@article{TackeWagnerBrakmannetal.1993,
  author    = {Tacke, Reinhold and Wagner, S. A. and Brakmann, S. and Wuttke, F. and Eilert, U. and Fischer, L. and Syldatk, C.},
  title     = {Synthesis of acetyldimethyl(phenyl)silane and its enantioselective conversion into (R)-(1-hydroxyethyl)dimethyl(phenyl)silane by plant cell suspension culytures of Symphytum officinale L. and Ruta graveolens L.},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64299},
  year      = {1993},
  abstract  = {Starting from chlorodimethyl(phenyl)silane (3), acetyldimethyl(phenyl)silane (l) was prepared by a two-step synthesis in a total yield of 90\% [PhMe\(_2\)SiCl (3)-> PhMe\(_2\)SiCCOMe)=CH\(_2\) (4)-> PhMe\(_2\)SiC(O)Me (1)]. The prochiral acetylsilane 1 was transfonned enantioselectively into (R)-(1-hydroxyethyl)dimethyl(phenyl)silane [(R)-2] using plant cell Suspension cultures of Symphytum officinale L. or Ruta graveolens L. Under preparative conditions (300-mg scale, not optimized), (R)-2 was isolated in 15\% (Symphytum) and 9\% yield (Ruta), respectively. The enantiomeric purities of the products were 81\% ee (Syrnphytum) and 60\% ee (Ruta), respectively.},
  subject      = {Anorganische Chemie},
  language  = {en}
}
@article{TackeBrakmannWuttkeetal.1991,
  author    = {Tacke, Reinhold and Brakmann, S. and Wuttke, F. and Fooladi, J. and Syldatk, C. and Schomburg, D.},
  title     = {Stereoselective microbial reduction of racemic acetyl(t-butyl)methylphenylsilane by Trigonopsis variabilis (DSM 70714) and Corynebacterium dioxydans (ATCC 21766)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64109},
  year      = {1991},
  abstract  = {(SiR,CR)- and (SiS,CR)-t-butyl(l-hydroxyethyl)methylphenylsilane [(SiR,CR)-2 and (SiS,CR)-3] have been prepared by (R)-selective microbial rcduction of racemic acetyl(t-butyl)methylphenylsilane (rac-1) using resting free cells of the yeast Trigonopsis variabilis (DSM 70714) or the bacterium Corynebacterium dioxydans (ATCC 21766). The biotransfonnations were carried out on a 10 g scale. Afterseparation by column chromatography on silica gel, the optically active diastereomers (SiR,CR)-2 and (SiS,CR)-3 produccd by T. variabilis were obtained in good yields [74\% ((SiR,CR)-2). 78\% ((SiS,CR)-3)]. The products obtained from the reduction with C. dioxydans were isolated in significantly lower yields [20\% ((SiR,CR)-2), 20\% ((SiS,CR)-3)]; reaction conditions not optimized). Both bioconversions gave products with high enantiomeric purities (T. variabilis: 91\% ee ((SiR,CR)-2), 96\% ee ((SiS,CR)-3); C. dioxydons: ~ 991 ee ((SiR,CR)-l), ~ 99\% ee ((SiS,CR)-3)). To throw light on the stereochemical aspects of these biotransfonnations, an X-ray diffraction study was carried out on the 3,5-dinitrobenzoate of rac-(SiR,CS/SiS,CR)-3. In addition, 1H NMR spectroscopic stereochemical correlation studies were performed with the (S)-MTPA esters derived from (SiR,CR)-l, (SiS,CR)-3, rac-(SiR,CRjSiS,CS)-2 and rac-(SiR,CSjSiS,CR)-3 [rac-(SiR,CR/ SiS,CS)-2 and rac-(SiR,CS/SiS,CR)-3 were obtained by reduction of rac-1 with LiAIH\(_4\) in diethylether, followed by chromatographic separation of the diastereomers on silica gel]. These stereochemical studies allowed assignment of the absolute configurations and enantiomeric purities of the biotransformation products.},
  subject      = {Anorganische Chemie},
  language  = {en}
}
@article{SyldatkStoffregenWuttkeetal.1988,
  author    = {Syldatk, C. and Stoffregen, A. and Wuttke, F. and Tacke, Reinhold},
  title     = {Enantioselective reduction of acetyldimethylphenylsilane: a screening with thirty strains of microorganisms},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63906},
  year      = {1988},
  abstract  = {Thirty strains of microorganisms (bacteria, yeasts, fungi and green algae) were tested as resting free cells for their ability to transform acetyldimethylphenylsilane (1) enantioselectively into (R)-(1-hydroxyethyl) dimethylphenylsilane [(R)-2]. The biotransformations were monitared by GC (packed OV-17 column), and the enantiomeric purities of the products isolated were determined by HPLC (cellulose triacetate column, UV detection). All microorganisms tested were found to reduce 1 enantioselectively to give (R)-2. Under the test conditions used, the yeast Trigonapsis variabilis (DSM 70714) was found to 1 exhibif the highest specific activity (1.5 mg product x g cell wet mass\(^{-1}\) x min\(^{-1}\) ), whereas the highest enantioselectivities were observed for the bacteria Acinetobacter ca lcoaceticus (ATCC 31012) (>95\% ee), Brevfbacterium species (ATCC 21860) (90\% ee) and Corynebacterium dioxydans (ATCC 21766) (>95\% ee), the yeast Candida humico la (OSM 70067) (90\% ee), the fungus Cunninghame lla e legans (ATCC 26269) (94\% ee), as well as the cyanobacterium Synechococcus leopoliensis (94\% ee).· From the green algae tested, Chlamydomonas reinhardii showed the highest.enantioselectivity (85\% ee).},
  subject      = {Anorganische Chemie},
  language  = {en}
}
@article{SyldatkAndreeStoffregenetal.1987,
  author    = {Syldatk, C. and Andree, H. and Stoffregen, A. and Wagner, F. and Stumpf, B. and Ernst, L. and Zilch, H. and Tacke, Reinhold},
  title     = {Enantioselective reduction of acetyldimethylphenylsilane by Trigonopsis variabilis (DSM 70714)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63836},
  year      = {1987},
  abstract  = {Growing and resting cells of the yeast Trigonapsis variabilis (DSM 70714) can be used for the enantioselective reduction of the organosilicon compound acetyldimethylphenylsilane (J) to give optically active (R)-(1-hydroxyethyl)dimethylphenylsilane [(R)-2] in good yields. The enantiomeric purity of the isolated product was determined tobe 62-86\% ee depending on the substrate concentration used. Both substrate and product caused an inhibition of the reaction at concentrations higher than 0.35 and 0.5 g/1, respectively. Besides, higher substrate and product concentrations led to increased formation of the by-product 1,1,3,3-tetramethyl-1,3-diphenyldisiloxane. Considering the limiting substrate and product concentrations, it was possible to use the same biomass at least 5 times without significant loss of enzyme activity. 3-Methyl-3-phenyl-2-butanone (5) and acetyldimethylphenylgermane (7), which represent carbon and germanium analogues of 1, were also found to be accepted as substrates by Trigonapsis variabilis (DSM 70714). The reduction rates of the silicon {1) and germanium compound {7) were much higher than the transformation rate of the corresponding carbon analogue 5.},
  subject      = {Anorganische Chemie},
  language  = {en}
}
@article{HengelsbergTackeFritscheetal.1991,
  author    = {Hengelsberg, H. and Tacke, Reinhold and Fritsche, K. and Syldatk, C. and Wagner, F.},
  title     = {Synthesis and enantioselective enzymatic hydrolysis of rac-dimethylphenyl[1-(phenylacetamido)- ethyl]silane},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-64153},
  year      = {1991},
  abstract  = {Racemic dimethylphenyl(l-(phenylacetamido)ethyl)silane [rac-5) has been made by a four-step synthesis starting from (chloromethyl)dimethylphenylsilane [PhMe\(_2\)SiCH2Cl (1) ~ PhMe\(_2\)SiCH(Cl)Me (rac-2) - PhMe\(_2\)SiCH(l)Me (rac-3) - PhMe2SiCH(NH2)Me (rac-4) ~ PhMe\(_2\)SiCH[N(H)C(O)CH\(_2\)Ph]Me ( rac-5); total yield 41\% ). Enantioselective enzymatic hydrolysis of rac-5, catalyzed by immobilized penicillin G acylase (E.C. 3.5.1.11) from Escherichia coli 5K (pHM 12), gave (R)-(1- aminoethyl)dimethylphenylsilane [( R )-4] in 40\% yield with an enantiomeric purity of 92\% ee.},
  subject      = {Anorganische Chemie},
  language  = {en}
}
@article{FritscheSyldatkWagneretal.1989,
  author    = {Fritsche, K. and Syldatk, C. and Wagner, F. and Hengelsberg, H. and Tacke, Reinhold},
  title     = {Enzymatic resolution of rac-1,1-dimethyl-1-sila-cyclohexan-2-ol by ester hydrolysis or transesterification using a crude lipase preparation of Candida cylindracea},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-63967},
  year      = {1989},
  abstract  = {No abstract available},
  subject      = {Anorganische Chemie},
  language  = {en}
}