Candida antarctica lipases acting as versatile catalysts for the synthesis of enantiopure (R)- and (S)-1-(2-phenylthiazol-4-yl)ethanamines

• A new synthesis of both enantiomers of 1-(2-phenylthiazol-4-yl)ethanamines, by enzymatic kinetic resolution, was developed.
• The CaL-B-mediated kinetic resolution of amines occurred optimal using ethyl n-butyrate as acyl donor in acetonitrile.
• The CaL-B-mediated hydrolysis of racemic amides was optimal in water at 45 °C, with no need for additional co-solvents.
• To avoid the chemical decomposition and/or racemization during the deprotection of (R)-amides, CaL-A on Celite was used.

The synthesis of both enantiomers of four new phenylthiazole-based amines by enantiomer-selective acylation of racemic amines and by hydrolysis of the corresponding racemic amides using lipase B from Candida antarctica (Novozyme 435) as chiral catalyst was performed with good yields and excellent enantioselectivities. In order to prevent the frequently occurring partial racemization of enantiopure amides during chemical hydrolysis to the corresponding (R)-amines, the deprotection of the N-acylated (R)-enantiomers by mild enzymatic hydrolysis with lipase A from C. antarctica immobilized on Celite was also developed.

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