Kinetic resolution of fluorinated propargyl alcohols by lipase-catalyzed enantioselective transesterification

In order to obtain optically active fluorinated propargyl alcohols, a lipase-catalyzed kinetic resolution has been carried out. The effect of lipase types, organic solvents, reaction temperature, and acyl donors was examined in the lipase-catalyzed transesterification of 1,1,1-trifluoro-4-phenyl-3-butyn-2-ol. Various enantiomerically pure fluorinated propargyl alcohols have been successfully prepared in good enantiomeric excess (>84%) by Novozym 435-catalyzed transesterification with vinyl butanoate at 60 °C in n-hexane. In some cases, the enantiomeric purities were excellent (>99% ee).

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(R)-1,1,1,-Trifluoro-4-phenylbut-3-yn-olC10H7F3O[α]D25=-6.8 (c 0.02, CH3OH)Source of chirality: enzymatic resolutionAbsolute configuration: (R)

(R)-1,1,1-Trifluoro-4-phenylbut-3-yn-2-yl 4-nitrobenzoateC17H10F3NO4[α]D25=+45.9 (c 0.01, CH3OH)Source of chirality: enzymatic resolutionAbsolute configuration: (R)