Herein it is shown, for the first time, that enolonium species are powerful electrophiles capable of reacting with aromatic compounds in an intermolecular manner to afford α-arylated ketones. The reaction is compatible with a variety of functional groups, is of wide scope with respect to aromatic compounds and ketone, and even works for polymerization-prone substrates such as substituted pyrroles, thiophenes, and furans. Only 1.6 to 5 equiv of the commodity aromatic substrates is needed.
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New Strategies for the Functionalization of Carbonyl Derivatives via α-Umpolung: From Enolates to Enolonium Ions.
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Institute of Organic Chemistry, University of Vienna, Währinger Straße 38, 1090 Vienna, Austria.
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2-Nitrocyclopropanes bearing ketones, amides, esters, and carboxylic acids in the 1 position may be accessed as single diastereoisomers in one operation from the corresponding unsaturated carbonyl compounds. The source of the nitro-methylene component is nitromethane. The reaction proceeds at room temperature under mild conditions.
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