Asymmetric Synthesis of Spiropyrazolones by Sequential Organo‐ and Silver Catalysis. (16th December 2015)

• Record Type: Journal Article
• Authors: Hack, Daniel; Dürr, Alexander B.; Deckers, Kristina; Chauhan, Pankaj; Seling, Nico; Rübenach, Lukas; Mertens, Lucas; Raabe, Gerhard; Schoenebeck, Franziska; Enders, Dieter
• Is Part Of: Angewandte Chemie. Volume 128:Number 5(2016)
• Page Start: 1829
• Page End: 1832
• Publication Date: 2015-12-16
• Subjects: Asymmetrische Synthesen -- Conia-En-Reaktion -- Organokatalyse -- Pyrazolone -- Silber-Katalyse; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201510602
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: A stereoselective one‐pot synthesis of spiropyrazolones through an organocatalytic asymmetric Michael addition and a formal Conia‐ene reaction has been developed. Depending on the nitroalkene, the 5‐exo‐dig‐cyclization could be achieved by silver‐catalyzed alkyne activation or by oxidation of the intermediate enolate. The mechanistic pathways have been investigated using computational chemistry and mechanistic experiments.