Asymmetric Synthesis of the Nonproteinogenic Silicon-Containing α-Amino Acids (R)- and (S)-α-[(Trimethylsilyl)methyl]alanine§Dedicated to Professor Johann Weis on the occa
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- 作者：Steffen Falgner ; Christian Burschka ; Stephan Wagner ; Andreas Bhm ; Jrgen O. Daiss ; Reinhold Tacke
- 刊名：Organometallics
- 出版年：2009
- 出版时间：October 26, 2009
- 年：2009
- 卷：28
- 期：20
- 页码：6059-6066
- 全文大小：867K
- 年卷期：v.28,no.20(October 26, 2009)
- ISSN：1520-6041
文摘
The nonproteinogenic silicon-containing, α,α-disubstituted α-amino acids (R)- and (S)-2-amino-2-methyl-3-(trimethylsilyl)propanoic acid [(R)- and (S)-α-[(trimethylsilyl)methyl]alanine, (R)-1 and (S)-1] were synthesized by multistep syntheses, starting from diethyl malonate, and both were isolated with an enantiomeric purity of >99% ee. Compound rac-1 was also prepared. The key step of the asymmetric syntheses of (R)-1 and (S)-1 was an enantioselective enzyme-catalyzed (porcine liver esterase) ester cleavage of the prochiral substrate diethyl methyl[(trimethylsilyl)methyl]malonate. The absolute configurations of (R)-1 and (S)-1 were established by crystal structure analyses of (R)-1 and of its rhodium complex (SRh,RC)-16.