Reaction of perfluorinated nitriles with benz-and terephthalamidoximes for the isolation of mixed 1,2,4-oxadiazoles
摘要:
The reaction of perfluorinated nitriles with benz- and terephthalamidoximes afforded amidoximimidates which can form mixed 1,2,4-oxadiazoles in high yield under mild conditions by the action of acid fluorides of perfluorocarboxylic acids. The structure of the compounds obtained was confirmed by the methods of C-13, F-19, and H-1 NMR, and by IR spectroscopy.
New catalytically or highpressure activated reactions and routes, including coupling, double bond migration in allylic systems, and various types of cycloaddition and dihydroamination have been used for the synthesis of novel bithiophene derivatives. Thanks to the abovementioned reactions and routes combined with non-catalytic ones, newacetylene, butadiyne, isoxazole, 1,2,3-triazole, pyrrole, benzene
Synthesis of 3,5-Disubstituted Isoxazoles through a 1,3-Dipolar Cycloaddition Reaction between Alkynes and Nitrile Oxides Generated from <i>O</i>
-Silylated Hydroxamic Acids
by 1,3‐dipolar cycloaddition between alkynyl dipolarophiles and nitrile oxide dipoles generated in‐situ from O‐silylated hydroxamicacids in the presence of trifluoromethanesulfonic anhydride and NEt3. Thanks to the mild, metal‐free and oxidant‐free conditions that this strategy offers, the reaction was successfully applied to a wide variety of alkynyl dipolarophiles, demonstrating the tolerance of this
Terephthalonitrile di-N-oxide and isophthalonitrile di-N-oxide were synthesized from the corresponding hydroxamic chlorides by dehydrochlorination with triethylamine. Their chemical properties and the polycycloadditions with diolefins were examined. The polymers obtained were amorphous and their molecular weights were not so high. The thermal gravimetric analyses of them showed that the polymers were stable up to 300–350°C in air.
A class of relatively low molecular-weight oligomers containing at least one isoimide group and terminal groups capable of undergoing an addition polymerization reaction. The oligomers of the present invention are characterized by excellent solubility in common solvents and a melting temperature considerably lower than their cure temperature, thus enabling the oligomers to be formed into cured polymers more slowly and at lower temperatures, all without the evolution of deleterious gases.