AgOTf-catalyzed reaction of sulfonyl hydrazones with ynamides led to stereoselective synthesis of α-amino alkenyl-substituted hydrazone derivatives. Issue 39 (27th September 2019)

• Record Type: Journal Article
• Authors: Cao, Ziping; Yan, Shikun; Zhao, Changyin; Sun, Xuejun; Tian, Laijin; Meng, Xin
• Is Part Of: Tetrahedron. Volume 75:Issue 39(2019)
• Publication Date: 2019-09-27
• Subjects: Hydrazone -- Ynamide -- Enamide -- Silver catalysis -- Alkenylation; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tet.2019.130534
• Languages: English
• ISSNs: 0040-4020

Abstract

Abstract: A novel method for the synthesis of α -amino alkenyl-substituted hydrazone derivatives was disclosed through silver-catalyzed reaction of sulfonyl hydrazones with ynamides. The present method features mild conditions, high stereoselectivity and good yields. The proposed mechanism involves silver-mediated generation of a keteniminium ion intermediate to facilitate the stereoselective addition of hydrazones in the presence of K2 CO3, while pyrazole ring could not be constructed under the current conditions. Graphical abstract: Image 1 Highlights: Synthesis of α -amino alkenyl-substituted hydrazone derivatives was achieved in high efficiency. The reaction could proceed in a highly stereoselective manner. This work achieved the alkenylation of NH of hydrazones that was often ignored.