Specific synthesis of N-fluoro-compounds using perfluorofluoroxy-reagents

Abstract

Secondary sulphonamides react with perfluorofluoroxy-compounds to give N-fluoro-derivatives in high yields. With secondary carboxamides the initially formed N-fluoroamides react further with cleavage of the amide bond and formation of NN-difluoroamines. An aromatic ring that is not deactivated towards electrophilic attack reacts in preference to an amide. Conversion of amides into the more reactive imino-ethers overcomes this problem. This is illustrated by the synthesis of the NN-difluoro-derivatives of amphetamine and tyramine. Evidence is presented for the mechanism of these reactions.