Hydrogen Fluoride Catalysis

Abstract

Publisher Summary Hydrogen fluoride as a catalyst for organic chemical reactions has many and widely diverse uses. It is used for many different reactions over a wide range of conditions and with many different kinds of reactants. Where it is useful, it is a preferred catalyst because of its advantages. Hydrogen fluoride as a catalyst for organic chemical reactions has certain disadvantages in the small laboratory or where a small quantity of product of not too high purity is desired. It requires the use of a fume hood, metal containers and reaction vessels, and a technique different from the usual preparations that can be done in glass. Hydrogen fluoride is particularly powerless as a cracking and tarring agent of hydrocarbons so strikingly found with Friedel Crafts reaction using aluminum chloride or similar agents. Hydrogen fluoride has no oxidizing power and so cannot undergo a reaction similar to sulf onation as experienced with sulfuric acid in the formation of acid sludges. The elimination of such side reactions combined with the ease of removal of the agent makes for higher yields of purer products. As hydrogen fluoride functions with equal ease in alkylation with olefins, alkyl halides, or alcohols, and in acylation with acids, acid anhydrides as well as acyl halides, a wide choice of reagents is possible and a separate operation of the reconversion of them is often saved.