Enantioselective Pictet-Spengler reactions of isatins for the synthesis of spiroindolones

TETRAHEDRON LETTERS

卷:52

Article

Badillo, Joseph J.¹  Silva-Garcia, Abel¹  Shupe, Benjamin H.¹  Fettinger, James C.¹  Franz, Annaliese K.¹ 

[1] Univ Calif Davis, Dept Chem, Davis, CA 95616 USA

关键词: Isatin;    Pictet-Spengler;    Chiral Brensted acid catalysis;    Spirooxindole;   

DOI  :  10.1016/j.tetlet.2011.08.071

来源: Elsevier

【 摘 要 】

The condensation cyclization between isatins and 5-methoxy tryptamine catalyzed by chiral phosphoric acids provides spirooxindole tetrahydro-beta-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. (C) 2011 Elsevier Ltd. All rights reserved.

【 授权许可】

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