In order to explain the origin of the single-handedness of the molecules of life (biological homochirality), the appearence of an initial enantiomeric imbalance by spontaneous mirror-symmetry breaking (SMSB) in prebiotic reactions is usually assumed, but examples of its experimental realization are very scarce. SMSB in the self-assembly of achiral molecules is much more common, and the chirality sign of the resulting supramolecular system can be controlled by the action of macroscopic chiral forces. We have proposed a new mechanism for the generation of net chirality in molecular systems, in which the SMSB takes place in the formation of chiral supramolecular dissipative structures from achiral monomers, leading to asymmetric imbalances in their composition that are subsequently transferred to a standard enantioselective catalytic reaction, dodging in this way the highly limiting requirement of finding suitable reactions in solution that show enantioselective autocatalysis. We propose the name “absolute asymmetric catalysis” for this approach, in which an achiral monomer is converted to a nonracemic chiral aggregate that is generated with SMSB and that is catalytically active.
We present in this Account a step-by-step narrative of the development of this prebiotically plausible, alternative mechanism for the emergence of net chirality in molecular reactions.
{N
1-[2-(Butylselanyl)benzyl]-N
2,N
2-dimethylethane-1,2-diamine}dichloridomercury(II)