Synlett

l-Proline-catalyzed asymmetric Michael addition of 2-oxindoles to enones: a convenient access to oxindoles with a quaternary stereocenter

MH Freund, SB Tsogoeva

Index: Freund, Matthias H.; Tsogoeva, Svetlana B. Synlett, 2011 , # 4 p. 503 - 507

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Citation Number: 17

Abstract

Abstract A new organocatalytic approach for 1, 4-conjugate addition of 2-oxindoles to α, β- unsaturated ketones using the combination of readily available and nonexpensive l-proline and achiral trans-2, 5-dimethylpiperazine as catalytic system is provided. The reaction results in oxindole derivatives with vicinal quaternary and tertiary carbon centers in up to 99% yield and 91% ee.