Chiral catalyst

A chiral catalyst provides a handed reaction environment that can favour formation of one enantiomer. The competing substrate–catalyst arrangements are diastereomeric, so their activation free energies can differ.^[ref]

For two competing pathways obeying transition-state kinetics, $k_1/k_2\simeq \exp [-(\Delta G_1^{‡}-\Delta G_2^{‡})/(RT)]$. A modest free-energy difference can therefore produce a substantial product ratio. Reversible steps and product equilibration require additional analysis.