Lipase-catalysed enantioselective synthesis of naphthyl trifluoromethyl carbinols and their corresponding non-fluorinated counterparts

Abstract

Enantioselective synthesis of both enantiomers of β- and α-naphthyl trifluoromethyl carbinols (R)- 1 a , (S)- 1 a , (R)- 2 a , (S)- 2 a has been achieved through acylation of the corresponding racemic alcohols (RS)- 1 a and (RS)- 2 a with vinyl acetate in the presence of lipase PS. The effect of fluorine atoms on the extent and enantioselectivity of the process has been tested by carrying out the same biocatalytic transformation on their non-fluorinated counterparts (RS)- 1 b and (RS)- 2 b . The order of reactivity follows the trend (RS)- 1 b > (RS)- 2 b ≈ (RS)- 1 a > (RS)- 2 a . Effect of the hydrophobicity of the solvent in the resolution of (RS)- 1 a is also presented.