[4] Crabtree’s catalyst is effective for the hydrogenations of mono-, di-, tri-, and tetra-substituted substrates.

The catalyst is tolerant of weakly basic functional groups such as ester, but not alcohols (see below) or amines.

[6] The catalyst becomes irreversibly deactivated after about ten minutes at room temperature, signaled by appearance of yellow color.

More specifically, it catalyzes the direct exchange of a hydrogen atom with its isotopes deuterium and tritium, without the use of an intermediate.

With palladium on carbon in ethanol the product distribution is 20:80 favoring the cis isomer (2B in Scheme 1).

This is due to slight haptophilicity, an effect in which a functional group binds to the surface of a heterogeneous catalyst and directs the reaction.

Crabtree and graduate student George Morris discovered this catalyst in the 1970s while working on iridium analogues of Wilkinson's rhodium-based catalyst at the Institut de Chimie des Substances Naturelles at Gif-sur-Yvette, near Paris.