Catalytic cycle

A catalytic cycle in Heck reaction show catalytic cycles.

Sacrificial catalysts

Often a so-called sacrificial catalyst is also part of the reaction system with the intent purpose of regenerating the true catalyst in each cycle. As the name implies, the sacrificial catalyst is not regenerated and irreversibly consumed. This sacrificial compound is also known as a stoichiometric catalyst when added in stoichiometric quantities compared to the main reactant. Usually the true catalyst is an expensive and complex molecule and added in quantities as small as possible. The stoichiometric catalyst on the other hand should be cheap and abundant.^{[citation needed]}