QUANTITATIVE MONOFLUORINATION BY PHENYLTETRAFLUOROPHOSPHORANE - INFLUENCE OF TEMPERATURE

The monofluorination by substitution of the hydroxyl group of the β-hydroxyesters of (o, m, p) Z - C6H4 - C(OH)R - CH R′ - COOR″ structure (where Z = halogen, methyl, methoxy, nitro and H) of 2,2,2 trichloroarylcarbinols by the phenyl tetrafluorophosphorane is described. The temperature at which the alkoxytrifluorophosphorane is decomposed, determines the nature (alkene alkoxytrifluorophosphorane, monofluorinated compounds) of the products and their yield. Knowledge of this temperature for erythro and threo isomers permits the selective fluorination of one them in a mixture. © 1979.