Complexes of functional phosphines. 22. Cobalt(II) complexes with .beta.-keto phosphines and corresponding cobalt(III) enolates. Crystal and molecular structures of the fac and mer isomers of [Co{Ph2PCHC(O)Ph}3]

Braunstein, Pierre; Kelly, D. G.; Tiripicchio, António; Ugozzoli, Franco

doi:10.1021/ic00074a032

Cited by 23 publications

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“…Interestingly the NsH protons in the ligand (which were located by ∆F maps) are no longer syn with respect to the PdO Previous work has demonstrated that -ketophosphine metal complexes can be deprotonated to afford coordinated phosphino enolate ligands. [51][52][53][54][55][56] Using a suitable base (e.g. the metal alkoxide t BuOK) we find that the acidic proton of the bound HL ligand in the complexes 4 and 5 are readily removed, affording the bischelate complexes [M{Ph 2 PNP(O)Ph 2 -P,O} 2 ] [M ) Pt (10); M ) Pd (11)] (Scheme 2).…”

Section: Resultsmentioning

confidence: 99%

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Palladium(II) and Platinum(II) Complexes of the Heterodifunctional Ligand Ph₂PNHP(O)Ph₂

et al. 1996

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The noncomplexed ligand Ph 2 PNHP(O)Ph 2 (HL) has been prepared, for the first time, from Ph 2 PNHPPh 2 (dppa) and H 2 O 2 in moderate yield. On further treatment with H 2 O 2 the phosphine oxide Ph 2 P(O)NHP(O)Ph 2 (1) can be formed. Reaction of [MCl 2 (COD)] (M ) Pt or Pd; COD ) cycloocta-1,5-diene) with 2 molar equiv of HL affords [MCl 2 (HL) 2 ] (4, 5) in which both ligands are monodentate P-bound. The analogous dibromo and diiodo derivatives [MX 2 (HL) 2 ] (6-9) were prepared from either [MX 2 (COD)] (M ) Pt or Pd; X ) Br or I) and HL or treatment of [MCl 2 (HL) 2 ] with an excess of NaI. Facile base deprotonation of the amine proton in 4 or 5 affords a new class of metallacycles [M(L) 2 ] [L -) Ph 2 PNP(O)Ph 2 -] (10, 11) incorporating two five-membered M-P-N-P-O rings. Compound 10 was independently made from [Pt(CH 3 ) 2 (COD)] and 2 equiv of HL in toluene at ambient temperature whereas the reaction of [Pt(CH 3 )Cl(COD)] with 2 equiv of HL affords solely trans-[Pt-(CH 3 )Cl(HL) 2 ] (13). Protonation of the neutral compound 10 with HCl in ethanol regenerates the ring-opened cis complex 4. In contrast, addition of HBF 4 ‚OEt 2 to 10 (or 11) results in exclusive protonation at the nitrogen atom of the chelating ligands to give cis-[M{Ph 2 PNHP(O)Ph 2 -P,O} 2 ][BF 4 ] 2 (15, 16); both chelate rings remain intact. The dicationic compounds 15, 16 can also be synthesized from 4, 5 in dichloromethane using Ag[BF 4 ] as a chloride abstractor. All new compounds described have been characterized by a combination of multinuclear NMR spectroscopy, IR spectroscopy, and elemental analyses. The molecular structures of Ph 2 PNHP(O)Ph 2 , cis-[PtBr 2 {Ph 2 PNHP(O)Ph 2 -P} 2 ], cis-[Pt{Ph 2 PNP(O)Ph 2 -P,O} 2 ], trans-[Pt(CH 3 )Cl{Ph 2 PNHP(O)Ph 2 -P} 2 ] and cis-[Pt{Ph 2 PNHP(O)Ph 2 -P,O} 2 ][BF 4 ] 2 have been determined by single-crystal X-ray diffraction. Crystals of HL are triclinic, space group P1 h, with a ) 10.410(2) Å, b ) 12.083(2) Å, c ) 9.036(4) Å, R ) 103.05(2)°, ) 99.09-(2)°, γ ) 72.98(1)°, V ) 1054 Å 3 , and Z ) 2. The final R and R w values were 0.061 and 0.047, respectively. Crystals of 6 are triclinic, space group P1 h, with a ) 13.113(4) Å, b ) 15.996(4) Å, c ) 13.011(4) Å, R ) 102.65(3)°, ) 117.39(2)°, γ ) 101.03(2)°, V ) 2225 Å 3 , and Z ) 2. The final R and R w values were 0.039 and 0.031, respectively. Crystals of 10 are monoclinic, space group P2 1 /a, with a ) 17.600(13) Å, b ) 13.498-(10) Å, c ) 18.641(9) Å, ) 105.13(1)°, V ) 4274 Å 3 , and Z ) 4. The final R and R w values were 0.041 and 0.036, respectively. Crystals of 13 are triclinic, space group P1 h, with a ) 14.686(2) Å, b ) 18.735(2) Å, c ) 9.018(3) Å, R ) 91.71(2)°, ) 102.27(2)°, γ ) 68.54(1)°, V ) 2253 Å 3 , and Z ) 2. The final R and R w values were 0.041 and 0.044, respectively. Crystals of 15 are orthorhombic, space group P2 1 2 1 2, with a ) 14.100(2) Å, b ) 19.002(1) Å, c ) 9.145(2) Å, V ) 2450 Å 3 , and Z ) 2. The final R and R w values were 0.052 and 0.057, respectively. The P-bound monodentate complexes contain ligands with similar...

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Section: Resultsmentioning

confidence: 99%

“…Anal. Calcd (found) for C 48H42N2O2P4PtCl2: C,53.95 (53.25); H, 3.95 (3.85); N, 2.60 (2.85). Selected IR data (KBr): 3293, 3172 ν(NsH), 1217 ν(PdO), 315, 283 ν(PtsCl) cm -1 .…”

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confidence: 99%

Palladium(II) and Platinum(II) Complexes of the Heterodifunctional Ligand Ph₂PNHP(O)Ph₂

et al. 1996

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“…The discovery that certain nickel(I1) complexes incorporating mixed P,O donor ligands were effective catalyst precursors for ethylene oligomerization reactions in the so-called ShellHigher-Olefin-Process (SHOP) (1-7) has sparked a number of groups to devise new ancillary ligands that can be utilized (8)(9)(10)(11)(12)(13)(14). The original preparation (1) involved reaction of a ketophosphorus ylid of the type P h , P C H C O P h with Ni(COD), and PPh3 to produce, after phenyl transfer, the complex Ni(Ph)PPh,[Ph,PCH=C(O)Ph].…”

Section: Introductionmentioning

confidence: 99%

Coordination chemistry of a mixed donor bidentate ligand with nickel. A tetrameric enolate of sodium that binds a phosphine donor

Fryzuk¹,

Gao²,

Rettig³

1995

Can. J. Chem.

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The preparation of a mixed donor ligand consisting of an enolate and neutral phosphine is described and its coordination chemistry with nickel reported. The phosphino ketones R,PCH,COPh (R = Cy or Pri) are prepared by the reaction of the corresponding secondary phosphines with bromoacetophenone to form the corresponding phosphonium salts [R,P(H)CH,COPh]+Br-(R = Cy or Pi); subsequent deprotonation leads to the neutral ketones. The enolates are formed by addition of NaN(SiMe,), to the neutral ketone. The crystal structure of the sodium enolate having isopropyl substituents at phospho~us displays a tetrameric structure in the solid state and there is an interaction of the phosphorus donor with the sodium anion: Na-P, 2.852(2) A. The preparation of a series of nickel complexes was achieved by addition of the sodium enolate to the appropriate Ni(I1) starting material. The structures of the nickel derivatives are reported. The catalytic behaviour of one of these complexes in the polymerization and oligomerization of ethylene is briefly described. ' Author to whom correspondence may be addressed. Telephone: (604)

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“…Similar behavior has been observed with P,O-chelated Co(III) complexes. [41] Further confirmation of the different oxidation states in the series of complexes 3a-3d was obtained from electrochemical measurements (Figure 1). The profiles for complexes 3a and 3b drastically differ from those of complexes 3c and 3d and show an irreversible oxidation above 2 V, while the latter feature a partially reversible redox process around 0.8 V vs. Ag/ AgCl (Table 1).…”

Section: Synthesis and Characterization Of Triazolylidene Cobalt Comp...mentioning

confidence: 65%

Mesoionic Carbene Cobalt Complexes as Multipurpose Catalyst Precursors for Hydrosilylation and Dihydropyrimidinone Synthesis

Bertini

Albrecht

2021

Helvetica Chimica Acta

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Metalation of CH 2 OH-substituted triazolium salts with CoCl 2 under basic conditions affords C,O-bidentate chelating carbene Co(III) complexes (3a, 3b), while analogous phenyl-substituted triazolium salts produce monodentate carbene Co(II) complexes (3c, 3d). The distinct substituent-induced properties of the metal centers were demonstrated by electrochemical measurements and catalytic activities in two specific processes. The complexes showed appreciable activity in the reduction of C=O bonds through hydrosilylation, with methoxybenzene-functionalized triazolylidene Co(III) complex 3a achieving a high selectivity towards aldehydes vs. ketones with turnover frequencies (TOFs) up to 200 h À 1 . The C,O-chelate systems were also active catalysts in the Biginelli process, a one-step three-component reaction for efficient dihydropyrimidinone synthesis. Optimization of reaction conditions provides high activity with complex 3a, reaching TOFs of 800 h À 1 , the highest activity known for cobalt NHC complexes to date.

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Complexes of functional phosphines. 22. Cobalt(II) complexes with .beta.-keto phosphines and corresponding cobalt(III) enolates. Crystal and molecular structures of the fac and mer isomers of [Co{Ph2PCHC(O)Ph}3]

Cited by 23 publications

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Palladium(II) and Platinum(II) Complexes of the Heterodifunctional Ligand Ph₂PNHP(O)Ph₂

Palladium(II) and Platinum(II) Complexes of the Heterodifunctional Ligand Ph₂PNHP(O)Ph₂

Coordination chemistry of a mixed donor bidentate ligand with nickel. A tetrameric enolate of sodium that binds a phosphine donor

Mesoionic Carbene Cobalt Complexes as Multipurpose Catalyst Precursors for Hydrosilylation and Dihydropyrimidinone Synthesis

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Complexes of functional phosphines. 22. Cobalt(II) complexes with .beta.-keto phosphines and corresponding cobalt(III) enolates. Crystal and molecular structures of the fac and mer isomers of [Co{Ph2PCHC(O)Ph}3]

Cited by 23 publications

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Palladium(II) and Platinum(II) Complexes of the Heterodifunctional Ligand Ph2PNHP(O)Ph2

Palladium(II) and Platinum(II) Complexes of the Heterodifunctional Ligand Ph2PNHP(O)Ph2

Coordination chemistry of a mixed donor bidentate ligand with nickel. A tetrameric enolate of sodium that binds a phosphine donor

Mesoionic Carbene Cobalt Complexes as Multipurpose Catalyst Precursors for Hydrosilylation and Dihydropyrimidinone Synthesis

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Palladium(II) and Platinum(II) Complexes of the Heterodifunctional Ligand Ph₂PNHP(O)Ph₂

Palladium(II) and Platinum(II) Complexes of the Heterodifunctional Ligand Ph₂PNHP(O)Ph₂