'Atypical Ugi' tetrazoles. Issue 12 (17th January 2020)

• Record Type: Journal Article
• Authors: Abdelraheem, Eman M. M.; Goodwin, Imogen; Shaabani, Shabnam; de Haan, Michel P.; Kurpiewska, Katarzyna; Kalinowska-Tłuścik, Justyna; Dömling, Alexander
• Is Part Of: Chemical communications. Volume 56:Issue 12(2020)
• Page Start: 1799
• Page End: 1802
• Publication Date: 2020-01-17
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1039/c9cc09194g
• Languages: English
• ISSNs: 1359-7345

Abstract

Abstract : We surprisingly found that combining the substrates of Ugi tetrazole reaction gives two different constitutional isomeric Ugi products A and B. A is the expected classical Ugi products whereas B is an isomeric product ('atypical Ugi'). Abstract : Amino acid-derived isocyano amides together with TMSN3, oxocomponents and 1° or 2° amines are common substrates in the Ugi tetrazole reaction. We surprisingly found that combining these substrates gives two different constitutional isomeric Ugi products A and B. A is the expected classical Ugi product whereas B is an isomeric product ('atypical Ugi') of the same molecular weight with the tetrazole heterocycle migrated to a different position. We synthesized, separated and characterized 22 different isomorphic examples of the two constitutional isomers of the Ugi reaction to unambiguously prove the formation of A and B. Mechanistic studies resulted in a proposed mechanism for the concomitant formation of A and B.