@article {43948, title = {Heterogeneously catalyzed domino synthesis of 3-indolylquinones involving direct oxidative C-C coupling of hydroquinones and indoles}, journal = {ACS Omega}, volume = {2}, year = {2017}, month = {MAY}, chapter = {2238-2247}, abstract = {
Abstract Image

A domino synthesis of 3-indolylquinones was achieved successfully via direct oxidative C{\textendash}C coupling of hydroquinones with indoles over Ag2O and Fe3O4/povidone{\textendash}phosphotungstic acid (PVP{\textendash}PWA) catalysts using H2O2\ in tetrahydrofuran at room temperature. Ag2O catalyzed the in situ oxidation of hydroquinone and 3-indolylhydroquinone intermediates, whereas ferrite solid acid, Fe3O4/PVP{\textendash}PWA, with a 1:4:1 ratio of Fe3O4, PVP, and PWA, catalyzed the activation of quinones. The efficiency of this catalytic domino approach was established by a broad scope of substrates involving a variety of hydroquinones and quinones to give high yields (81{\textendash}97\%) of 3-indolylquinones. Fe3O4/PVP{\textendash}PWA was separated magnetically, whereas simple filtration could separate Ag2O, both of which could be recycled several times without losing their activities.

}, keywords = {Carbonyl compounds (organic); Electron microscopy; Fourier-transform spectroscopy; Redox reaction}, doi = {10.1021/acsomega.7b00201}, author = {Kamble, Sumit B.; and Vyas, Praneet P. and Jayaram, Radha V.; and Rode, Chandrashekhar V.} }