Asymmetric Induction Arising from Enantiomerically Enriched Carbon-13 Isotopomers and Highly Sensitive Chiral Discrimination by Asymmetric Autocatalysis

作者：Kawasaki Tsuneomi^*; Soai Kenso

来源：Bulletin of the Chemical Society of Japan, 2011, 84(9): 879-892.

DOI：10.1246/bcsj.20110120

Carbon-isotope chirality generated only by the substitution of carbon-13/carbon-12 can be amplified to enantioenriched 5-pyrimidyl alkanol by asymmetric autocatalysis, in which an extremely low enantiomeric excess (ca. 0.00005% ee) can automultiply during three consecutive reactions to >99.5% ee. Chiral carbon-isotopomers can act as a chiral trigger in the reaction between pyrimidine-5-carbaldehyde and diisopropylzinc to induce a small enantioselectivity in the resulting asymmetric autocatalyst, whose enantiomeric excess can be enhanced significantly by the subsequent asymmetric autocatalysis. Asymmetric autocatalysis has the enormous power to recognize the isotope chirality arising from the small difference between carbon (C-13/C-12) and hydrogen (D/H) isotopes. The tiny chiral influence in the hydrogen isotopically chiral amino acids such as glycine can be recognized and amplified by asymmetric autocatalysis. Furthermore, asymmetric autocatalysis can be applied to the highly sensitive chiral discrimination of cryptochiral compounds such as saturated quaternary hydrocarbon and isotactic polystyrene. Circularly polarized light, which is considered a possible candidate for the origin of chirality, acts as the chiral initiator in asymmetric autocatalysis, affording highly enantioenriched products with the absolute configuration correlated to the helicity of CPL. In addition, chiral crystals formed from achiral organic compounds can act as chiral initiators of asymmetric autocatalytic amplification of ee to afford enantioenriched (S)- and (R)-5-pyrimidyl alkanols corresponding to the solid-state chirality in chiral crystals.

• 出版日期2011-9-15