Heterogeneously Catalyzed Domino Synthesis of 3-Indolylquinones Involving Direct Oxidative C–C Coupling of Hydroquinones and Indoles
Author(s) -
Sumit B. Kamble,
Praneet P. Vyas,
Radha V. Jayaram,
Chandrashekhar V. Rode
Publication year - 2017
Publication title -
acs omega
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.779
H-Index - 40
ISSN - 2470-1343
DOI - 10.1021/acsomega.7b00201
Subject(s) - catalysis , phosphotungstic acid , domino , chemistry , hydroquinone , oxidative coupling of methane , ferric , oxidative phosphorylation , combinatorial chemistry , organic chemistry , photochemistry , biochemistry
A domino synthesis of 3-indolylquinones was achieved successfully via direct oxidative C-C coupling of hydroquinones with indoles over Ag 2 O and Fe 3 O 4 /povidone-phosphotungstic acid (PVP-PWA) catalysts using H 2 O 2 in tetrahydrofuran at room temperature. Ag 2 O catalyzed the in situ oxidation of hydroquinone and 3-indolylhydroquinone intermediates, whereas ferrite solid acid, Fe 3 O 4 /PVP-PWA, with a 1:4:1 ratio of Fe 3 O 4 , 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 (81-97%) of 3-indolylquinones. Fe 3 O 4 /PVP-PWA was separated magnetically, whereas simple filtration could separate Ag 2 O, both of which could be recycled several times without losing their activities.
Accelerating Research
Robert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom
Address
John Eccles HouseRobert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom