Small chiral organic molecules catalyse reactions with the same selectivity as enzymes, by forming a temporary, precisely shaped complex with the substrate. This flat top-down view of the same vessel makes the binding and release events easier to track than the orbiting 3D scene.
Cat + S <-> [Cat-S]#
[Cat-S]# -> Cat + P
v = Vmax*S / (Km + S)
- Substrate — prochiral substrate molecules diffusing toward the small-molecule catalyst sites.
- Catalyst loading — mol% of organocatalyst (e.g. a proline derivative) present in the reaction vessel.
- Binding affinity — how tightly the catalyst's hydrogen-bonding or enamine pocket holds the substrate (lowers apparent Km).
- Reaction temperature — thermal energy driving the transition state over its barrier faster at higher settings (raises kcat).
Organocatalysts avoid trace-metal contamination, which is critical when the product is a pharmaceutical intended for human dosing.