Preparative asymmetric deoxygenation of alkyl aryl sulfoxides by Rhodobacter sphaeroides f sp denitrificans

Preparative enantioselective deoxygenation of racemic alkyl aryl sulfoxides by intact cells of Rhodobacter sphaeroides f.sp. denitrificans was examined. In methyl p-substituted phenyl sulfoxides, (S)-enantiomers were exclusively deoxygenated while enantiomerically pure (R)-isomers were recovered in good yield. For poor substrates such as ethyl phenyl sulfoxide, the repetition of the incubation after removing the toxic product was effective in enhancing the e.e. of recovered (R)-enantiomers. (C) 1997 Elsevier Science Ltd. All rights reserved.