2007 Fiscal Year Final Research Report Summary
Research on Asymmetric Autocatalysis, Chiral Recognition and Origin of Chirality
| Project/Area Number |
15002010
|
|---|
| Research Category |
Grant-in-Aid for Specially Promoted Research
|
| Allocation Type | Single-year Grants |
|---|
| Review Section |
Science and Engineering
Chemistry
|
|---|
| Research Institution | Tokyo University of Science |
|---|
Principal Investigator |
SOAI Kenso Tokyo University of Science, Faculty of Science, Professor (90147504)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KAWASAKI Tsuneomi Tokyo University of Science, Faculty of Science, Assistant Professor (40385513)
SATO Itaru Tohoku University, Graduate School of Science, Associate Professor (80318196)
SHIBATA Takanori Waseda University, Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Professor (80265735)
|
|---|
| Project Period (FY) |
2003 – 2007
|
| Keywords | Asymmetric autocatalysis / Asymmetric automultiplication / Origin of Chirality / Chiral discrimination / Chiral inorganic crystal / Pyrimidyl alkanol / Asymmetric amplification / Absolute asymmetric synthesis |
|---|
| Research Abstract |
Pyrimidyl alkanol was found to act as an asymmetric autocatalysis in the reaction between pirimidine-5-carbaldehyde and diisopropylzinc, affording highly enantioenriched pyrimidyl alkanol with the same structure and absolute configuration. When asymmetric autocatalyst with very low enantiomeric excess (ee) was employed, significant amplification of ee was observed. Starting from asymmetric autocatalyst with very low ee, three consecutive asymmetric autocatalysis afforded practically enantiopure (>99.5% ee) pyrimidyl alkanol. Asymmetric autocatalysis has been employed to examine the validity of the origin of chirality. It was found that chiral inorganic crystal such as sodium chlorate act as chiral initiator of asymmetric autocatalysis. Direct irradiation of circularly polarized light (CPL) to racemic pyrimidyl alkanol and the subsequent asymmetric autocatalysis gave highly enantioenriched pyrimidyl alkanol with the related configuration to that of the direction of CPL. In addition, certain ketoolefin to which CPL induces the enantioenrichment by asymmetric photoequilibrium can act as a chiral initiator of asymmetric autocatalysis. Chiral crystals of achiral organic compound such as cytosine acts as chiral initiator of asymmetric autocatalysis. Spontaneous absolute asymmetric synthesis in the presence of achiral silica gel was achieved without adding chiral initiator in the reaction between pyrimidine-5-carbaldehyde and diisopropylzinc. Chiral discrimination of cryprochiral compound such as satirated quaternary hydrocarbon was achieved by using asymmetric autocatalysis. As described, we have found highly efficient asymmetric autocatalysis with amplification of enantioenrichment and applied the reaction to elucidate the origin of chirality and chiral discrimination.
|
