Autocatalysis for self-replication in synthesis

Self-replicating assemblies of molecules have been constructed, and some are even capable of asymmetric amplification. By comparison the Soai system is elegant in its simplicity, and has even been regarded as a triumph for reductionism. We have been studying chemical systems where an autocatalytic asymmetric amplification is coupled with a second autocatalytic but non-selective process to operate in parallel. Thus, in this way we are able to propagate chirality from asymmetrically amplifying catalyst to other chemical reactions with almost perfect enantioenrichment. Similarly, we discovered an unprecedented amplification of chirality in two interdependent autocatalytic processes operating in parallel. Our findings indicate a possible synergistic relationship, namely asymmetric amplification remains efficient and lead to a remote asymmetric amplification in the second chemical process. Furthermore, a bias towards one absolute sense of chirality - a left- or right-handed - may also arise from a judicious choice of sequences of chemical reactions one of which could be an autocatalytic reaction triggered by a target molecule with very low initial enantiopurity. The overall result allows the target molecule to generate is own catalyst for significant asymmetric amplification.

The chiral homogeneity of biomolecules, i.e., homochirality, is one of the striking features of life, and is considered to be closely related to self-organisation, thus to the origin and evolution of life. The proposed research aims to learn how to propag ate stereochemical information for a directed self-replication. In fact, many organic transformations provide chiral compounds bearing one or several functional groups that are reminiscent of the original catalysts. Thus, newly formed chiral products beco me suitable catalyst-candidates for asymmetric self-replication processes. In our research group, we have recently identified a set of autocatalytic reactions that show promise for self-replication of chirality. Knowledge of the key attributes of this asy mmetric catalysis is needed to form better models of self-replication of chirality. Beyond economical considerations, environmental concerns call for the development of green chemistry routes that minimize the environmental impact of synthetic methodologi es.