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Bulletin of the Korean Chemical Society (BKCS)

ISSN 0253-2964(Print)
ISSN 1229-5949(Online)
Volume 30, Number 12
BKCSDE 30(12)
December 20, 2009 

 
Title
Stereoselective Recognition of Amino Alcohols and Amino Acids by Carbonylurea- and Carbonyguanidinium-based Imine Receptors
Author
Raju Nandhakumar, Yun Soo Ahn, Hoe Jin Yoon, Kwan Mook Kim*
Keywords
Stereoselective recognition, Imine receptor, Chirality conversion, Amino alcohol, Amino acid
Abstract
New receptors 1-3 that bind stereoselectively amino alcohols and convert chirality of amino acidsvia imine bond formation were synthesized. The receptors have uryl (1), thiouryl (2) and guanidinium (3) groups all with additional phenylcarbonyl motifs, which are effective hydrogen bonding donors and play a key role in the stereoselective recognitions. The stereoselectivities were measured from the integration of 1H NMR peaks. Compound 1 and 2 showed the stereoselectivities for the imine formation with amino alcohols (KR/KS) in the range of 2 ~ 4, and compound 3 in the range of 4 ~ 8. Chirality conversion efficienciesof 1-3 for amino acids, i.e. D/L ratio at equilibrium, are in the range of 1.5 ~ 5.6, showing a little higher efficiency with 3. The additional phenylcarbonyl motifs in 1-3 were revealed not to contribute to significant enhancement of the selectivities.
Page
2938 - 2942
Full Text
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