FLUORODEHYDROXYLATION, A NOVEL METHOD FOR SYNTHESIS OF FLUOROAMINES AND FLUOROAMINO ACIDS

The alcoholic hydroxyl groups in hydroxyamines and hydroxyamino acids are selectively replaced by fluorine by reaction with sulfur tetrafluoride (SF4) in liquid hydrogen fluoride solution. In contrast to the traditional methodology of fluorination with SF4 (50-250 °C, in a high pressure reactor) this method, called fluorodehydroxylation. can usually be run at -78 °C and atmospheric pressure. This indicates a large increase in the reactivity of SF4. The mechanism of fluorodehydroxylation involves carbocation intermediates in some instances and SN2 mechanism in others, probably always proceeding via a ROSF3 intermediate. © 1979, American Chemical Society. All rights reserved.