Chemoenzymatic synthesis of enantiopure 1-phenyl-2-haloethanols and their esters

Abstract

Several secondary haloalcohols have been resolved by esterification catalyzed by lipases A and B from Candida antarctica (CALA and CALB, respectively). Immobilized CALB (Novozym 435) gave better selectivities and faster reaction rates than CALA (Novozyme 735) with all of the substrates. Vinyl butanoate was the favoured acyl donor compared to vinyl acetate due to remarkably faster reactions. The alcohols (R)-2a, (R)-2c and the butanoates (S)-3a-c have been isolated with 98–99% enantiomeric excess (ee) in good yields.

Keywords::

• Kinetic resolution
• CALA
• CALB
• enantiopure secondary alcohols
• enantiopure secondary esters

Acknowledgement

We thank Novozymes AS, Denmark, for gifts of Novozym 435 and 735, and ViaZym BV, The Netherlands, for gift of ViaKit CAL.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.