Resolution of Amines, Diamines, and Aminoalcohols

Normally ethyl acetate is used for the acylation of primary amines, in many cases, as acyl donor and solvent. Other acylating agents such as alkyl methoxy acetates are 

For this reaction, CALB catalyzes the amidation between a racemic P-hydroxyester and racemic amines, leading to the corresponding amide with very high enantiomeric and diastereomeric excesses. Besides, the remaining ester and amine are recovered from the reaction media, also showing good enantiomeric excesses. By this method, three enantioenriched interesting compounds are obtained from an easy one-step reaction. 

Another philosophy would be the one-pot resolution of two different nucleophiles, alcohol and amine [39]. An acylated racemic alcohol reacts with a racemic amine in 

The chemoenzymatic synthesis of the analgesic U-(—)-50,488 [41] and new C2-symmetric bisaminoamide ligands derived from N,N-disubstituted trans-cyclohexane, ,2-diamine [41] has been possible by a CALB-catalyzed resolution using ethyl acetate as solvent and acyl donor [42]. 

Aminoalcohols are an important class of compounds in medicinal chemistry because many drugs contain this structure. For their resolution, there are two possibilities acylation of amino function or an enzymatic transesterification with vinyl esters through the hydroxyl group. However, the amino or hydroxyl group must be protected, because if the starting material is the free aminoalcohol, the O- and N-acylation can take place, and in addition, there are migrations obtaining 

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