Pd-Catalyzed Redox-Neutral C–N Coupling Reaction of Iminoquinones with Electron-Deficient Alkenes without External Oxidants: Access of Tertiary (<i>E</i>)-Enamines and Application to the Synthesis of Indoles and Quinolin-4-ones
A novel and efficient reductive N-alkenylation of iminoquinones with electron-deficient olefins has been successfully developed by Pd(II)-catalyzed redox-neutral reactions, which provides a synthesis of tertiary (E)-enamines. We further demonstrate that the tertiary enamines can be converted to multifarious N-heterocyclic compounds, indoles, and quinolones in good yields.
with urea–hydrogen peroxide using iron(III) and manganese (III)- tetraphenylporphyrins [Fe(TPP)Cl], [Mn(TPP)Cl] and manganese (III)-octabromotetraphenyl porphyrin [Mn(TPPBr8)Cl] as catalysts. Experimental results showed the released urea from UHP acts as an axial ligand. These catalysts showed high selectivity in oxidation of imines to corresponding nitrones and oxaziridines at 0°C to room temperature
Cycloaddition reactions of quinoneimine N-oxides and of fluorenoneimine N-oxide: exocyclic nitrones conjugated with electron-withdrawing rings
作者:Jaffar A. Damavandy、Richard A. Y. Jones
DOI:10.1039/p19810000712
日期:——
N-Phenyl-p-benzoquinoneimine N-oxide is generally unreactive in 1,3-dipolar cycloaddition reactions, but with acetylenedicarboxylate esters it gives indolones, formed from the initial adducts by a rearrangement which entails an alkoxycarbonyl migration. The analogous nitrone derived from anthraquinone gives unrearranged adducts with a variety of 1,3-dipolarophiles; monosubstituted alkynes and alkenes