Malan, F.P. (Frederick)Singleton, EricVan Rooyen, Petrus H.Albrecht, MartinLandman, Marile2019-07-152019-06Malan, F.P., Singleton, E., Van Rooyen, P.H. et al. Synthesis, stability, and (de)hydrogenation catalysis by normal and abnormal alkene- and picolyl-tethered NHC ruthenium complexes. Organometallics (2019) 38(13):2624-2635.0276-7333 (print)1520-6041 (online)10.1021/acs.organomet.9b00178http://hdl.handle.net/2263/70719A series of p-cymene and cyclopentadienyl Ru(II)-aNHC complexes were synthesized from 2-methylimidazolium salts with either an N-bound alkenyl (1, 3) or picolyl tether (6, 7). The C(5)-Me substituted alkenyl-tethered analogues (2, 4) were also synthesized. Ag-mediated C(2)-dealkylation was a prominent side reaction that led to the formation of normally bound NHC Ru(II) complexes, which in selected cases were isolated (5, 8). A C(4)- over C(2)-selectivity for ruthenium binding was established by protecting the C(2)-position with an iPr group on the imidazolium precursor, for which unique p-cymene (9) and cyclopentadienyl (10) Ru(II)-aNHC derivatives were synthesized. All complexes were applied in the transfer hydrogenation of ketones and in secondary alcohol oxidation, with higher catalytic activity for the p-cymene over the cyclopentadienyl systems, as well as the alkenyl- over the picolyl-containing aNHC complexes.enThis document is the Accepted Manuscript version of a Published Work that appeared in final form in Organometallics, © 2019 American Chemical Society after peer review and technical editing by the publisher.N-Heterocyclic carbenes (NHCs)Ruthenium complexesSynthesisStability(De)hyrogenationPostprint Article