Multicomponent diversity and enzymatic enantioselectivity as a route towards both enantiomers of α-amino acids—a model study

A model study on a new, enantioconvergent method for the synthesis of chiral, nonracemic α-amino acids is presented. α-Acetoxyamides obtained in a Passerini multicomponent reaction are selectively hydrolyzed by Wheat Germ lipase. Studies on conversion of the thus obtained, enantiomerically enriched α-hydroxyamides into α-aminoamides are presented. Products of these reactions are then hydrolyzed to give α-amino acids.

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(S)-2-Hydroxy-N-(4-methoxy-benzyl)-3-phenyl-propionamideC17H19NO3[α]D25=-71.1 (c 1.0, chloroform)Chirality source: stereocontrolled synthesis from commercially available enantiopure compoundAbsolute configuration: (S)

Methanesulfonic acid (S)-1-(4-methoxy-benzylcarba-moyl)-2-phenyl-ethyl esterC18H21NO5S[α]D25=-66.0 (c 1.00, chloroform)Chirality source: stereocontrolled synthesis from commercially available enantiopure compoundAbsolute configuration: (S)

(R)-2-Azido-N-(4-methoxy-benzyl)-3-phenyl-propionamideC17H18N4O2[α]D25=-21.8 (c 1.00, chloroform)Chirality source: stereocontrolled synthesis from commercially available enantiopure compoundAbsolute configuration: (S)

(R)-PhenylalanineC9H11NO2[α]D25=-7.3 (c 1.00, acetic acid)Chirality source: stereocontrolled synthesis from commercially available enantiopure compoundAbsolute configuration: (S)

Toluene-4-sulfonic acid (S)-1-(4-methoxy-benzylcarbamoyl)-2-phenyl-ethyl esterC24H25NO5S[α]D25=-50.4 (c 1.0, chloroform)Chirality source: stereocontrolled synthesis from commercially available enantiopure compoundAbsolute configuration: (S)

Acetic acid (S)-1-(4-methoxy-benzylcarbamoyl)-2-phenyl-ethyl esterC19H21NO4[α]D25=-10.9 (c 1.0, chloroform)Chirality source: stereocontrolled synthesis from commercially available enantiopure compoundAbsolute configuration: (S)