Candida antarctica Lipase-Catalyzed Doubly Enantioselective Aminolysis Reactions. Chemoenzymatic Synthesis of 3-Hydroxypyrrolidines and 4-(Silyloxy)-2-oxopyrrolidines with Two Stereogenic Centers

Abstract

Aminolyses of racemic and prochiral 3-hydroxyesters with racemic amines are effectively catalyzed by Candida antarctica lipase. In these processes, the simultaneous resolution of the ester and the amine, or the corresponding asymmetrization-resolution, takes place. In all cases, the high enantioselectivity shown by the lipase toward all the reactants allows the preparation of enantiopure 3-hydroxyamides with very high diastereomeric ratios. These 3-hydroxyamides are used as starting materials in the synthesis of 3-hydroxy- and 2-oxopyrrolidines, both containing two stereogenic centers in their structures.

Biocatalysis in the Preparation of the Statin Side Chain

“…(13). From lipases, Candida antarctica lipase B (CAL-B) has been among the most potential alternatives [65][66][67][68]. CAL-B-catalysed hydrolysis of 27 Fig.…”

Enzymatic Aminolysis and Ammonolysis Processes in the Preparation of Chiral Nitrogenated Compounds

“…This selectivity can be used for the synthesis one-pot of optically active amide, ester and amine. Thus, CALB catalyses the amidation reaction between ethyl (+)-4-chloro-3-hydroxybutanoate and racemic amines (Scheme 19), leading to the corresponding amide with very high enantiomeric and diastereomeric excesses [55]. Besides, remaining ester and amine are recovered from the reaction media, also showing good ee.…”

“…The desymmetrization-resolution [55] reaction of dimethyl 3-hydroxyglutarate and phenylethylamine or 2-furylethylamine takes place in similar conditions to those given for 4-chloro-3-hydroxybutanoate. In this case a 2:1 molar ratio ester/amine is used to allow the 100% conversion of the ester.…”

Low Operational Stability of Enzymes in Dry Organic Solvents: Changes in the Active Site Might Affect Catalysis

“…Enzymes have been successfully employed to catalyze a number of transformations and chiral resolutions of biological and industrial importance in organic solvents [1,2,3,4,5,6,7,8,9,10]. In non-aqueous media autolysis (in the case of proteases) is prevented and the thermostability of the biocatalyst is increased [8,11,12].…”