A new and practical synthesis of octafluoro[2.2]paracyclophane

An important aspect of any method for (2, 2) paracyclophane synthesis is the necessity to carry out the reaction under high dilution conditions. The high dilution conditions are designed to provide the optimal kinetic environment for allowing unimolecular cyclization of 3 to compete effectively with bimolecular oligomerization. Consistent with this latter possibility is the fact that the two best cosolvents with THF have been found to be DMSO and HMPA, both recognized to be excellent facilitators of SET reactions. The truth is, though, that the emphasis in this work has been development of a good synthesis, with little effort of a mechanistic nature having been made. The new method uses a unique approach to circumvent the need for conventional high dilution technology. It allows one to add in most of the ingredients together rather quickly, while maintaining the necessary low concentration of monomer via control of its rate of in situ generation. © 1997 American Chemical Society.