Combining Organocatalysis and Photoredox Catalysis: An Asymmetric Synthesis of Chiral β‐Amino α‐Substituted Tryptamines. Issue 23 (21st August 2019)

• Record Type: Journal Article
• Authors: Levitre, Guillaume; Audubert, Clément; Dumoulin, Audrey; Goual, Nawel; Retailleau, Pascal; Moreau, Xavier; Masson, Géraldine
• Is Part Of: ChemCatChem. Volume 11:Issue 23(2019)
• Page Start: 5723
• Page End: 5727
• Publication Date: 2019-08-21
• Subjects: Asymmetric catalysis -- Photoredox Catalysis -- Chiral phosphoric acid -- Tryptamine -- Organocatalysis; Catalysis -- Periodicals; 541.39505
• DOI: 10.1002/cctc.201901266
• Languages: English
• ISSNs: 1867-3880

Abstract

Abstract: A stereoselective synthesis of functionalized β‐ amino α‐ substituted tryptamines has been achieved by a sequential asymmetric organocatalytic three‐component electrophilic amination and photocatalyzed Friedel‐Crafts reaction of indoles with moderate to high diastereoselectivities (up to >99 : 1 dr) and excellent enantioselectivities (up to >99 % ee ). We also demonstrated that the β ‐amino α ‐substituted tryptamines can be successfully engaged in a further catalytic step, furnishing various α, β ‐substituted tryptamines without erosion of enantioselectivity and with complete diastereoselectivity. Abstract : Out of the blue ! We report herein an enantioselective synthesis of highly functionalized β‐amino α‐substituted and α, β‐substituted tryptamines with high enantioselectivity (up to 99 % ee ) The process combines an enantioselective organocatalytic electrophilic amination of enecarbamates using dibenzylazodicarboxylate and thiol with a photocatalyzed Friedel‐Crafts reaction with indoles.