Synthesis of polynuclear heterocycles via the reaction of α-ester carbanions with quaternized nicotinamide salts. A facile stereoselective synthesis of sesbanine
Copper-catalyzed selective difunctionalization of N-heteroarenes through a halogen atom transfer radical process
作者:Hui-Lin Fang、Qiu Sun、Rong Ye、Jing Sun、Ying Han、Chao-Guo Yan
DOI:10.1039/c9nj03471d
日期:——
A highly regioselective Cu-catalyzed difunctionalization of different N-heteroarene salts such as quinolinium and benzothiazolim salts was developed with ether and X− (X = Br, Cl) as the halogen source under mild conditions. This transformation involved the combination of oxidative coupling, selective free radical resonance and a copper-catalyzed halogen atom-transfer radical process. The regiochemistry
various reactions involving electron pairs. However, it was found that ylides resulting from deprotonation of N-alkyl-substituted pyridinium salts exhibit radical characters, with no discernable NMR signals but decent EPR spectra in both solution and the solidstate. An observed correlation between lowered π* energy level of the pyridinium ring and increased EPR activity indicates that thermally induced
Light-driven selective aerobic oxidation of (iso)quinoliniums and related heterocycles
作者:Meimei Zhou、Keyang Yu、Jianxin Liu、Weimei Shi、Yingming Pan、Haitao Tang、Xiangjun Peng、Qian Liu、Hengshan Wang
DOI:10.1039/d1ra01226f
日期:——
Selective C1–H/C4–H carbonylation of N-methylene iminium salts, catalyzed by visible-light photoredox and oxygen in the air, has been reported. A ruthenium complex acts as a chemical switch to conduct two different reaction pathways and to afford two different kinds of products. In the absence of the ruthenium complex, the Csp2–H bondsadjacent to the nitrogenatoms are oxidized to α-lactams by the
AbstractAn efficient and facile method for the synthesis of novel naphthooxazocines from 2-hydroxy-1,4-naphthoquinone and quinolinium salts at room temperature is described. The reaction proceeds through C-alkylation and intramolecular O-alkylation, affording the desired products in good yields. Graphical abstract