• Archives of Pharmacal Research
• /
• v.18 no.5
• /
• pp.369-370
• /
• 1995

• Bulletin of the Korean Chemical Society
• /
• v.25 no.10
• /
• pp.1471-1473
• /
• 2004

An efficient dynamic kinetic resolution of racemic ${\beta}$-hydroxyalkylferrocene and 1,1'-bis( ${\beta}$-hydroxyalkyl)-ferrocene derivatives was achieved using lipase/ruthenium-catalyzed transesterification in the presence of an acyl donor. The racemic ${\beta}$-hydroxyalkylferrocene derivatives were successfully transformed to the corresponding chiral acetates of high optical purities in high yields.

• Applied Chemistry for Engineering
• /
• v.17 no.6
• /
• pp.658-664
• /
• 2006

$\rho$, $\alpha$-dimethyl benzyl alcohol was resolved by the biphasic dynamic kinetic resolution (DKR). Acidic zeolite was used as a racemization catalyst while immobilized enzyme was employed for kinetic resolution. The effects of the process variables including nature of acyl donor, reaction temperature, substrate concentration, ratio of the two catalysts and stirring rate on the conversion and enantiomeric purity of the product were investigated. In DKR of $\rho$, $\alpha$-dimethyl benzyl alcohol, the product of 99% ee was obtained with a maximum yield of 88%. The high performance of the catalyst system was maintained in the condition of higher TON and under repeated use.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.11
• /
• pp.4067-4070
• /
• 2011

• Bulletin of the Korean Chemical Society
• /
• v.28 no.11
• /
• pp.2096-2098
• /
• 2007

• Journal of Microbiology and Biotechnology
• /
• v.17 no.1
• /
• pp.74-80
• /
• 2007

An enantioselective lipase gene (esf) for the kinetic resolution of optically active (S)-flurbiprofen was cloned from the new strain Serratia marcescens ES-2. The esf gene was composed of a 1,845-bp open reading frame encoding 614 amino acid residues with a calculated molecular mass of 64,978 Da. The lipase expressed in E. coli was purified by a three-step procedure, and it showed preferential substrate specificity toward the medium-chain-length fatty acids. The esf gene encoding the enantioselective lipase was reintroduced into the parent strain S. marcescens ES-2 for secretory overexpression. The transformant S. marcescens BESF secreted up to 217kU/ml of the enantioselective lipase, about 54-fold more than the parent strain, after supplementing 3.0% Triton X-207. The kinetic resolution of (S)-flurbiprofen was carried out even at an extremely high (R,S)-flurbiprofen ethyl ester [(R,S)-FEE] concentration of 500 mM, 130 kU of the S. marcescens ES-2 lipase per mmol of (R,S)-FEE, and 1,000 mM of succinyl ${\beta}-cyclodextrin$ as the dispenser at $37^{\circ}C$ for 12h, achieving the high enantiomeric excess and conversion yield of 98% and 48%, respectively.

• Bulletin of the Korean Chemical Society
• /
• v.26 no.6
• /
• pp.989-992
• /
• 2005

Dynamic kinetic resolution of $\alpha$-bromo carboxylic acid derivatives in nucleophilic substitution with chiral $\alpha$-amino ester nucleophiles in the presence of TBAI and DIEA has been investigated for stereoselective syntheses of 1,1'-iminodicarboxylic acid derivatives. Nucleophilic substitutions with various chiral $\alpha$-amino esters gave iminodiacetates 2-8 with stereoselectivities up to 87 : 13 dr. Also, the reactions of N-($\alpha$-bromo-$\alpha$-phenylacetyl)-L-alanine methyl ester with L-alanine, D-alanine and glycine methyl ester nucleophiles afforded N-carboxyalkyl dipeptide analogues 10-12 up to 90 : 10 dr.

• Bulletin of the Korean Chemical Society
• /
• v.27 no.3
• /
• pp.447-449
• /
• 2006

• Bulletin of the Korean Chemical Society
• /
• v.32 no.5
• /
• pp.1741-1744
• /
• 2011

• Bulletin of the Korean Chemical Society
• /
• v.35 no.1
• /
• pp.265-268
• /
• 2014