The concept of solid catalyst coated with a 1 nm layer of an ionic liquid [BMIM+ BF4-] was employed, resulting in a 22-fold increase in β(Z)-selectivity for Rh(I)- and Rh(III)- complexes based on N- and O-chelating N-heterocyclic carbenes (NHCs).

The primary data files for the synthesized ligand and complexes as well as performed catalysis are provided. The labeling of the data files proceeded according to the corresponding figures in the supporting information. It includes NMR of the synthesized complexes and catalysis, physisorption measurements and IR measurements. The Crystal data for the complexes Rh3, Rh5 and Rh6 is deposited in the Cambridge Structural Database (CSD) of the Cambridge Crystallographic Data Centre (CCDC).