1985 Fiscal Year Final Research Report Summary
PREPARATION OF AMINO ACIDS LABELED AT SPECIFIED POSITION FOR LABORATORY USE
| Project/Area Number |
59850142
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
Synthetic chemistry
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| Research Institution | The University of Tokyo |
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Principal Investigator |
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| Project Period (FY) |
1984 – 1985
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| Keywords | Asymmetric Synthesis / Aminoacidato Complex / Amino Alkylmalonato Complex / 部分的重水素化による【^(13)C】シグナルの分裂 |
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| Research Abstract |
On decarboxylation, <(+)_(577)> -(Co(AMM)((4R,6R)-4,6-dimethy1-3,7-diaza-1,9-diaminononane)) <ClO_4> . <H_2O> (1) resulted in 34% R-alaninato and 66% S-alaninato, while <(-)_(546)> -(Co(AMM)((6R,8R)-6,8-dimethy1-2,5,9,12-tetraazatridecane))Br. <3H_2O> (2) resulted in 83% R-alaninato and 17% S-alaninato, where AMM represents an <alpha> -amino- <alpha> -methyl-malonato ion. Two X-ray crystal structure determinations of (1) and (2) have been performed. The results suggest that the important factor which governs the stereoselectivity on decarboxylation, is not the coordination geometry of AMM in the starting complex, but the asymmetric environment around the AMM chelate. The decarboxylation of the AMM complexes using DCl yielded <alpha> -deuterated alaninato complexes.
The reaction of <alpha> -aminomalonate (AM) with trans dichloro(3,7-diaza-1,9-nonanediamine)cobalt(III) perchlorate yielded unexpectedly N-(2-aminoethyl)-N-(4-aza6-aminohexyl)( <alpha> , <alpha> -diaminomalonate)cobalt(III) perchlorate. The X-ray crystal structure revealed that the complex has an unusually stable geminal diamine linkage containing an uncoordinated primary amino group, as a result of the new bond formation between the <alpha> -carbon of the <alpha> -aminomalonate unit and one of the secondary nitrogens of the tetraamine ligand.
The first obeservation of isotopic multiplets in the <^(13)CNMR> spectra of the cobalt(III) complexes with partially deutrated coordinated <NH_2> or NH groups have been achieved. It has been found that the magnitude of the three bond isotope effect is governed both by the type of the observed carbon atoms and by the dihedral angle C-C-N-H.
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