Perfluorocarbons product developments

For many years, the perfluorocarbons seemed to present insurmountable hurdles to further development. However, newer emulsions are being developed that allow higher concentrations of dissolved oxygen and interest in perfluorocarbon products has been renewed (31). One product, Fluosol-DA, a 20% by weight emulsion, has been licensed for use in coronary angioplasty. As of 1991, this product was available through the U.S. Food and Drug Administration (FDA) for compassionate use. 

The first successful development of an injectable perfluorocarbon-based commercial product was achieved by the Green Cross Corporation in Japan, when it made Fluosol-DA , a dilute (20 /o w/v) emulsion based on perfluorodecalin and perflurotripropylamine emulsified... 

A carbon atom can be bonded to as many as four halogen atoms, so an enormous number of organic halides can exist. Completely fluorinated compounds are known as fluorocarbons or sometimes perfluorocarbons. The fluorocarbons are even less reactive than hydrocarbons. Saturated compounds in which all H atoms have been replaced by some combination of Cl and F atoms are called chlorofluorocarbons or sometimes freons. These compounds were widely used as refrigerants and as propellants in aerosol cans. However, the release of chlorofluorocarbons into the atmosphere has been shown to be quite damaging to the earth s ozone layer. Since January 1978, the use of chlorofluorocarbons in aerosol cans in the United States has been banned, and efforts to develop both controls for existing chlorofluorocarbons and suitable replacements continue. The production and sale of freons have been banned in many countries. 

An exciting recent development in this field is the application of the unusual solubility properties of perfluorocarbons as solvents in so-called fluorous biphase chemistry [7]. These novel synthetic procedures enable ready separation of suitably designed catalysts and reagents by simple phase separation of many hydrocarbon solvents (containing the product) from the fluorous phase containing the catalyst. Success in these procedures is of course contingent on the inert nature of the fluorous phase under the reaction conditions. 

Carbonyl compounds are more polar than olefins and therefore much less soluble in perfluorocarbons, so the aldehyde products were expelled from the fluorous phase and efficiently taken up in the organic phase. Most catalytic FBS reactions developed to date likewise have involved substrates of low polarity that are converted to more polar products. Some exceptions to this rule of thumb are known, however, as exempli lied by an efficient FBS process for the esterification of equimolar amounts of an alcohol and a carboxylic acid [7]. 

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