfully combines the heterogeneous Mannich reaction with photocatalysis, and provides a green and practical approach for the synthesis of potentially bioactive (Z)-enaminones with a 3,4-dihydroquinoxalin-2(1H)-one skeleton.
A highly efficient, transition metal- and oxidant-free, direct C(sp2)-H difluoromethylation of heterocyclesthrough visible light-induced electrontransfer was developed. The reaction afforded difluoromethyl heterocycles by only using photoexcited diacetyl. The reaction showed a broad substrate tolerance and gave the products in good yields. Moreover, the representative products exhibited potential
Green and efficient C–C bond cleavage/cyanoalkylation of quinoxalin-2(1H)-ones and other heteroarenes under visible light or sunlight irradiation is described. The reaction proceeds under mild conditions at room temperature without transition-metal catalysts and extra bases. Notably, the products enable facile transformations to various significant organic compounds.