THE PREPARATION OF FLUOROARENES BY THE CATALYTIC DECARBOXYLATION OF ARYL FLUOROFORMATES

Article abstract of DOI:10.1016/S0022-1139(00)81306-8

The catalytic decarboxylation of phenyl fluoroformate to fluorobenzene has been achieved with yields of 70-80percent in a flow system using alumina or alumina-based catalysts.The reaction occurs in short space times (<1 s) and with optimal efficiency at ca. 300 deg C (some 500 deg C lower than the temperature required for the thermal decomposition of the fluoroformate).Impregnation of the alumina with a platinum group metal gave the following order of catalytic activity: Pt/Al2O3>Pd/Al2O3>Rh/Al2O3 ca.Al2O3. 2,4,6-Trimethylphenyl fluoroformate, a new material, was found to decarboxylate similarly to give 1-fluoro-2,4,6-trimethylbenzene, but 4-chlorophenyl fluoroformate was noted to produce only low yields (ca. 10percent) of the corresponding aryl fluoride.