Regio- and enantio-selective acetylation of 3,3,3-trifluoro-2-arylpropane-1,2-diols using Candida antarctica lipase

Of nine commercially available lipases, lipase SP 435 from Candida antarcti ca, showed moderate enantioselectivity (E=17) for acetylation of racemic 3, 3,3-trifluoro-2-phenylpropane-1,2-diol, 2, with vinyl acetate in diisopropy l ether (S selectivity). The other eight had low selectivities, with E valu es below 10. The selectivity and reactivity of SP 435 for 2 was markedly im proved in dichloroethane (E=41). Moreover, SP 435 had moderate to high sele ctivity for the related compounds 3,3,3-trifluoro-2-(1-naphthyl)-propane-1, 2-diol, 4, (E=20), 3,3,3-trifluoro-2-(indol-3-yl)propane-1,2-diol, 6, (E=80 ), and 3,3,3-trifluoro-2-(pyrrol-2-yl)-propane-1,2-diol, 8, (E=17).