Metal Free Benzylation and Alkylation of Quinoxalin‐2(1
<i>H</i>
)‐ones with Alkenes Triggered by Sulfonyl Radical Generated from Sulfinic Acids
作者:Himangsu Sekhar Dutta、Ashfaq Ahmad、Afsar Ali Khan、Mohit Kumar、Raziullah、Dipankar Koley
DOI:10.1002/adsc.201901212
日期:2019.12.17
A metal‐free domino multicomponent reaction for the direct C−H benzylation and alkylation of quinoxalin‐2(1H)‐ones using alkenes is described. Triggered by the sulfonyl radical generated from sulfinic acid, the alkenes are transformed to alkyl radicals that react exclusively at the C‐3 position of quinoxalin‐2(1H)‐ones. Importantly, the method not only functionalizes medicinally important quinoxalin‐2(1H)‐one
A straightforward palladium-catalyzed oxidative C-3 arylation of quinoxalin-2(1H)-ones with arylboronicacids is reported. This protocol is compatible with a wide range of functional groups and allows construction of various biologically important quinoxalin-2(1H)-one backbones.
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.
Visible-light-induced decarboxylative acylation of quinoxalin-2(1<i>H</i>)-ones with α-oxo carboxylic acids under metal-, strong oxidant- and external photocatalyst-free conditions
作者:Long-Yong Xie、You-Shu Bai、Xiang-Qin Xu、Xia Peng、Hai-Shan Tang、Ying Huang、Ying-Wu Lin、Zhong Cao、Wei-Min He
DOI:10.1039/c9gc03899j
日期:——
A mild and eco-friendly visible-light-induced decarboxylative acylation of quinoxalin-2(1H)-ones and α-oxo carboxylic acids with ambient air as the sole oxidant at room temperature was established. The reaction proceeded efficiently without any metal catalysts, strong oxidants or external-photosensitizers, ultimately reducing the generation of waste.
Direct C–H difluoromethylation of heterocycles via organic photoredox catalysis
作者:Wei Zhang、Xin-Xin Xiang、Junyi Chen、Chen Yang、Yu-Liang Pan、Jin-Pei Cheng、Qingbin Meng、Xin Li
DOI:10.1038/s41467-020-14494-8
日期:——
an organophotocatalytic direct difluoromethylation of heterocycles using O2 as a green oxidant. The C-H oxidative difluoromethylation obviates the need for pre-functionalization of the substrates, metals and additives. The operationally straightforward method enriches the efficient synthesis of many difluoromethylated heterocycles in moderate to excellent yields. The direct difluoromethylation of pharmaceutical