| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1347987 | Tetrahedron: Asymmetry | 2007 | 7 Pages |
The influence of microwave irradiation on the Novozyme 435® (Candida antarctica lipase) catalyzed kinetic resolution of secondary alcohols with different functional groups was studied in comparison to the use of conventional heating at 60 °C. p-Chlorophenyl acetate was used as an acyl donor and toluene as the solvent. (±)-1-Phenyl-1-propanol 1, (±)-1-(4-bromophenyl)-propan-1-ol 3, (±)-1-phenylbut-3-en-1-ol 5 and (±)-3-bromo-2-(2-hydroxypropyl)-1,4-dimethoxynaphthalene 7 were successfully resolved into their (S)-alcohols and (R)-esters, respectively, in good enantiomeric excess. Resolution of (±)-ethyl-5-(4-methoxybenyloxy)-3-hydroxypentanoate 9 afforded its (R)-alcohol and (S)-ester using this method. In addition, microwave-assisted lipase transesterification of meso-symmetric diol 11 effected desymmetrization to ester 12 with high enantiomeric excess. In all cases studied, the conversion value for the microwave-assisted lipase kinetic resolution of secondary alcohols was higher than that obtained using conventional heating.
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(R)-1-Phenyl-1-propyl acetateC11H14O2Ee = 99%[α]D20=+98.2 (c 1.30, CHCl3)Source of chirality: enzyme-mediated kinetic resolutionConfiguration predicted: (R)
(R)-1-(4-Bromophenyl)-1-propyl acetateC11H13BrO2Ee = 99%[α]D20=+85.0 (c 0.50, CHCl3)Source of chirality: enzyme-mediated kinetic resolutionConfiguration predicted: (R)
(R)-3-Bromo-2-(2-acetoxypropyl)-1,4-dimethoxynaphthaleneC17H19BrO4Ee = 99%[α]D20=+17.8 (c 0.17, CHCl3)Source of chirality: enzyme-mediated kinetic resolutionConfiguration predicted: (R)
(S)-Ethyl-5-(4-methoxybenzyloxy)-3-acetoxypentanoateC17H24O6Ee = 99%[α]D20=+6.0 (c 5.08, CHCl3)Source of chirality: enzyme-mediated kinetic resolutionConfiguration predicted: (S)
(R)-Ethyl-5-(4-methoxybenyloxy)-3-hydroxypentanoateC15H22O5Ee = 43%[α]D20=+4.5 (c 3.44, CHCl3)Source of chirality: enzyme-mediated kinetic resolutionConfiguration predicted: (R)
