High pressure nucleophilic fluoride-ion substitution reactions: Formation of fluoroalkylbenzenes

Article abstract of DOI:10.1016/0022-1139(96)03417-3

A series of 1-phenyl-2-tosyloxy- and 1-phenyl-3-tosyloxyalkanes was synthesized and then subjected to tetrabutylammonium fluoride in THF under 15 kbar (1.5 GPa), 8 kbar or 1 bar pressures. The resultant substitution and elimination reaction product distributions were analyzed. The application of pressure enhanced the progress of the fluoride-ion substitution reactions. The degree of selectivity of the one reaction over the other was found to be a function of tosylate substrate structure and the amount of pressure applied. The exclusive formation of fluoroalkanes from 1-phenyl-2-tosyloxyalkane substrates under 15 kbar pressure demonstrated the potential of the pressure method for prospective use in fluorine-18 radiolabelling applications.