Eine neue strategie zur synthese partiell fluorierter 1,3-azole

Poly(aryl ether thiazole)s with Pendent Trifluoromethyl Groups

“…As can be expected, the incorporation of a m-phenylene ring into the polymer backbone in place of a p-phenylene ring decreases the glass transition temperature by [26][27][28][29][30] deg. This is due to the additional rotational degree of freedom, caused by the additional bend in the repeating unit. "…”

“…The resulting poly(aryl ether thiazole)s are amorphous with glass transition temperatures between 169 and 217 °C, depending on the exact structure of the repeating unit. The additional angle which is introduced by replacement of the p-phenylene ring in polymers 9 with a zn-phenylene ring in polymers 10 decreases Tg by [26][27][28][29][30] deg. A comparison with poly(aryl ether oxazole)s having similar structures reveals the effect of the thiazole ring on glass transition temperature, solubility, and thermal stability.…”

“…Heteroaromatic polymers are well-known for their excellent thermooxidative stability in combination with good mechanical properties.1 A large number of different heteroaromatic structures has already been incorporated into polymers. Rossbach and Oberlein2 mention polymers based on over 30 different heteroaromatic systems in their review. Among the more popular examples for these structures are benzoxazoles,3-5 ben-zothiazoles, [6][7] benzimidazoles,8-9 oxadiazoles, [10][11][12] pyrazoles,13 quinoxalines,14,15 six-membered nitrogen heteroaromatics, [16][17][18] and some ladder-type structures such as benzimidazobenzoisoquinoline (BBL) and derivatives.…”

Synthesis and properties of polyfluorinated oxazoles

“…5 A number of methods for the preparation of 2 aryl and 2 heteroaryl substituted fluorinated oxazoles are based on transformations of acylimines of hexa fluoroacetone. [6][7][8] Fully fluorinated oxazoles have never been prepared by these methods; only N methyl N perfluoroacyl 2 aminoperfluoropropenes are formed from perfluoro acylimines of hexafluoroacetone. 9 The present work con tinues the study of the routes to polyfluorinated oxazoles and gives an account of their properties.…”

Zum Cycloadditionsverhalten von bis(trifluormethyl)substituierten Nitril-yliden [1]. Positionsselektivität und Regiochemie bei Abfangreaktionen mit Heterokumulenen / Cycloaddition Behaviour of Bis(trifluoromethyl) Substituted Nitrile Ylides [1]. Site Selectivity and Regiochemistry of Trapping Reactions with Heterocumulenes

“…Die Strukturzuordnung im Sinne von Formel 8 basiert auf einem Spektrenvergleich mit auf anderem Wege synthetisierten 5-Fluor-4-trifluormethyl-1.3-azolen 9a-c [20]. Die Bildungsweise der Verbindungen 8, die auch in den Rohprodukten der Verbindungen 4b-4d (R = Aryl) 19 F-NMR-spektroskopisch nachgewiesen werden können, ist noch nicht geklärt.…”