Stable ruthenium indenylidene complexes with a sterically reduced NHC ligandElectronic supplementary information (ESI) available: Experimental procedures, NMR and X-ray data. See DOI: 10.1039/c2cc37514a

Stable and active Ru olefin metathesis catalyst 7 bearing a sterically reduced NHC ligand was synthesized. Upon action of pyridine, 7 forms complex 24 , the first example of an Ru-indenylidene catalyst bearing a labile pyridine ligand and a sterically less demanding NHC ligand. Smaller but smarter ruthenium-complex 7 bearing a sterically reduced NHC ligand oTol gives much better results in challenging olefin metathesis reactions as compared to "general purpose" SIMes containing catalysts, such as 1 .