A Versatile Domino Synthesis Affording Novel S- and U-Shaped Terpyridines. - Synthesis, Properties and Crystal Structure

Autor:	Ulrich Flörke, Ralf Keuper, Hans-Jürgen Haupt, Nikolaus Risch
Rok vydání:	2006
Předmět:	Reaction mechanism General method Cascade reaction Chemistry Organic Chemistry Iminium General Chemistry Nuclear magnetic resonance spectroscopy Crystal structure Physical and Theoretical Chemistry Ternary operation Combinatorial chemistry Domino
Zdroj:	Liebigs Annalen. 1996:705-715
ISSN:	1099-0690 0947-3440
Popis:	The development of a simple and general method for the preparation of multifunctional terpyridines is described. The treatment of the ketones 1a–g with ternary iminium salts results in the formation of the isomeric terpyridines 6 and 8 (according to a domino reaction). A possible reaction mechanism is discussed. In some cases the isolation of the postulated dihydropyridine intermediates was successful. The isolation of the 1,4-dihydropyridines 5e, 5j, and 5r (donor-substituted) is surprising, because most of the stable dihydropyridines are acceptor-substituted. In several cases the yields of such domino reactions are very high (>80%). Whether Sor U-shaped terpyridines are formed is immediately recognized by NMR spectroscopy. Some special cases (8c, 8e, 6h) were investigated by means of single-crystal X-ray analysis.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::04a442bcec4a503478e2bad17117d00e https://doi.org/10.1002/jlac.199619960511 Zobrazit plný text záznamu Plný text