Selective Vinylogous Aldol Reactions of β‐Methyl‐Substituted Cyclic Enones with Isatins Catalyzed by DBU and Pyrrolidine to Afford 3‐Substituted 3‐Hydroxyoxindoles
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Open Access
- 14 June 2023
- journal article
- research article
- Published by Wiley in Asian Journal of Organic Chemistry
- Vol. 12 (8)
Abstract
The development of regioselective aldol reactions of β‐methyl‐substituted cyclic enone derivatives with isatins to afford the aldol products with the bond formation at the methyl group of the β‐methyl‐substituted cyclic enone derivatives is described. Catalyst systems composed of DBU and pyrrolidine with DMSO were identified that resulted in the aldol reactions with almost perfect regioselectivities. DBU, pyrrolidine, and DMSO were all required to selectively afford the γ‐position‐reacted aldol products. With the use of this method, the scope of the 3‐substituted 3‐hydroxyoxindole derivatives that can be concisely synthesized was expanded.Keywords
Funding Information
- Okinawa Institute of Science and Technology Graduate University
This publication has 38 references indexed in Scilit:
- Total Synthesis of Oxidized Welwitindolinones and (−)-N-Methylwelwitindolinone C IsonitrileJournal of the American Chemical Society, 2011
- Dioxindole in Asymmetric Catalytic Synthesis: Routes to Enantioenriched 3‐Substituted 3‐Hydroxyoxindoles and the Preparation of Maremycin AAngewandte Chemie International Edition, 2011
- Total Synthesis ofN-Methylwelwitindolinone D IsonitrileJournal of the American Chemical Society, 2011
- Catalytic Asymmetric Addition of Alkyl Enol Ethers to 1,2‐Dicarbonyl Compounds: Highly Enantioselective Synthesis of Substituted 3‐Alkyl‐3‐HydroxyoxindolesAngewandte Chemie International Edition, 2011
- Quinidine Thiourea‐Catalyzed Aldol Reaction of Unactivated Ketones: Highly Enantioselective Synthesis of 3‐Alkyl‐3‐hydroxyindolin‐2‐onesAngewandte Chemie International Edition, 2010
- Organocatalytic Asymmetric Synthesis of Substituted 3-Hydroxy-2-oxindoles via Morita−Baylis−Hillman ReactionJournal of the American Chemical Society, 2010
- Asymmetric Aldol Reaction of Acetaldehyde and Isatin Derivatives for the Total Syntheses of ent-Convolutamydine E and CPC-1 and a Half Fragment of Madindoline A and BOrganic Letters, 2009
- Enantiospecific Total Synthesis of the Hapalindoles, Fischerindoles, and Welwitindolinonesviaa Redox Economic ApproachJournal of the American Chemical Society, 2008
- Lewis Acid-Catalyzed Enantioselective Hydroxylation Reactions of Oxindoles and β-Keto Esters Using DBFOX LigandJournal of the American Chemical Society, 2006
- Conceptually New Directed Aldol Condensation Using Aluminum Tris(2,6-diphenylphenoxide)Journal of the American Chemical Society, 1998