10017-09-1

The kinetics of oxidation of amino acids in aqueous medium were reinvestigated.The rate of oxidation follows second order with respect to chloramine-T (CAT) and an inverse dependence on (RNH2).At constant the rate of the reaction can be represented as (in the absence of chloride ion) .A linear relationship exists between pK1 and the rate constants.This shows the electrophilic attack of the oxidant at the carboxylato group of the amino acid.The effect of chloride ion on kobsd is catalytic.The mechanisms of the reactions are discussed in terms of the kinetic results.

Bromide-assisted electrochemical decarboxylation efficiently produces valuable nitriles in high yields from a wide range of naturally occurring amino acids in a single step. Bromide salts are used as both redox mediators and supporting electrolytes in a simple one-compartment setup. As demonstrated for lysine, the selectivity of the decarboxylation can be tuned towards nitriles, amines or amides. An electrochemical system is developed that allows the selective decarboxylation of a wide range of amino acids. Valuable nitriles are obtained in high yields in a single step by using bromide salts as both redox mediators and supporting electrolytes. The product selectivity of lysine can be tuned towards nitriles, amines, or amides.

Polyphenols, such as (+)-catechin and pyrogallol could be used to enhance stereochemical control in the lipase-catalyzed hydrolysis of alkynol benzoate esters, leading to increased enantioselectivities in the kinetic resolution of alkynols with lipase Amano AH.

Some title hydroxy compounds were resolved efficiently by complexation with the host compounds derived from tartaric acid.