Mikrobiologische Umwandlung von Silicium-Yerbindungen: Enantioselektive Reduktion von Acetessigsäure-(trimethylsilylalkyl)estern und deren Carba-Analoga/ Microbiological Transformation of Silicon Compounds: Enantioselective Reduction of Trimethylsilylalkyl Acetoacetates and their Carba-Analogues

Abstract

<jats:title>Abstract</jats:title><jats:p>The trimethylsilylalkyl acetoacetates 1 b and 2 b as well as their carba analogues 1 a and 2 a have been reduced microbiologically by Kloeckera corticis (ATCC 20109), leading to the corresponding ( + )-3(S)-hydroxybutanoates 3b, 4b, 3a, and 4a. The enantiomeric purity was found to be 80% (3a, 3b, 4b) and 65% (4a), respectively. The reduction of lb and 2b is - to our knowledge - the first example for a controlled microbiological transformation of organosilicon substrates.</jats:p>

Biocatalysis in Silicon Chemistry

“…[8][9][10][11][12][13][14] This work has been the subject of otherr eviewsa nd as such is only briefly discussed herein.…”

“…[9,13,15,16] These transformations were accomplished both with whole microorganisms and free enzymes. This work has been reviewed in greater detail previously, [17] and the reader is referred to this paper forf urther details about these biocatalytic reactions.…”

Synthesis and enantioselective enzymatic hydrolysis of rac-dimethylphenyl[1-phenylacetamido)ethyl]silane

“…Compound rac-5 was made by a four-step route starting from (chloromethyl)dimethylphenylsilane (1), as outlined in Scheme 1. Following a procedure described in The silane rac·5 was synthesized for the first time (total yield 41%, based on 1 used).…”

“…1 H NMR spectroscopic sturlies and GLC analyses of the biotransformation product, after derivatization with (S}-MTPA (see above), revealed the (R)-configuration for the excess enantiomer of 4 and an enantiomeric purity of 92% ee.…”

“…During our investigations on the synthesis of optically active organosilicon compounds by use of stereoselective biotransformations, both whole microbial cells [1][2][3][4][5][6] and free enzymes [7] were used as biocatalysts (for recent reviews see refs. [8][9][10].…”