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RESEARCH PRODUCT
Intermolecular oxidative dehydrogenative 3,3′-coupling of benzo[b]furans and benzo[b]thiophenes promoted by DDQ/H+: total synthesis of shandougenine B
Heikki M. TuononenMikko MuuronenTom WirtanenJuho HelajaMartin NiegerJuha Hurmalainensubject
116 Chemical sciencesEFFICIENTfree radicalscoupling reactionsvapaat radikaalit010402 general chemistryPhotochemistry01 natural sciencesMedicinal chemistryCoupling reactionoxidative dehydrogenationC BOND FORMATIONSCHOLL REACTIONELECTRON-TRANSFERMolecular orbitalReactivity (chemistry)luonnonaineiden synteesiDIPHOSPHINE LIGANDSta116BASIS-SETSCATALYZED STEREOSELECTIVE REACTIONS010405 organic chemistryChemistryOrganic ChemistrykytkentäreaktiotSubstrate (chemistry)Total synthesishapettava dehydroganaatiolaskennallinen kemiaCharge-transfer complex0104 chemical sciencesRadical ionsynthesis of natural productsACIDElectrophileCATION-RADICALSHETEROCYCLESdescription
With an excess of a strong acid, 2,3-dichloro-5,6-dicyano-1,4-quinone (DDQ) is shown to promote metal-free intermolecular oxidative dehydrogenative (ODH) 3,3'-coupling of 2-aryl-benzo[b]furans and 2-aryl-benzo[b]thiophenes up to 92% yield as demonstrated with 9 substrates. Based on the analysis of oxidation potentials and molecular orbitals combined with EPR, NMR and UV-Vis observations, the studied reaction is initiated by a DDQ-substrate charge transfer complex and presumably proceeds via oxidation of the substrate into an electrophilic radical cation that further reacts with another molecule of a neutral substrate. The coupling reactivity can easily be predicted from the oxidation potential of the substrate and the morphology of its frontier molecular orbitals. The intermolecular ODH coupling reaction allowed a concise total synthesis of the natural product shandougenine B. Peer reviewed
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2016-01-01 | Organic Chemistry Frontiers |