Synthesis of parent amido (NH2)-bridged dinuclear complexes of ruthenium and iridium by stepwise transfer hydrogenation of μ-azido complexes

Abstract

The azido-bridged diruthenium and diiridium complexes [(LMCl)(2)(micro-N(3))(2)] (LM = CymRu, Cp*Ir; Cym = eta(6)-p-cymene, Cp* = eta(5)-C(5)(CH(3))(5)) are sequentially converted into the amido-bridged complexes [(LMCl)(2)(micro-NH(2))(micro-N(3))] and [(LMCl)(2)(micro-NH(2))(micro-H)] upon treatment with 2-propanol and a base.

Synthesis and anticancer activity of carbosilane metallodendrimers based on arene ruthenium(ii) complexes

“…All the distances and angles of this structure are in the expected range having values comparable to those in the related Ru(η 6 - p -cymene)Cl 2 NH 2 R species. 60 …”

Terminal and Bridging Parent Amido 1,5‐Cyclooctadiene Complexes of Rhodium and Iridium

“…However, when dichloroethane was used as substrate, the clean formation of the symmetrical di-chloro complex [{Ir- (7) was observed, along with released ethylene (Scheme 2). The diiridium adducts 5-7 were fully characterized by multinuclear NMR spectroscopy, including 15 N-1 H HMBC, 13 C-1 H HSQC, and COSY bidimensional techniques, mass spectrometry, IR spectroscopy, and elemental analyses.…”

“…So far, rational synthetic routes to these compounds involve mainly salt metathesis reactions that displace halogen ligands with amido nucleophiles,10 dehydrohalogenation of NH 3 metallic adducts,11 or deprotonation of cationic NH 3 adducts with strong bases 12. Recently, parent‐amido‐bridged complexes of ruthenium and iridium have been obtained by transfer hydrogenation to dinuclear azido‐bridged complexes with 2‐propanol,13 and a terminal amido iridium complex has been isolated from the hydrogenation of a unique IrN nitrido compound 14. It is important to mention that none of these synthetic methods makes use of ammonia as the source of “NH 2 ” fragments, which we believe is a crucial factor to achieve further functionalization of ammonia 15…”

“…So far, the reactivity of terminal parent amido complexes has been focused in proton exchange processes with weak acids,11a, 12b, 21 insertions of carbon monoxide into the NH bond,10b and reductive elimination of ammonia,11b a work that evidences a high basicity at the terminal amido nitrogen, which bears an exposed and reactive free electron pair. The situation is quite different in bridging parent amido complexes, in which the lone electronic pair is usually tightly bounded in a dative fashion to a second metal 13. 16a, b, f, 18, 24 In this context, a significant contribution has been recently reported dealing with the role of [Ir‐NH 2 ‐Ir] linkages in catalytic transfer hydrogenation, enlightening a novel binuclear, outer‐sphere Noyori‐like mechanism, in which the NH 2 groups behave as non‐innocent ligands playing a key role in alcohol dehydrogenation and imido formation 25…”

“…[12] Recently, parent-amido-bridged complexes of ruthenium and iridium Abstract: The ready availability of rare parent amido d 8 On the other hand, we tested complexes 1 and 2 as catalysts in the transfer hydrogenation of acetophenone with iPrOH without the use of any base or in the presence of Cs 2 CO 3 , finding that the iridium complex 2 is more active than the rhodium analogue 1. Keywords: cyclooctadienyl ligands · hydrogen transfer · iridium · parent amido · rhodium have been obtained by transfer hydrogenation to dinuclear azido-bridged complexes with 2-propanol, [13] and a terminal amido iridium complex has been isolated from the hydrogenation of a unique IrN nitrido compound. [14] It is important to mention that none of these synthetic methods makes use of ammonia as the source of "NH 2 " fragments, which we believe is a crucial factor to achieve further functionalization of ammonia.…”