Ammonia and chiral systems

Ammonia and Chiral Systems Four Electrons in Larger Systems Mote Than Eour Electrons... 

Applications of sodio- and potassio-organophosphide reagents also continue to appear. A mixed sodio-potassio-diphenylphosphide has been used in the synthesis of the chiral systems (69). Interest has also continued in exploring SrnI processes involving metallophosphide reagents in liquid ammonia, some of which are... 

In a different approach a super-high-throughput ee-assay was developed on the basis of chirally modified capillary array electrophoresis (CAE).90 CAE was used in the Human Genome Project, and commercially available instruments have been developed which comprise a high number of capillaries in parallel, for example the 96-capillary unit MegaBACE consisting of 6 bundles of 16 capillaries.91 The system can address a 96-well microtiter plate. It was adapted to perform ee-determinations of chiral amines, which are potentially accessible by catalytic reductive amination of ketones, transition metal catalyzed Markovnikov addition of ammonia, or enzymatic hydrolysis of acetamides (Scheme 14).90... 

Ito et al. described the first application of pH-zone refining to chiral separation using A -dodecanoyl-L-proline-3,5-dimethylanilide as CS (40 mM) in the separation of DNB-( )-Leu enantiomers [59]. A binary solvent system composed by a mixture of MTBE-water has been used. Due to the acidic character of the analyte, ttifluo-roacetic acid was added as a retainer agent to the organic MTBE stationary phase and ammonia was added to the aqueous mobile phase as a displacer agent. In the described conditions the separation of 2 g of leucine racemate (CS/racemate molar ratio 1.30) in a single run was possible in a CCC device of 330 mL. 

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