doi:10.1021/acs.organomet.1c00068engBuil M.L.Collado A.Esteruelas M.A.Gomez-Gallego M.Izquierdo S.Iglesias Nicasio A.Oñate E.Sierra M.A.Preparation and degradation of rhodium and iridium diolefin catalysts for the acceptorless and base-free dehydrogenation of secondary alcoholsART-2021-126640Rhodium and iridium diolefin catalysts for the acceptorless and base-free dehydrogenation of secondary alcohols have been prepared, and their degradation has been investigated, during the study of the reactivity of the dimers [M(µ-Cl)(I4-C8H12)]2 (M = Rh (1), Ir (2)) and [M(µ-OH)(I4-C8H12)]2 (M = Rh (3), Ir (4)) with 1, 3-bis(6'-methyl-2'-pyridylimino)isoindoline (HBMePHI). Complex 1 reacts with HBMePHI, in dichloromethane, to afford equilibrium mixtures of 1, the mononuclear derivative RhCl(I4-C8H12){¿1-Npy-(HBMePHI)} (5), and the binuclear species [RhCl(I4-C8H12)]2{µ-Npy, Npy-(HBMePHI)} (6). Under the same conditions, complex 2 affords the iridium counterparts IrCl(I4-C8H12){¿1-Npy-(HBMePHI)} (7) and [IrCl(I4-C8H12)]2{µ-Npy, Npy-(HBMePHI)} (8). In contrast to chloride, one of the hydroxide groups of 3 and 4 promotes the deprotonation of HBMePHI to give [M(I4-C8H12)]2(µ-OH){µ-Npy, Niso-(BMePHI)} (M = Rh (9), Ir (10)), which are efficient precatalysts for the acceptorless and base-free dehydrogenation of secondary alcohols. In the presence of KOtBu, the [BMePHI]- ligand undergoes three different degradations: Alcoholysis of an exocyclic isoindoline-N double bond, alcoholysis of a pyridyl-N bond, and opening of the five-membered ring of the isoindoline core. ©2021http://zaguan.unizar.es/record/11965910.1021/acs.organomet.1c00068http://zaguan.unizar.es/record/119659oai:zaguan.unizar.es:119659info:eu-repo/grantAgreement/ES/DGA/E06-17Rinfo:eu-repo/grantAgreement/ES/MICINN/PID2019-108429RB-I00info:eu-repo/grantAgreement/ES/MINECO-AEI-FEDER/RED2018-102387-Tinfo:eu-repo/grantAgreement/ES/MINECO/CTQ2017-82935-POrganometallics 40, 7 (2021), 989-1003byhttps://creativecommons.org/licenses/by/4.0/deed.esinfo:eu-repo/semantics/openAccess