Stereoselective Mannich Reaction of α‐Acetoxy‐β‐keto Esters with Isatin Imine: An Efficient Access to Vicinal Tetra‐Substituted Stereocenters. Issue 37 (1st October 2021)

• Record Type: Journal Article
• Authors: Kaur, Jasneet; Preet Kaur, Banni; Islam, Nasarul; Chauhan, Pankaj; Singh Chimni, Swapandeep
• Is Part Of: European journal of organic chemistry. Issue 37(2021)
• Page Start: 5193
• Page End: 5201
• Publication Date: 2021-10-01
• Subjects: α-Acetoxy-β-keto esters -- Asymmetric synthesis -- Isatin imine -- Mannich reaction -- Organocatalysis; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.202101047
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract: A highly diastereo‐ and enantioselective Mannich reaction of α ‐acetoxy‐ β ‐keto esters with isatin imine was developed. The quinine thiourea organocatalyst smoothly promoted the asymmetric Mannich reaction to furnish various 3‐substituted‐3‐aminooxindole derivatives bearing two adjacent tetra‐substituted stereocenters in up to 93 % yield, up to 98 % ee with >20 : 1 dr . The transition state structure and absolute configuration of the obtained product were predicted using DFT calculations, and results from single crystal X‐ray analysis are in agreement with the DFT studies. Abstract : Synthesis of optically active 3‐substituted‐3‐aminooxindoles containing vicinal quaternary stereogenic centers was achieved using a quinine thiourea organocatalyst. α ‐Acetoxy‐ β ‐keto esters have been introduced as nucleophiles to undergo Mannich reaction with isatin imines for asymmetric organocatalysis.