Early Examples of Chemical Reactions in SCFs

Early research on hydrothermal reactions was also carried out by Charles Friedel, an instructor at the Ecole Normale Supdrieure [108], the same institution where Paul Villard received his education. Over many years Charles, and later his son Georges Friedel, published a series of papers on the reaction of minerals in H2O at temperatures and presumably also pressures far above critical, starting with the preparation of quartz in 1879 [109,110]. Charles Friedel is more famous for his discovery of the Friedel-Crafts alkylation of aromatics. The works of de LaTour, Daubr6e and the Friedels together ensured that the first experimental reactions of and in SCFs were those of H2O, as reviewed in great detail by Morey [111]. 

Several other chemists were active in the field of supercritical fluid reactions at the beginning of the twentieth century. For example, Briner studied the decomposition and reactivity of supercritical fluids such as scNO and scCO (e.g., eq 1.1-6) [119-122]. He also investigated the system N2-H2 and reported that N2 and H2 do not combine at room temperature and 900 bar [122]. At the Chemical Institute of the University of Berlin, Arthur Stabler studied the reactions of alkyl halides such as chloroethane with SCNH3 (eq 1.1-7) [123]. One of the earliest attempts to utilize SCFs for the selective synAesis of low molecular weight organic products dates to the early 1940s, when Patat at the University of Innsbruck studied the hydrolysis of aniline under supercritical conditions (eq 1.1-8) [124]. 

There are many more reports and patents of reactions in SCFs than the selected examples mentioned here, especially in the period 1910-1945. Since 1945, the literature has become so extensive that it is not possible to review 

---