ABSTRACT
Enantioselective reactions employing catalytic processes are a challenging problem for the organic chemist. In the pharmaceutical industry, much time and effort are being spent to develop practical techniques for efficient chiral synthesis, and asymmetric hydrogenation shows much promise in this application. A wide variety of apparatus can be used for chiral hydrogenations. Apparatus such as Schlenk-type glassware, conventional glass atmospheric vessels with gas burettes or hydrogen balloons, Parr shakers, stirred pressurized reactors, and Fischer-Porter bottles are used in many laboratories. At Abbott Laboratories we have constructed a dedicated homogeneous catalysis facility using Fischer-Porter bottles. The stereochemical characteristics of the ligand determine the results of the asymmetric reaction. Actually, only relatively few combinations of catalysts and substrates can give products in high optical yield, and such catalysts usually contain chelating diphosphine ligands.
