3:45 PM - 4:15 PM
[U11-07] Asymmetric autocatalysis (the Soai reaction) and the origin of homochirality
★Invited Papers
Keywords:homochirality, Soai reaction, asymmetric autocatalysis, origin of chirality, quartz, circularly polarized light
Biological homochirality such as L-amino acids and D-sugars has been a puzzle for the chemical origin of life. Although the origins of chirality of organic compounds have been proposed such as chiral quartz and circularly polarized light, the induced enantiomeric excess (ee) has been low.
Asymmetric autocatalysis is a reaction in which chiral compound acts as the chiral catalyst for its own production. The process is an automultiplication of a chiral compound. Pyrimidyl alkanol acts as an asymmetric autocatalyst in the addition of dialkylzincs to pyrimidine-5-carbaldehyde to produce more of itself with amplification of ee [1,2]. During the 3 consecutive asymmetric autocatalysis, the pyrimidyl alkanol automultiplies by the factor of 630,000 times. At the same time, significant amplification of ee of the alkanol from ca. 0.00005% ee to >99.5% ee was observed. Amplification of ee involves the aggregation of the asymmetric autocatalyst such as dimer, tetramer. Various origins of chirality such as quartz[3], circularly polarized light, chiral isotopomers[4], chiral crystals of achiral compounds such as gamma-glycine[5] trigger asymmetric autocatalysis to afford highly enantioenriched alkanol of the correlated chirality to that of the origins of chirality[6].
Asymmetric autocatalysis is a reaction in which chiral compound acts as the chiral catalyst for its own production. The process is an automultiplication of a chiral compound. Pyrimidyl alkanol acts as an asymmetric autocatalyst in the addition of dialkylzincs to pyrimidine-5-carbaldehyde to produce more of itself with amplification of ee [1,2]. During the 3 consecutive asymmetric autocatalysis, the pyrimidyl alkanol automultiplies by the factor of 630,000 times. At the same time, significant amplification of ee of the alkanol from ca. 0.00005% ee to >99.5% ee was observed. Amplification of ee involves the aggregation of the asymmetric autocatalyst such as dimer, tetramer. Various origins of chirality such as quartz[3], circularly polarized light, chiral isotopomers[4], chiral crystals of achiral compounds such as gamma-glycine[5] trigger asymmetric autocatalysis to afford highly enantioenriched alkanol of the correlated chirality to that of the origins of chirality[6].