Activation of the CH bond. Pentahydridobis(tertiary- phosphine)iridium and related complexes as homogeneous catalysts for hydrogen transfer involving monoolefins

Clerici, Mario G.; Gioacchino, S. Di; Maspero, Federico; Perrotti, E.; Zanobi, A.

doi:10.1016/s0022-328x(00)91403-7

Cited by 54 publications

(8 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The major product is mer -IrHCl 2 (PPh 3 ) 3 6 with three mer -phosphine ligands and two trans chlorides, based on the 31 P{ 1 H} and proton NMR spectra. In fact, this type of reaction has been used before, − but the products depended on the kind of phosphine ligand. For example, iridium(III) complexes [IrCl 4 (P i Pr 3 ) 2 ][HP i Pr 3 ], 10 , IrHCl 2 (PCy 3 ) 2 , 11 , and IrCl 3 (PPh 2 Me) 3 , 12 , have been obtained in such reactions.…”

Section: Resultsmentioning

confidence: 99%

Iridium(III) Complex Containing a Unique Bifurcated Hydrogen Bond Interaction Involving Ir−H···H(N)···F−B atoms. Crystal and Molecular Structure of [IrH(η¹-SC₅H₄NH)(η²-SC₅H₄N)(PPh₃)₂](BF₄)·0.5C₆H₆

1996

View full text Add to dashboard Cite

A synthetic route to a new iridium(III) complex containing a novel proton hydride bonding interaction has been established. fac-IrH 3 (PPh 3 ) 3 reacts with 2-mercaptopyridine HSpy (Spy ) 2-SC 5 H 4 N) to give the known dihydride Ir(H) 2 (η 2 -Spy)(PPh 3 ) 2 8. Ir(H) 2 (η 2 -Spy)(PPh 3 ) 2 reacts with HSpy . HBF 4 to give [IrH(η 1 -SC 5 H 4 NH)(η 2 -SC 5 H 4 N)-(PPh 3 ) 2 ](BF 4 ) 9 which possesses a unique bifurcated hydrogen bonding interaction involving Ir-H‚‚‚H(N)‚‚‚F-B atoms with the distances of 2.0(1) Å for the H‚‚‚H unit and of 2.0(1) Å for the F‚‚‚H unit in the crystalline state. In solution the N-H‚‚‚H-Ir interaction is maintained according to 1 H T 1 (min) and nOe measurements. Isotope shifts in the chemical shifts of the hydride and one phosphorus of 9 have been observed in 1 H and 31 P{ 1 H} NMR spectra of [IrH(η 1 -SC 5 H 4 ND)(η 2 -SC 5 H 4 N)(PPh 3 ) 2 ](BF 4 ), 9-d 1 , prepared by the reaction of 9 with MeOD or CF 3 -CO 2 D. The crystal and molecular structure of [IrH(η 1 -SC 5 H 4 NH)(η 2 -SC 5 H 4 N)(PPh 3 ) 2 ](BF 4 )‚0.5C 6 H 6 9 has been solved by X-ray analysis: monoclinic space group P2 1 /c with a ) 17.723(3) Å, b ) 10.408(1) Å, c ) 26.073(4) Å, β ) 108.08(1)°, V ) 4572.0(11) Å 3 , and Z ) 4. The known complex fac-IrH 3 (PPh 3 ) 3 , 7, is made by a new and improved method by reacting mer-IrHCl 2 (PPh 3 ) 3 with NaOEt and H 2 (g). VT-1 H NMR spectra (+90 to -80 °C) of the hydrides of 7 reveal that the J AA and J AX couplings change in the AA′A′′XX′X′′ pattern (A ) 1 H, X ) 31 P) but that the complex is not fluxional. The T 1 (min) value of 0.144 s for the hydrides of 7 at -60 °C (300 MHz) indicates that the shortest H-H distances are about 1.8 Å.

show abstract

Section: Resultsmentioning

confidence: 99%

Iridium(III) Complex Containing a Unique Bifurcated Hydrogen Bond Interaction Involving Ir−H···H(N)···F−B atoms. Crystal and Molecular Structure of [IrH(η¹-SC₅H₄NH)(η²-SC₅H₄N)(PPh₃)₂](BF₄)·0.5C₆H₆

1996

View full text Add to dashboard Cite

show abstract

“…The 1 H NMR spectral data for both 1 and 2 are similar to those reported for analogous (Ph 3 P) 2 M(π-C 3 H 5 ) systems. 1,10,16 In addition to the resonances of the dfepe ligand, the anti allyl protons of 1 appear at δ 2.25 as a doublet of doublets due to coupling with the central allyl proton ( 3 J HH ) 14 Hz) and a single phosphorus atom ( 3 J PH ) 8 Hz). The syn protons appear as a broad doublet at δ 4.48 ( 3 J HH ) 8 Hz).…”

Section: Resultsmentioning

confidence: 99%

Polyhydride (Fluoroalkyl)phosphine Complexes of Iridium. Synthesis, Dynamics, and Reactivity Properties of (dfepe)₂Ir₂(μ-H)₃(H)

1996

View full text Add to dashboard Cite

The synthesis and reactivity properties of new dimeric iridium polyhydrides incorporating the acceptor ligand (C 2 F 5 ) 2 PCH 2 CH 2 (C 2 F 5 ) 2 (dfepe) are reported. Hydrogenolysis of (dfepe)-Ir(η 3 -C 3 H 5 ) (prepared by metathesis of [(dfepe)Ir(µ-Cl)] 2 with allylmagnesium chloride) afforded (dfepe) 2 Ir 2 (µ-H) 3 (H) (3) in high yield as an air-stable red crystalline solid. A triply bridged ground-state geometry for 3 was deduced from low-temperature NMR data and was confirmed by X-ray crystallography. Hydride site exchange mechanisms are proposed which are consistent with VT 1 H and 31 P NMR data. Although 3 is formally coordinatively saturated, hydride bridge dissociation readily occurs and leads to ligand addition reactions. Thus, treatment of tetrahydride 3 with 1 atm of H 2 at 20 °C quantitatively affords the hexahydride dimer [(dfepe)Ir(µ-H) 2 (H) 2 ] 2 (5). In the absence of H 2 , 5 rapidly loses H 2 in solution at 20 °C to re-form 3. The structure of 5 has been determined by X-ray crystallography. 3 also reacts with CO to give (dfepe)Ir(CO) 2 H (6), which loses CO under 1 atm of H 2 to reversibly afford (dfepe)Ir(CO)H 3 (7). The trihydride undergoes thermal H/D exchange with both D 2 (20 °C) and benzene-d 6 (120 °C), presumably via the intermediacy of (dfepe)Ir(CO)H. The tetrahydride 3 also undergoes H/D exchange with D 2 and benzene-d 6 under similar conditions. In the presence of tert-butylethylene, dehydrogenation of cyclopentane by 3 at 120 °C quantitatively affords CpIr(dfepe); a likely intermediate in this process is the dihydride dimer [(dfepe)Ir(µ-H)] 2 . (dfepe)Ir(η 3 -C 3 H 5 ) also reacts directly with cyclopentane at 120 °C to give CpIr(dfepe).

show abstract

“…Biological receptors of catecholamines in general are supposed to interact with catecholamines at the three binding sites; the ammonium cation, /3-hydroxy, and catechol groups. 8 The protonated macrocyclic hexaamine L-3H+ recognizing catecholamines only with the catechol part may be called a partial model of the catecholamine receptor. Whether the biological receptors actually carry the highly protonated active sites for the catechol binding remains to be seen.…”

Section: Resultsmentioning

confidence: 99%

“…fluorene34 at C-8. The O6 position of guanine as the main point of linkage of mitomycin C to nucleic acids has long been a subject of speculation, based on various indirect evidence.1, 8 It has now been shown that the Oe-substituted adduct is the major product with the dinucleoside phosphate d(GpC). Its method of isolation and characterization will facilitate the search for this and other mitomycin adducts in nucleic acids in vitro and in vivo.…”

mentioning

confidence: 99%

A catechol receptor model by macrocyclic polyamines

Kimura¹,

Watanabe²,

Kodama³

1983

J. Am. Chem. Soc.

View full text Add to dashboard Cite

Activation of the CH bond. Pentahydridobis(tertiary- phosphine)iridium and related complexes as homogeneous catalysts for hydrogen transfer involving monoolefins

Cited by 54 publications

References 14 publications

Iridium(III) Complex Containing a Unique Bifurcated Hydrogen Bond Interaction Involving Ir−H···H(N)···F−B atoms. Crystal and Molecular Structure of [IrH(η¹-SC₅H₄NH)(η²-SC₅H₄N)(PPh₃)₂](BF₄)·0.5C₆H₆

Iridium(III) Complex Containing a Unique Bifurcated Hydrogen Bond Interaction Involving Ir−H···H(N)···F−B atoms. Crystal and Molecular Structure of [IrH(η¹-SC₅H₄NH)(η²-SC₅H₄N)(PPh₃)₂](BF₄)·0.5C₆H₆

Polyhydride (Fluoroalkyl)phosphine Complexes of Iridium. Synthesis, Dynamics, and Reactivity Properties of (dfepe)₂Ir₂(μ-H)₃(H)

A catechol receptor model by macrocyclic polyamines

Contact Info

Product

Resources

About

Activation of the CH bond. Pentahydridobis(tertiary- phosphine)iridium and related complexes as homogeneous catalysts for hydrogen transfer involving monoolefins

Cited by 54 publications

References 14 publications

Iridium(III) Complex Containing a Unique Bifurcated Hydrogen Bond Interaction Involving Ir−H···H(N)···F−B atoms. Crystal and Molecular Structure of [IrH(η1-SC5H4NH)(η2-SC5H4N)(PPh3)2](BF4)·0.5C6H6

Iridium(III) Complex Containing a Unique Bifurcated Hydrogen Bond Interaction Involving Ir−H···H(N)···F−B atoms. Crystal and Molecular Structure of [IrH(η1-SC5H4NH)(η2-SC5H4N)(PPh3)2](BF4)·0.5C6H6

Polyhydride (Fluoroalkyl)phosphine Complexes of Iridium. Synthesis, Dynamics, and Reactivity Properties of (dfepe)2Ir2(μ-H)3(H)

A catechol receptor model by macrocyclic polyamines

Contact Info

Product

Resources

About

Iridium(III) Complex Containing a Unique Bifurcated Hydrogen Bond Interaction Involving Ir−H···H(N)···F−B atoms. Crystal and Molecular Structure of [IrH(η¹-SC₅H₄NH)(η²-SC₅H₄N)(PPh₃)₂](BF₄)·0.5C₆H₆

Iridium(III) Complex Containing a Unique Bifurcated Hydrogen Bond Interaction Involving Ir−H···H(N)···F−B atoms. Crystal and Molecular Structure of [IrH(η¹-SC₅H₄NH)(η²-SC₅H₄N)(PPh₃)₂](BF₄)·0.5C₆H₆

Polyhydride (Fluoroalkyl)phosphine Complexes of Iridium. Synthesis, Dynamics, and Reactivity Properties of (dfepe)₂Ir₂(μ-H)₃(H)