The present work describes the facile and efficient synthesis of various [RuCl2(NHC)(NHCewg)(CHPh)]-complexes. NHCewg-ligands are N-heterocyclic carbenes substituted with electron withdrawing groups. Due to donor properties comparable to those of trialkylphosphines, those ligands act as efficient leaving groups in ruthenium precatalysts of the grubbs type. The new synthetic route to such complexes requires fewer synthetic steps than before, avoids the use of PCy3 and affords excellent yields of the respective [RuCl2(NHC)(NHCewg)(CHPh)] complexes. The present work describes furthermore the utilisation of prior described complexes in the ethenolysis of olefins with trisubstituted double bonds. It could be demonstrated that squalene, natural rubber and even end-of-life tire granulate can undergo ethenolysis reactions, leading to the isolation of a range of oligomeric isoprenes. The evolved concept enables the efficient recovery of organic solubles, which are primarily composed of oligomeric 1,4-cis isoprenes, from end-of-life tire granulate.