WilkinsonKatalyse

WilkinsonKatalyse is a term used in catalytic chemistry to describe Wilkinson's catalyst and related rhodium‑phosphine systems, with a focus on homogeneous hydrogenation of alkenes. Named after Sir Geoffrey Wilkinson, the catalyst RhCl(PPh3)3 was developed in the 1960s and became a foundational example of homogeneous catalysis. Wilkinson's catalyst enabled selective hydrogenation under relatively mild conditions and helped establish the practical viability of transition‑metal catalysts for industry and academia. In typical cycles, the active species forms a dihydride upon reaction with H2; an alkene coordinates to the rhodium center, inserts into a Rh–H bond, and reductive elimination releases the hydrocarbon product while regenerating the catalyst.

The scope of WilkinsonKatalyse includes a wide range of terminal alkenes and some internal substrates, with higher activity for less hindered cases. The system is usually used under an inert atmosphere with suitable phosphine ligands in solvents such as toluene or THF. The ligand environment influences reactivity and selectivity; while the parent catalyst is achiral and typically yields non‑stereoselective hydrogenation, chiral ligands can be explored to affect enantioselectivity.

Limitations include slower rates for hindered substrates, sensitivity to impurities that poison the catalyst, and the need for hydrogen gas under pressure in some applications. Ongoing work in WilkinsonKatalyse addresses catalyst modification, immobilization on supports, and integration with heterogeneous approaches to improve turnover and recyclability.

See also: Homogeneous catalysis, hydrogenation, rhodium complexes. References include classic reports by Wilkinson and co‑workers and reviews on Rh/phosphine hydrogenation.