In general, if the atoms that make up the ring contain heteroatoms, such rings become heterocycles, and organic compounds containing heterocycles are called heterocyclic compounds. An article called Visible-Light-Driven N-Heterocyclic Carbene Catalyzed γ- and ε-Alkylation with Alkyl Radicals, published in 2019, which mentions a compound: 60804-74-2, Name is Tris(2,2′-bipyridine)ruthenium bis(hexafluorophosphate), Molecular C30H24F12N6P2Ru, Application In Synthesis of Tris(2,2′-bipyridine)ruthenium bis(hexafluorophosphate).
The merging of photoredox catalysis and N-heterocyclic carbene (NHC) catalysis for γ- and ε-alkylation of enals with alkyl radicals was developed. The alkylation reaction of γ-oxidized enals with alkyl halides worked well for the synthesis γ-multisubstituted-α,β-unsaturated esters, including those with challenging vicinal all-carbon quaternary centers. The synthesis of ε-multisubstituted-α,β-γ,δ-diunsatd. esters by an unprecedented NHC-catalyzed ε-functionalization was also established.
Compounds in my other articles are similar to this one(Tris(2,2′-bipyridine)ruthenium bis(hexafluorophosphate))Application In Synthesis of Tris(2,2′-bipyridine)ruthenium bis(hexafluorophosphate), you can compare them to see their pros and cons in some ways,such as convenient, effective and so on.
Reference:
Highly efficient and robust molecular ruthenium catalysts for water oxidation,
Catalysts | Special Issue : Ruthenium Catalysts – MDPI