Valine, hydrogenation modifier

This finding was also supported by the following phenomena. That is, the hydrogenation rates of various esters of acetoacetic acid over RNi modified with valine (Val-MRNi) were found to have a good correlation with the molecular volume of the ester as shown in Table X (34). 

Analytical Properties Separation of amino acid enantiomers most effective of the L-valine urea derivatives depends on hydrogen bond interactions usually prepared on LiChro-sorb (10 pm) hexane plus isopropanol modifier has been used as the liquid phase Reference 4... 

In addition to this we have several examples of which the polymer conformation of the polymeric complex leads the asymmetrical selectivity Hydrogenation reactions of 1-methylcinnamic acid and 1-acetamidocinnamic acid by several poly(L-amino acid)-Pd complexes are observed (142-144). Poly(L-valine) (/3-form) and poly(/3-benzyl-L-aspartate) (a-helix, sinistral) give dextrorotative products, and poly(L-leucine) and poly( 3-benzyl-L-aspartate) (a-helix, dextral) do levo-rotatory products. Also, optical active poly-/3-hydroxyl esters-Raney Ni catalyst (145) and Ion-exchange resin modified by optical active amino acid-metal complex (146,147) are observed in asymmetrically selective hydrogenations. 

This structure was modified by replacing one of the hydrogens on each of the NH2 groups. The most potent inhibitor in this series had both hydrogens replaced by cbz—Val (Structure 4.6), the amino acid valine protected by a protecting group whose trivial name is carbobenzoxy. 

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