2006 Fiscal Year Final Research Report Summary
Synthesis of chiral calixarenes and application as functional organic catalysts
| Project/Area Number |
17560685
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Catalyst/Resource chemical process
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| Research Institution | Sojo University |
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Principal Investigator |
GOTO Koichi Sojo University, Applied Life Science, Associate Professor, 生物生命学部, 助教授 (30279377)
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| Project Period (FY) |
2005 – 2006
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| Keywords | Chiral Calixarene / Amino Acid Ester / Enantioselective Hydrolysis / Molecular Recognition / Supramolecular Chemistry |
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| Research Abstract |
The racemic mixture of chiral calix [4]arenes (5-tert-butyl-11-methyl-17,23-diphenyl-25,26,27,28-tetrahydroxycalix [4]arene) with three different upper rim substituents was synthesized by the fragmentation-condensation of p-substituted phenol dimmers (2-(5-methylsalicyl)-4-tert-butylphenol and 3-(3-hydroxymethyl-5-phenylsalicyl)-5-phenyl-2-hydroxybenzyl alchol) according to K. No and coworkers' multi-step method. On the other hand, amino acid esters (Z-D(L)-Ala-PNP, Z-D(L)-Trp-PNP) were prepared from N-(benzyloxycarbonyl)-D(L)-amino acids by esterification of the COOH group with p-nitrophenol and dicyclohexylcarbodiimide. The calix[4]arenes and amino acid esters were confirmed by elemental analysis, specific rotation, IR and NMR spectroscopic measurements. With respect to the hydrolysis of Z-D(L)-Trp-PNP mediated by the calix[4]arenes in the presence of Z-L-Phe-OH, a little inhibition effect was observed on the basis of the rate constants. Particularly, the hydrolysis of D-substrate tended to be slightly slower than that of L-substrate. Furthermore, the computer modeling (molecular mechanics) studies indicated that the calix[4]arene would adopt a "cone" conformation. These results suggest that the calix[4]arenes could form inclusion complexes with Z-D(L)-Trp-PNP. Probably, the stereochemical arrangements of the chiral calix[4]arenes may induce the enantioselectivity for the hydrolysis of Z-D(L)-Trp-PNP.
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