Indoles to p-quinone

For the catalysis of addition of aryl nucleophiles, instead of indoles, to p-quinones, Li et al. had used In(OTf)3 as the catalyst and water instead of organic solvents [57]. Different quinones, including disubstituted ones, were reacted with benzene derivatives with electron-rich substituents to give good results. Preferences for 2,6-substituted products were reported for monosubstituted quinones, except when substituents are Lewis basic in nature, in which 2,5-substituted products were exclusively produced (Figure 8.31). 

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