The first example of evolution of an iridanaphthalene into an indanone through an intermediate indenyl is reported, serving as a good example of starting material to obtain indanones. Two new iridanaphthalenes are obtained by intramolecular C−H activation of a phenyl ring of a carbene ligand in [IrCp*{C(OMe)CHCPh 2 }(L)]PF 6 (L = PPh 2 Me, PMe 3 ) complexes. It is demonstrated that these iridanaphthalene complexes can undergo a thermal reaction to give indenyl complexes and 3-phenylindanone.M etallacyclic aromatic compounds incorporating transition metals are a subject of great interest, since they display a behavior that includes properties from both aromatic organic and organometallic compounds. Although many metallabenzenes of osmium, iridium, platinum, and ruthenium are known, to the best of our knowledge only two metallanaphthalenes have been reported, one with osmium 1 and another with iridium. 2 The importance of this type of metal-organic functionality is emphasized by the fact that metal cyclopentadienyls can be formed from transitory metallabenzenes. 3 Analogously, an osmanaphthalene has been proposed as intermediate leading to an indenyl complex. 4 Recently, we have reported that the new (methoxy)-alkenylcarbeneiridium complex [IrCp*Cl{C(OMe)CH CPh 2 }(PPh 2 Me)]PF 6 (1a) reacts with amines to undergo the unexpected cleavage of the O−CH 3 bond instead of the usual aminolysis. 5 This peculiar behavior has prompted us to further explore the reactivity of these types of compounds. Here, we report that treatment of [IrCp*Cl{C(OMe)CHCPh 2 }-(L)]PF 6 (L = PPh 2 Me (1a), PMe 3 (1b)) with AgPF 6 gives high yields of the iridanaphthalene complexes [IrCp*{C(OMe)-CHC(o-C 6 H 4 )(Ph)}(L)]PF 6 (L = PPh 2 Me (2a), PMe 3 (2b)) through an intramolecular C−H activation of one of the phenyl rings of the carbene ligand (eq 1).The structures of both iridanaphthalene complexes have been confirmed by single-crystal X-ray diffraction (see the Supporting Information). Figure 1 shows the complex cation 2a. The iridium atom becomes part of a metallanaphthalene moiety and the metal coordination sphere is completed with a pentamethylcyclopentadienyl (Cp*) and a phosphane ligand.The NMR spectra support the solid-state structures of 2a,b (see the Supporting Information).Remarkably, the iridanaphthalene moiety is not stable and refluxing 2 in 1,2-dichloroethane or toluene for 24 h gives 3-phenylindanone (4) (eq 2). The same transformation occurs also at longer reaction times in dichloromethane at 35°C (eq 2).
The self-aggregation tendency of RAPTA complexes {[Ru(η 6 -p-cymene){PTA(-R)}Cl 2 ]X, R ) H (1BPh 4 and 1PF 6 ) and Me (2BPh 4 and 2OTf), and [Ru(η 6 -p-cymene)(PTA) 2 Cl]X (3BPh 4 and 3BF 4 )} in acetone-d 6 was inVestigated by means of diffusion NMR spectroscopy. On increasing the concentration, the protonated species (1X) undergoes intercationic selfaggregation driVen by hydrogen bonding that leads to the formation of 1 2 2+ dications and a small amount of 1 2 X + ion triples.
Iridanaphthalene complexes are synthesized from the corresponding methoxy(alkenyl)carbeneiridium compounds. The electronic character of the substituents on the 6-position of the metallanaphthalene ring is crucial from the point of view of the stability of the iridanaphthalene, [Ir[upper bond 1 start]Cp*{=C(OMe)CH=C(o-C[upper bond 1 end]6H4)(Ph)}(PMe3)]PF6, vs. its transformation to the corresponding indanone derivatives. Stability studies of the iridanaphthalene compounds revealed that strong electron donor substituents (-OMe) stabilize the iridanaphthalene, while weak electron donor (-Me) and electron withdrawing (-NO2) groups favor the formation of indanone derivatives. Two possible indanone isomers can be obtained in the conversion of the unstable iridanaphthalene complexes and a mechanism for the formation of these isomers is proposed.
Keywords: Rhenium / Hydrido ligands / P ligands / Fluxionality; L = PPh n (OR) 3−n , n = 0−2, R = Me, Et] show them to be highly fluxional classical hydride complexes. In the case of the ethoxy compounds 5b, 5d and 5f, three hydride interchange processes were observed in the temperature range 283−173 K and their activation parameters were determined by NMR line-shape analysis. A mechanism is proposed for each. Protonation of 1 and 5 with HBF 4 ·OMe 2
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