NEW ANHYDROUS FLUORINATING SYSTEMS: THE COMBINATION OF CROWN-ETHERS AND CESIUM FLUORIDE. A RELATIVE RATE STUDY.

Article abstract of DOI:10.1016/S0040-4039(00)80576-6

New, anhydrous fluorinating systems are presented. 18-Crown-6 or dibenzo-24-crown-8 act as solid - liquid phase transfer catalysts with cesium fluoride.A catalytic amount of these crown ethers with CsF increased the rate of fluorodestannylation of trialkyltin mercaptides (used as a good fluoride probe) by a factor of 5-7.In addition, alkyl bromides, such as benzyl bromide, reacted in a similar way.Kinetic evidence for "sandwich" or "edge" complexes with the cesium cation and 18-crown-6 is presented.