Quaternization and dequaternization of pyrazoles in solvent-free conditions: Conventional heating<i>versus</i>microwave irradiation
作者:Enrique Díez-Barra、Antonio De La Hoz、Ana Sánchez-Migallón、José Elguero
DOI:10.1002/jhet.5570360410
日期:1999.7
We report a study on the quaternization and dequaternization of pyrazoles by conventional heating and microwave irradiation in solvent-freeconditions. Microwave irradiation produces an acceleration in the quaternization rate and a rapid equilibration between quaternized and non quaternized products. Dequaternization is also more rapid and a change on the selectivity is observed using symmetric pyrazolium
The efficient fixation of CO2 without co-catalyst and solvent under metal-free condition is still an urgent topic in sustainable chemistry. In this work, a series of dialkylpyrazolium ionicliquids are employed to promote the cycloaddition of CO2 and PO to produce PC. They would be easily synthesized by a simple one-pot reaction. The effect of alkyl chain length in cation and different anion is explored