Asymmetric alkylation of 3-substituted benzofuran-2(3H)-ones

An enantioselective alkylation reaction of 3-substituted benzofuran-2(3H)-ones catalyzed by a chiral biscinchona alkaloid catalyst combined with TsOH·H2O was developed. The corresponding products, containing all carbon quaternary centers at the C3-positions of the benzofuran-2-ones, were obtained in moderate to good yields (up to 89%) with good enantioselectivities (up to 83% ee).

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