4H-1,3-Oxazines (3) and/or 4,5-dihydro-oxazoles (9,10) and thiaanalogues are formed on reaction of alk-1-ynes with the 4,4-bis(trifluoromethyl)-1-oxa-3-azabuta-1,3-dienes (1) and 1-thia-3-azabuta-1,3-dienes (4), respectively.
Über eine neue Methode zur positionsselektiven Einführung von Trifluormethyl-Gruppen in Heteroaromaten, Teil<sup>1</sup>. Synthese von trifluormethyl-substituierten 1,3-Azolen (Oxazole, Thiazole, Imidazole)
作者:Klaus Burger、Klaus Geith、Dieter Hübl
DOI:10.1055/s-1988-27509
日期:——
A New Method for Regioselective Introduction of Trifluoromethyl Groups into Heteroarenes; Part 1. Synthesis of Trifluoromethyl-substituted 1,3-Azoles (Oxazoles, Thiazoles, Imidazoles) The reaction of 4,4-bis(trifluoromethyl) -substituted hetero-1,3-dienes [N-(Hexafluoro-2-propylidene)carboxamides, -thiocarboxamides, and -amidines] with tin(II) chloride affords 5-fluoro-4-trifluoromethyl- oxazoles, -thiazoles, and -imidazoles, respectively. The reaction sequence involves heterocyclic tin(IV) compounds as intermediates.