12092-47-6Relevant academic research and scientific papers
Application of microwave dielectric loss heating effects for the rapid and convenient synthesis of organometallic compounds
Baghurst, David R.,Mingos, D. Michael P.,Watson, Michael J.
, p. C43 - C45 (1989)
Diolefin-rhodium(I) and -iridium(I) complexes have been synthesised in a sealed Teflon container by use of microwave heating.The products are obtained in excellent yields and in less than 1 minute compared with many hours by conventional reflux techniques
Design and application of a reflux modification for the synthesis of organometallic compounds using microwave dielectric loss heating effects
Baghurst, David R.,Mingos, D. Michael P.
, p. C57 - C60 (1990)
A commercially available microwave oven has been modified so that synthese involving the refluxing of organic solvents can be safely and conveniently undertaken.The application of this technique for accelerating the rates of reactions leading to the synth
Immobilized chiral rhodium nanoparticles stabilized by chiral P-ligands as efficient catalysts for the enantioselective hydrogenation of 1-phenyl-1,2-propanedione
Ruiz, Doris,M?ki-Arvela, P?ivi,Aho, Atte,Chiment?o, Ricardo,Claver, Carmen,Godard, Cyril,Fierro, José L.G.,Murzin, Dmitry Yu.
, (2019)
This work reports the efficient synthesis of enantio-enriched alcohols by asymmetric hydrogenation of 1-phenyl-1,2-propanedione using chiral nanoparticles (NPs) supported on SiO2. The chiral catalysts were synthesized by reducing the [Rh(μ?OCH3)(C8H12)]2 precursor under H2 in the presence of P-chiral ligands as stabilizers and SiO2 as support. Synthesis of catalysts in mild conditions was performed from labile organometallic precursor and chiral ligands provided small and well defined chiral nanoparticles (≤ 3 nm). The catalysts were characterized by XPS, HR-TEM, EDS, XRD and N2 physisorption isotherm. The physical chemical properties of the materials were correlated with the catalytic results obtained in the asymmetric hydrogenation of 1-phenyl-1,2-propanedione. In 1-phenyl-1,2-propanedione hydrogenation the best results using chiral catalysts allowed 98% conversion and enantiomeric excess of 67% to (R)-1-hydroxy-1-phenyl-propan-2-one and 59% for (R)-2-hydroxy-1-phenylpropan-1-one. Catalyst recycling studies revealed that chiral nanoparticles immobilized on SiO2 are stable. These catalysts do not need extra amount of chiral modifier or inducer added in situ and could be reused without loss of enantioselectivity.
Synthesis of M2Rh2 Bis(μ3-carbon dioxide) complexes from the reaction between [Rh(OH) (η4-COD)]2 and cationic metal carbonyls
Tetrick, Stephen M.,Xu, Chongfu,Pinkes, John R.,Cutler, Alan R.
, p. 1861 - 1867 (1998)
The M2Rh2 bis(μ3-CO2) complexes [Cp*(CO)(NO)Re(CO2)Rh(η4-cod)]2 (1) and [Cp*(CO)2-MCO2Rh(η4-cod)] 2, M = Fe (2) and Ru (3), were synthesized in moderate to high yields from treating [Rh(OH)(η4-cod)]2 (cod = 1,5-cyclooctadiene) with the carbonyl salts Cp*(L)(CO)2M+ (L = CO, M = Fe, Ru; L = NO, M = Re) and a base. [An alternative synthesis of 1 and its crystallographic structure determination has been reported.] Although details on using several bases in the synthesis of 2 are reported, the use of volatile EtMe2N in excess as the base is especially useful. IR and NMR spectral data are in accord with a M2Rh2 bis(μ3-CO2) core for 2 and 3: they retain two μ3-[η1-C(M):η1-O(Rh):η 1-O′(Rh′)] carboxylate ligands that resemble those that were found for 1 and the Rh(I) carboxylates [(RCO2)Rh(diene)]2. Complexes 2 and 3 with their open-book structures are not fluxional at room temperature. Complex 2, its norbornadiene analogue, [Cp*(CO)2FeCO2Rh(η4-nbd)]2 (4), and their 13C-labeled derivatives also are accessible from reactions of Cp*(CO)2FeCO2K [or Cp*(CO)2-Fe13CO2K] with [Rh(OSO2CF3)(η4-cod)x. [Cp*(CO)2Fe(13CO2)Rh(η 4-diene)]2 [diene = cod (2-13C); nbd (4-13C)] underwent carboxylate-carbonyl label shuttle to yield 1:1 mixtures of [Cp*(CO)(13CO)FeCO2Rh(diene)]2 (2a-C13) and 4a-C13. IR spectral assignments for the metallocarboxylate νOCO absorptions are also presented.
A New Reaction Vessel for Accelerated Syntheses using Microwave Dielectric Super-heating Effects
Baghurst, David R.,Mingos, D. Michael P.
, p. 1151 - 1156 (1992)
Using a thick-walled glass reaction vessel a number of transition-metal organometallic and co-ordination compounds have been synthesised using microwave dielectric super-heating effects.Super-heating by 40-60 deg C is maintained by controlling the pressure at 10 atm and results in a decrease in the reaction time required for conventional reflux reactions by a factor of ca. 102.Full details of the design of the apparatus, the modification of a conventional microwave oven and the electrical circuitry for the pressure control are provided.
Rhodium complexes of a chelating bisphosphoniobenzophospholide cation
Haep, Stefan,Nieger, Martin,Gudat, Dietrich,Betke-Hornfeck, Michael,Schramm, Daniel
, p. 2679 - 2685 (2008/10/08)
The 1-(diphenyl(2-diphenylphosphinoethyl)phosphonio)-3-triphenylphosphoniobenzo[c]ph ospholide cation 1 reacts with [RhCl(C2H4)2]2 to form a dinuclear chelate complex, [RhCl(κ2-P(?2), P′(?)-1)]2 (5). Treatment of 5 with PPh3 affords mononuclear [RhCl(PPh3)(κ2- P(?2),P′(?3)-1)] (8), whereas reaction with 1,5-cyclooctadiene proceeds via cleavage of the Cl bridges to give [RhCl(cod)(κ-P(?3)-1)] (6). The chelating binding mode of 1 can be reconstituted by abstraction of chloride with TlOTf to give the dicationic complex [Rh(cod)(κ2-P(?2),P′(?3 )-1)]2+ (7). All complexes have been characterized by 1H, 31P, and 103Rh NMR spectroscopy, and 5[BPh4]2 was characterized as well by single-crystal X-ray diffraction. The structural parameters and metal NMR data confirm the different electronic properties of the two types of phosphorus centers in 1 and support in particular the assumption of distinct ?-acceptor character for the ?2-P atom, which should render the complexes potentially interesting precatalysts for hydroformylation. In accord with this hypothesis, complexes 5[BPh4]2 and 7[BPh4]2 display good activities and chemoselectivities as catalysts for the hydroformylation of 1-hexene at room temperature, even though the regioselectivities for n-aldehydes are low.
Reactions of [RhCl(diene)]2 with Bi- and terdentate nitrogen ligands. X-ray structures of five-coordinate complexes
Haarman, Hendrikus F.,Bregman, Frank R.,Ernsting, Jan-Meine,Veldman, Nora,Spek, Anthony L.,Vrieze, Kees
, p. 54 - 67 (2008/10/08)
Reaction of [RhCl(diene)]2 (diene = 1,5-cyclooctadiene (COD) or bicyclo[2.2.1] hepta-2,5-diene (NBD)) with the N-N-N nitrogen ligands 2,6-(C(R1)=N-R2)2C5H3N in CD2Cl2 or CH2Cl2 yielded the five-coordinate complexes [RhCl(2,6-(C(H)=N-R2)2C5H3N)(diene)] (diene = NBD; R2 = i-Pr, t-Bu, and p-anisyl), which has been isolated for NBD but not for COD. A single-crystal X-ray determination showed that [RhCl(2,6-(C(H)=N-p-anisyl)2C5H3N)(NBD)] has a distorted trigonal bipyramidal configuration with the pyridyl N-atom, one imine N-atom, and one alkene double bond in the equatorial plane, while the second alkene bond and the chloride atom occupy the axial positions. This conformation containing one noncoordinated imine moiety is clearly retained at 183 K in CD2Cl2, as is also the case for the other complexes. For the COD complexes, the reaction is more complicated, as the intermediates that are observed depend on the substituents R1 and R2 of the N-N-N nitrogen ligand. The five-coordinate complexes [RhCl(2,6-(C(R1)=N-R2)2C5H 3N)(COD)] could be observed at low temperatures for R1 = H and R2 = i-Pr, t-Bu, and p-anisyl, while for R1 = Me and R2 = p-anisyl, this intermediate could not be observed; instead, [Rh(2,6-(C(Me)=N-p-anisyl)2C5H3N) 2]+Cl- was found, which shows the presence of one N-N-N ligand bonded as a bidentate ligand and one N-N-N ligand bonded as a terdentate ligand at low temperatures. Further reaction of [Rh(2,6-(C(Me)=N-p-anisyl)2C5H3N) 2]+Cl- with [RhCl-(COD)]2 afforded [RhCl(2,6-(C(Me)=N-p-anisyl)2C5H3N)] and subsequently, via oxidative addition of CD2Cl2, the complex [RhCl2(CD2Cl)(2,6-(C(Me)=N-p-anisyl)2C 5H3N)]. The dynamic properties of the five-coordinate diene complexes [RhCl(2-(C(H)=N-R2)-6-(Me)-C5H3N)(NBD)] (R2 = i-Pr, t-Bu, and p-anisyl), which contain N-N nitrogen ligands, and of the new complexes [Rh(2-(C(H)=N-R2)-6-(Me)C5H3N)(NBD)]OTf (R2 = i-Pr, t-Bu, and p-anisyl) and of [Rh(2,2′-bipyrimidine)(NBD)]OTf have been investigated. A single-crystal X-ray determination of [RhCl(2-(C(H)=N-i-Pr)-6-(Me)C5H3N)(NBD)] showed structural features which are analogous to those of [RhCl(2,6-(C(H)=N-p-anisyl)2C5H3N)(NBD)].
Polyoxoanion-supported catalyst precursors. Synthesis and characterization of the iridium(I) and rhodium(I) precatalysts [(n-C4H9)4N]5Na 3[(1,5-COD)M·P2W15Nb3O 62] (M = Ir, Rh)
Pohl, Matthias,Lyon, David K.,Mizuno, Noritaka,Nomiya, Kenji,Finke, Richard G.
, p. 1413 - 1429 (2008/10/08)
The reaction of the triniobium-substituted polyoxometalate [(n-C4H9)4N]9P2W 15Nb3O62 with an equimolar amount of [Ir(1,5-COD)(CH3CN)2]BF4 or [Rh(1,5-COD)(CH3CN)2]BF4 (1,5-COD = 1,5-cyclooctadiene) leads to the formation of the air-sensitive polyoxometalate-supported organometallic complexes [(1,5-COD)IrP2W15Nb3O62] 8-, 1, and [(1,5-COD)Rh·P2W15Nb3O 62]8-, 2. These complexes were isolated as their mixed 5[(n-C4H9)4N]+/3Na+ salts and have been characterized by 1H, 13C, 31P, and 183W NMR spectroscopy as well as IR spectroscopy, sedimentation-equilibrium molecular-weight measurements, and complete elemental analyses. Additional studies of 1 by 17O NMR demonstrate that the iridium binds in overall average C3v (pseudo) symmetry to the Nb3O93- minisurface (pseudo due to the 2-fold axis in 1,5-COD and thus the local Cs symmetry at iridium). For 2, the results of the 17O NMR studies are definitive in showing that 2 can also be successfully 17O-enriched in the niobium-oxygen sites. However, the 17O NMR data subsequently acquired for 2 require the formulation of two or more (possibly rapidly interconverting) support-site isomers in solution. These 17O NMR results provide direct evidence for the M-ONb2 bonding between [(1,5-COD)M]+ (M = Ir, Rh) and P2W15Nb3O629- in solution, where catalysis beginning with 1 and 2 as a precatalyst has been demonstrated.
Synthesis of the Mixed-metal Clusters ; Reactions of > (R = Ph or Et) and Crystal Structure of 3-Au(PPh3)>>
Adatia, Trushar,Curtis, Hilary,Johnson, Brian F. G.,Lewis, Jack,McPartlin, Mary,Morris, Jill
, p. 3069 - 3074 (2007/10/02)
Treatment of the pentaruthenium salt 2 with an excess of (cod = cycloocta-1,5-diene) yielded the monoanion (1-) which has been isolated as its (1+) salt 1.Reaction of the monoanion with HBF4*Et2O gave the hydrido derivative 2.Compound 1 reacted with the gold salts Cl and Cl, respectively, to yield the cluster compounds > 3 and > 4.Compound 3 crystallises in the triclinic space group P (no. 2) with a = 15.993(3), b = 9.728(2), c = 13.900(3) Angstroem, α = 90.29(2), β = 99.97(2), γ = 88.36(2) deg.The metal core geometry consists of a central Ru5Rh octahedron with one Ru3 face capped by a μ3-Au(PPh3) fragment .The reactions of 3 and 4 with norbornadiene, PPh3 and P(OMe)3 are reported.
Steric effects of the 2-(diphenylphosphino)-6-methoxypyridine short-bite bridging ligand in the synthesis of binuclear complexes. Crystal and molecular structure of [Rh2Cu(CO)2(Ph2PPyOMe) 2(μ-Cl)2]BF4·CH2Cl 2
Arena, Carmela Grazia,Faraone, Felice,Lanfranchi, Maurizio,Rotondo, Enrico,Tiripicchio, Antonio
, p. 4797 - 4802 (2008/10/08)
Treatment of [Rh(COD)(μ-Cl)]2 (COD = cycloocta-1,5-diene) with 2-(diphenylphosphino)-6-methoxypyridine (Ph2PPyOMe) in benzene solution yielded the complex [Rh(COD)(Ph2PPyOMe)Cl] (1), in which Ph2PPyOMe acts as an η1 P-bonded ligand. The COD ligand was easily displaced when CO was bubbled into a CH2Cl2 solution of 1, and the presence in solution of cis-[Rh(CO)2(Ph2PPyOMe)Cl] (2) was established by IR and NMR spectroscopy. By the addition of Ph2PPyOMe to a CH2Cl2 solution containing 2 (molar ratio 1:1) or [Rh(CO)2(μ-Cl)]2 (molar ratio 4:1), trans-[Rh(CO)(Ph2PPyOMe)2Cl] (3) was obtained. The lack of formation in these reactions of the A-frame complex [Rh2(μ-CO)(Ph2PPyOMe)2Cl2], as was observed in the analogous reactions with 2-(diphenylphosphino)pyridine (Ph2PPy), is discussed. The reaction of 3 with [Cu(NCCH3)4]BF4, in CH2Cl2 solution, gave nearly quantitatively the complex [Rh2Cu(CO)2(Ph2PPyOMe) 2(μ-Cl)2]BF4·CH2Cl 2 (4), whose structure was established by an X-ray diffraction study. Attempts to obtain a Rh2Au complex, analogous to 4, failed. Crystals of 4 are monoclinic, of space group P21/a with Z = 4 in a unit cell of dimensions a = 32.852 (8) A?, b = 10.452 (4) A?, c = 12.945 (5) A?, and β = 97.17 (2)°. The structure was solved from diffractometric data by Patterson and Fourier methods and refined by full-matrix least-squares techniques on the basis of 4842 observed reflections to R and Rw values of 0.0500 and 0.0661, respectively. The cationic complex of 4 is a trinuclear Rh2Cu species containing two rhodium atoms linked by two bridging chloride ligands; the CO and the Ph2PPyOMe (P-bonded to Rh) ligands complete the coordination of each rhodium center. The two CO ligands are mutually trans. The copper center is almost linearly coordinated by the pyridine nitrogen atoms of the Ph2PPyOMe ligands. The copper and rhodium atoms are not involved in a metal-metal bond. The reaction of 1 with [AuPPh3]PF6 afforded [Rh(COD)(μ-C l)]2 and [Au(PPh3)(Ph2PPyOMe)]PF6 (6). Transfer of the Ph2PPyOMe ligand from one metal center to another occurred also in the reactions of 1 with cis-[Pd(CNtBu)2Cl2] and [Pd(COD)Cl2]. The reaction products were [Rh(CO)2(μ-Cl)]2 and respectively cis-[Pd(CNtBu)(Ph2PPyOMe)Cl2] (7) and [Pd(Ph2PPyOMe)Cl(μ-Cl)]2 (8), Ph2PPyOMe acting as an η1 P-bonded ligand in the last two. The effect of the small bite angle of the Ph2PPyOMe ligand on the pathway of these reactions is discussed, and a comparison with the results of analogous reactions of complexes containing the Ph2PPy ligand is made.
