Abstract: A method for selecting at least one catalyst from a catalyst library on the basis of the reactivity thereof in a chemical conversion process includes: (a) testing the catalytic activity of a first catalyst from said catalyst library with respect to a reaction medium containing, as the compounds to be converted, at least one reactivity probe having a labeling system and including at least one reaction unit capable of reacting in said chemical conversion; (b) analyzing the reaction medium after said catalytic test for the purpose of qualitatively and/or qualitatively characterizing the resulting compounds; (c) repeating steps (a) and (b) for at least one other catalyst in said library; and (d) comparing the analysis results for each catalyst in order to characterize at least one catalyst having the required reactivity in said chemical conversion.

Abstract: The invention concerns a method for preparing 4-hydroxyisoleucine diastereoisomers and enantiomers and derivatives thereof of general formula (I), characterized in that it consists in reducing an isoxazole derivative of formula (II) in conditions directly resulting in the derivatives of formula (I), or in obtaining at least a lactone of structure (III) in racemic form(s), or a enantiomerically enriched mixture, followed by opening, in basic conditions, in an aprotic or protic solvent, the desired lactone(s) and, optionally, separating the desired form. The invention is useful for preparing in particular (2S, 3R, 4S)-4-hydroxyisoleucine.

Abstract: The invention relates to a method for the synthesis of two isomers, at function OH, alone or in mixtures, of amino acids ? or the derivatives thereof, having general formula (B), wherein: linkage C—O of the 4-position carbon (represented by symbol) denotes one or other of isomers III or IV, or mixtures thereof. Moreover, R1 and R2 represent: a hydrogen atom; or either R1 or R2 represents a hydrogen atom and the other substituent is a radical Ra, an acyl group —CORa, such as acetyl, or a functional group —COORa, —SO2Ra, —N (Ra, Rb), Ra and Rb, which are identical or different, representing a C1-C12 linear or branched alkyl radical, optionally substituted, an aryl group with one or more aromatic rings and heterocycles, comprising between 5 and 8C, optionally substituted, or aralkyl, the alkyl substituent and the aryl group being as defined above; or R1 and R2 both represent a substituent as defined above. R3 represents a hydrogen atom or Ra and R4 has the significance of Ra.

Abstract: A method for selecting at least one catalyst from a catalyst library on the basis of the reactivity thereof in a chemical conversion process includes: (a) testing the catalytic activity of a first catalyst from said catalyst library with respect to a reaction medium containing, as the compounds to be converted, at least one reactivity probe having a labeling system and including at least one reaction unit capable of reacting in said chemical conversion; (b) analyzing the reaction medium after said catalytic test for the purpose of qualitatively and/or qualitatively characterizing the resulting compounds; (c) repeating steps (a) and (b) for at least one other catalyst in said library; and (d) comparing the analysis results for each catalyst in order to characterize at least one catalyst having the required reactivity in said chemical conversion.

Abstract: The invention relates to a method for creating a database enabling, in particular, the selection of at least one reaction-capable catalyst, comprising the following steps: a) preparing a number of different reaction media containing the same reactivity probe and each having at least one catalyst; b) analyzing, by means of an analytic method, each reaction medium after reaction, and; c) assigning, in the database, an analysis result according to step b) to the reactivity probe, this result characterizing different reaction products obtained from said reactivity probe.

Abstract: The invention relates to a method for the synthesis of two isomers, at function OH, alone or in mixtures, of amino acids ? or the derivatives thereof, having general formula (B), wherein: linkage C—O of the 4-position carbon (represented by symbol) denotes one or other of isomers III or IV, or mixtures thereof. Moreover, R1 and R2 represent: a hydrogen atom; or either R1 or R2 represents a hydrogen atom and the other substituent is a radical Ra, an acyl group —CORa, such as acetyl, or a functional group —COORa, —SO2Ra, —N (Ra, Rb), Ra and Rb, which are identical or different, representing a C1-C12 linear or branched alkyl radical, optionally substituted, an aryl group with one or more aromatic rings and heterocycles, comprising between 5 and 8C, optionally substituted, or aralkyl, the alkyl substituent and the aryl group being as defined above; or R1 and R2 both represent a substituent as defined above. R3 represents a hydrogen atom or Ra and R4 has the significance of Ra.

Abstract: The invention concerns a method for preparing 4-hydroxyisoleucine diastereoisomers and enantiomers and derivatives thereof of general formula (I), characterized in that it consists in reducing an isoxazole derivative of formula (II) in conditions directly resulting in the derivatives of formula (I), or in obtaining at least a lactone of structure (III) in racemic form(s), or a enantiomerically enriched mixture, followed by opening, in basic conditions, in an aprotic or protic solvent, the desired lactone(s) and, optionally, separating the desired form.