Chapter 11 - Asymmetric Autocatalysis and Biomolecular Chirality

Abstract

The chapter describes asymmetric autocatalysis as an asymmetric synthesis where structures of a chiral catalyst and of a chiral product are identical. Asymmetric autocatalyses of chiral pyridyl, pyrimidyl, and quinolyl alkanols in the enantioselective addition to the corresponding aldehydes afford chiral pyridyl, pyrimidyl, and quinolyl alkanols of the same structures and configurations with those of asymmetric autocatalysts, respectively. Amplification of enantiomeric excess is observed in one-pot or consecutive asymmetric autocatalyses of pyrimidyl and quinolyl alkanols. From trace amounts of pyrimidyl and quinolyl alkanols with low enantiomeric excesses, increased amount of chiral pyrimidyl and quinolyl alkanols with very high excesses are formed without any assistance of other chiral molecules. Thus, asymmetric autocatalysis with amplification of excesses is one of the most straightforward pathways leading to the homochirality of a molecule. It should be noted that chiral (R)-pyrimidyl alkanol can be transformed into L-valine according to a recent observation.