Oxidative Asymmetric Aza‐Friedel–Crafts Alkylation of Indoles with 3‐Indolinone‐2‐carboxylates Catalyzed by a BINOL Phosphoric Acid and Promoted by DDQ |
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Authors: | Suresh Yarlagadda Dr B Sridhar Dr Basireddy Venkata Subba?Reddy |
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Institution: | 1. Centre for Semiochemicals, CSIR-Indian Institute of Chemical Technology, Hyderabad, India;2. Laboratory of X-ray Crystallography, CSIR-Indian Institute of Chemical Technology, Hyderabad, India |
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Abstract: | An asymmetric aza‐Friedel–Crafts alkylation reaction between indoles and indolenines that were derived in situ from 3‐indolinone‐2‐carboxylates has been developed by using 3,3′‐bis(triphenylsilyl)‐1,1′‐binaphthyl‐2,2′‐diyl hydrogen phosphate as a catalyst. The reaction proceeded under mild conditions and provided chiral indol‐3‐yl‐3‐indolinone‐2‐carboxylate derivatives in good yields with excellent ee values (up to 98.6 %). Similarly, the Mannich‐type addition of indoline‐3‐ones to indolenines provided heterodimers with vicinal chiral quaternary centers. This method was successfully applied to the construction of the core structure of trigonoliimine C. |
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Keywords: | alkylation asymmetric synthesis indoles Mannich reaction synthetic methods |
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