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Enantioselective Pictet-Spengler Reactions of Isatins for the Synthesis of Spiroindolones.

ABSTRACT: The condensation cyclization between isatins and 5-methoxy tryptamine catalyzed by chiral phosphoric acids provides spirooxindole tetrahydro-?-carboline products in excellent yields (up to 99%) and enantioselectivity (up to 98:2 er). A comparison of catalysts provides insight for the substrate scope and factors responsible for efficient catalytic activity and selectivity in the spirocyclization. Chiral phosphoric acids with different 3,3'-substitution on the binaphthyl system and opposite axial chirality afford the spiroindolone product with the same absolute configuration.

SUBMITTER: Badillo JJ

PROVIDER: S-EPMC3307811 | biostudies-literature | 2011 Oct

REPOSITORIES: biostudies-literature

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Enantioselective Pictet-Spengler Reactions of Isatins for the Synthesis of Spiroindolones.

Badillo Joseph J JJ Silva-García Abel A Shupe Benjamin H BH Fettinger James C JC Franz Annaliese K AK

Tetrahedron letters 20111001 43

The condensation cyclization between isatins and 5-methoxy tryptamine catalyzed by chiral phosphoric acids provides spirooxindole tetrahydro-β-carboline products in excellent yields (up to 99%) and enantioselectivity (up to 98:2 er). A comparison of catalysts provides insight for the substrate scope and factors responsible for efficient catalytic activity and selectivity in the spirocyclization. Chiral phosphoric acids with different 3,3'-substitution on the binaphthyl system and opposite axial ...[more]

PMID: 22442499

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