Cyclometalation at carbon adjacent to oxygen in platinum(II) and iridium(I) phosphine complexes

Heating trans-PtCl₂(t-Bu₂PCH₂OCH₃)₂ at 125°C in 2-methoxyethanol yields a cyclometalated derivative, P$\text{tCl(t-Bu}{}_2\text{PCH}{}_2\text{OCH}$₂)(t-Bu₂PCH₂OCH₃). Adding excess NaI and 1,8-bis(dimethylamino)naphthalene accelerates the reaction and gives the iodide-substituted analog. Under the same conditions, trans-PtCl₂(t-Bu₂POCH₂CH₃)₂ is also metalated at the methyl carbon atom. However, the slower rate of this reaction indicates that an α-oxygen atom has an electronic accelerating effect on the metalation process. Neither t-Bu₂POCH₃ nor t-Bu₂PCH₂CH₂OCH₃ give platinum(II) cyclometalated complexes; four- or six-membered chelate ring formation appears to be unfavorable. The t-Bu₂PCH(CH₃)OCH₃ ligand also does not yield a platinum(II) metalated derivative. However, [IrCl(COT)₂]₂ (COT = cyclooctene) reacts at 25°C with both t-Bu₂PCH₂OCH₃ and t-Bu₂PCH(CH₃)OCH₃, to form iridium(III) metalated complexes by oxidative addition to the methyl CH bond. These coordinatively unsaturated compounds react with CO, yielding octahedral iridium(III) carbonyl hydride complexes.     

Some partially fluorinated cyclic and acyclic compounds of sulphur (II) and (IV) and partially fluorinated cyclic compounds of phosphorus (III) and (V)

Sulfinyl fluoride and N-(F-isoprophyl)iminosulfur difluoride form the compounds, O$\text{SN(CH}{}_3\text{)CH}{}_2\text{CH}{}_2\text{N}$(CH₃) and i-C₃F₇N$\text{SN(CH}{}_3\text{CH}{}_2\text{CH}{}_2\text{N}$(CH₃ with symdimethylethylenediamine (1). In contrast, CF₃C(O)NSF₂ and (R_f)₂SF₂ (R_f = CF₃, i-C₃F₇ form only acyclic compounds, CF₃C(O)N(CH₃)CH₂CH₂N(CH₃)C(O)CF₃ and R_fSN(CH₃)CH₂CH₂N(CH₃)SR_f with (1). With PF₃, PF₅ and OPF₃, cyclic compounds $\text{N(CH}{}_3\text{)CH}{}_2\text{CH}{}_2\text{N(CH}{}_3\text{)P}$F, $\text{N(CH}{}_3\text{)CH}{}_2\text{CH}{}_2\text{N(CH}{}_3\text{)P}$F₃, and $\text{N(CH}{}_3\text{)CH}{}_2\text{CH}{}_2\text{N(CH}{}_3\text{)P}$-(O)F result. When the latter two compounds are reacted further with LiNC(CF₃)₂, N(CH₃)CH₂CH₂N(CH₃)PF₂NC(CF₃)₂ and $\text{N(CH}{}_3\text{CH}{}_2\text{CH}{}_2\text{N(CH}{}_3\text{)P}$(O)NC(CF₃)₂) form.     

Metallorganische verbindungen des iridiums und rhodiums: XXVI. CH-metallierung und hydridbildung im system Ir2Cl2(C8H14)4/PR3(PR3 = P(CH2CMe3)3, t-BuP(CH2CMe3)2, t-Bu2PCH2CMe3; i-Pr3P

Treatment of Ir₂Cl₂(C₈H₁₄)₄ with the phosphines t-Bu_3?nP(CH₂CMe₃)_n (n = 3,2,1) in hot toluene followed by crystallization of the products from C₇H₈/ EtOH mixtures gave the cyclometallated hydrides (C₈H₁₄)₂Ir-μ-Cl₂$\text{IrH[CH}{}_2\text{CMe}{}_2\text{CH}{}_2\text{P}$(CH₂CMe₃)₂][P(CH₂ (I) [t-BuP(CH₂CMe₃)₂]₂H₂Ir-μ-Cl₂$\text{IrH[CH}{}_2\text{CMe}{}_2\text{CH}{}_2\text{P}$Bu^t(CH₂CMe₃)][t-BuP(CH₂CMe₃)₂] (II), and [(t-Bu₂$\text{PCH}{}_2\text{CMe}{}_2\text{CH}{}_2\text{)HI}$rCl]₂ (III). The dihydrides IrH₂Cl[t-BuP(CH₂CMe₃)₂]₂ (IIa) and IrH₂Cl(t-Bu₂PCH₂CMe₃)₂ (IIIa) were also isolated; these species were, however, more conveniently obtained by bubbling hydrogen through the solution of Ir₂Cl₂ (C₈H₁₄)₄ and the respective phosphine in toluene. i-Pr₃ reacted with the olefiniridium(I) precursor in C₇H₈/EtOH to yield the carbonyl complexes (i-Pr₃P)₂H₂Ir-μ-Cl₂Ir(CO)(PPrⁱ₃)₂ (IV) and IrCl(CO)(PPⁱ₃)₂ (IVa), no cyclometallated product being detected. The stereochemistries of the complexes were deduced from IR, ¹H, ³¹P, and ¹³C NMR data. The crystal structures of IIIa and IVa were also determined.     

Reactions of hydridosilacyclobutanes with low-valent complexes of iron or platinum

Unstable transition metal compounds formed from hydridosilacyclobutanes are described: 1-methyl-1-silacyclobutane reacts with nonacarbonyldiiron to give the complexes [Fe(CO)₄(H){$\text{Si(Me)CH}{}_2\text{CH}{}_2\text{C}$H₂}] and [$\text{Fe{CH}{}_2\text{CH}{}_2\text{CH}{}_2\text{Si}$(H)Me}(CO)₄], and with bis(triphenylphosphine)(ethylene)platinum(0) to give [Pt(H)(PPh₃)₂{$\text{Si(Me)CH}{}_2\text{CH}{}_2\text{C}$H₂}].     

Darstellung und eigenschaften von und Reaktionen mit metallhaltigen Heterocyclen: X. Untersuchungen über den Ablauf der heterolytischen Spaltung der ReRe-Bindung bei der Darstellung von Rhenacycloalkanen; Grenzen ihrer Stabilität und SO2-Insertion in die ReC-σ-Bindung

The six- and seven-membered rhenacycloalkanes (OC)₄R$\text{ePR}{}_2\text{OCH}{}_2\text{XC}$H₂ (R = CH₃, C_oH₅; X = CH₂, CH₂CH₂) are obtained by reaction of the binuclear anions [(OC)₄RePR₂O]₂^2? with the alkanediylbis(triflouromethanesulfonates) X(CH₂Y)₂ (Y = CF₃SO₂O) in dimethoxyethane. In the Reσ bond of (OC)₄R$\text{ePPh}{}_2\text{OCH}{}_2\text{CH}{}_2\text{C}$H₂SO₂ can be inserted under ring expansion. The rhenacycloheptanes (OC)₄R$\text{PR}{}_2\text{OCH}{}_2\text{CH}{}_2\text{CH}{}_2\text{C}$H₂ (R = CH₃, C_oH₅) are thermally unstable and decompose by cleavage of the α-CC bond. The heterolytic cleavage of the ReRe bond in [(OC)₄RePR₂O]₂^2? results in the open chain, ionic intermediate products [R₂(O)PRe(CO)₄CH₂XCH₂Y]^?, which in competition with the cyclisation, are liable to a β-hydrogen transfer. The mechanisms which are responsible for the formation of the hdrido complexes [HRe(CO)₄PR₂O]^? and HRe(CO)₄PR₂OCH₂XCH₃, are discussed.     

Intramolecular metalation of PBut2Ph and PBut3 in palladium acetate complexes

Reaction of [PdCl₂(PBu^t₂Ph)]₂ with silver acetate gives the internally metalated complex [P$\text{dCH}{}_2\text{CMe}{}_2\text{P}$Bu^tPh]₂(μ-Cl)₂. This reacts with TlC₅H₅ and LiC₅Me₅ with chloride-bridge cleavage to yield C₅R₅P$\text{dCH}{}_2$PBu^tPh (R = H, Me). The complex [P$\text{dCH}{}_2\text{CMe}{}_2\text{P}$Bu^t₂]₂(μ-Cl)₂,prepared from [PdCl₂(PBu^t₃)]₂ and CH₃COOAg, is analogously converted into C₅R₅$\text{PdCH}{}_2\text{CMe}{}_2\text{P}$Bu^t₂. The chloride complex C₅H₅Pd(PBu^t₅Ph)CI does not eliminate HCl to form C₅H₅P$\text{dCH}{}_2\text{CMe}{}_2\text{P}$Bu^tPh.     

Darstellung und eigenschaften von und reaktionen mit metallhaltigen heterocyclen: XXV. Synthese und eigenschaften neuer platina- und rhodacycloalkane durch substitution und oxidative addition einer CCl-bindung

The platinacyclopentane derivative [Cl(CH₂)₃R₂P](Cl)$\text{PtPR}{}_2\text{CH}{}_2\text{CH}{}_2\text{CH}{}_2$ is formed by action of Cl(CH₂)₃PR₂ on Pt(COD)₂ in n-hexane via the not isolable Pt[PR₂(CH₂)₃Cl]₂ (R  C₆H₁₁) by oxidative addition of a CCl bond to platinum. [μ-CIRh(CO)₂]₂ reacts in benzene with Cl(CH₂)₃PR₂ under partially CO substitution to give the stable intermediate Cl(OC)Rh[PR₂(CH₂)₃Cl]₂. In boiling toluene oxidative addition of a CCl bond to rhodium occurs under formation of the phospharhodacyclopentane [CI(CH₂)₃R₂P] Cl₂(OC)-$\text{RhPR}{}_2\text{CH}{}_2\text{CH}{}_2\text{CH}{}_2$ (R  C₆H₅). The ³¹P{¹H}-NMR spectra of the rhodium compound is characterized by an ABX system, that of the platinum by superposition of an ABX pattern with an AB spectrum.     

Unusual route to and rearrangement of four-membered ring complexes C5H5Fe (CO) [ (C6H5)2PN(R)CH (C6H5) ]

The amine substituted phosphines (C₆H₅)₂PN(H)CH₂CH₃ and (C₆H₅)₂PN(H)CH₂C₆H₅ react with C₅H₅Fe(CO)₂CH(C₆H₅) (OCH₃) photolytically to give moderate yields of the four-membered chelate ring complexes C₅H₅$\text{Fe (CO) [(C}{}_6\text{H}{}_5\text{)}{}_2\text{PN (CH}{}_2\text{CH}{}_3\text{) C}$H (C₆H₅)] and C₅H₅$\text{Fe (CO) [(C}{}_6\text{H}{}_5\text{)}{}_2\text{PN (CH}{}_2\text{C}{}_6\text{H}{}_5\text{)C}$H(C₆H₅)], respectively. Photolysis of C₅H₅Fe(CO)₂CH(C₆H₅) (OCH₃) in the presence of (S)-(?)-diphenyl(1-phenylethylamino)phosphine leads to the isolation of C₅H₅Fe(CO)[(C₆H₅)2PNC(CH₃) (C₆H₅)]CH₂C₆H₅ which is proposed to arise from a formally 1,3-hydrogen shift rearrangement of an intermediate four-membered chelate ring complex.     

Reactions and properties of some trimethyleneplatinum(IV) complexes: V. The kinetics and mechanism of formation from arylcyclopropanes

The kinetics of the reaction of arylcyclopropanes (4-XC₆H₄C₃H₅, X = H, Me, EtO) with either [Pt₂Cl₂(μ-Cl)₂(C₂H₄)₂] or [{$\text{PtCl}{}_2\text{(CH}{}_2\text{CH}{}_2\text{C}$H₂)} in tetrahydrofuran to give in each case [{$\text{PtCl}{}_2\text{(CHArCH}{}_2\text{C}$H₂)}₄] and ethylene or cyclopropane, respectively, have been studied. The reactions are essentially first order in both arylcyclopropane and platinum complexes. The order of reactivity follows the series X = EtO > > Me > H, and [Pt₂Cl₂(μ-Cl)₂(C₂H₄)₂]> [{$\text{PtCl}{}_2\text{(CH}{}_2\text{CH}{}_2\text{C}$H₂)}4] and the rate is accelerated in polar solvents. Mechanisms in which the arylcyclopropane first coordinates to platinum and then undergoes ring opening reactions are proposed.     

The photodecomposition of platinacycloalkanes in solution: II. 1,4-butanediylplatinum(II) and (IV) compounds

The products of the photolysis of a number of platinacyclopentanes in solution at 25°C under a variety of conditions have been determined. With [I₂P$\text{tCH}{}_2\text{CH}{}_2\text{CH}{}_2\text{C}$H₂(L₂)] (L = PMe₂Ph, PPh₃) in CH₂Cl₂, CH₂Br₂ and (CH₃)₂SO the hydrocarbon products are exclusively ethylene and but-1-ene. Formation of the latter through a 1,3-hydrogen shift is preceded by phosphine ligand dissociation. The photolysis of [ICH₃P$\text{tCH}{}_2\text{CH}{}_2\text{C}$H₂(L₂)] gave methane, ethylene, but-1-ene and n-pentane together with a little n-butane, the methane being formed from internal hydrogen abstraction by the CH₃ group in the excited reactant molecule. Photodecomposition of the platinum(II) compounds [P$\text{tCH}{}_2\text{CH}{}_2\text{CH}{}_2\text{C}$H₂(L₂)] (L = (PMe₂Ph)₂, (PPh₃)₂, Ph₂PCH₂CH₂PPh₂) gave ethylene, but-1-ene, pent-1-ene (with the halogenated solvents) and with some systems appreciable yields of n-butane, the latter being the results of internal abstraction of two hydrogen atoms by the C₄H₈ moiety. The formation of pentene is probably preceeded by the addition of CH₂Cl₂ or CH₂Br₂ to the excited reactant molecule. Addition of diphenylphosphine promotes the production of n-butane.     

Carbonyl complexes of manganese(I) with chelating phosphino-alkyl or -acyl ligands. Crystal and molecular structure of [Ph2PCH2CH2(O)CMn(CO)2(dppm)l

The phosphine Ph₂PCH₂CH₂Cl reacts with fac-[XMn(CO)₃(dppm)] (X = Cl or Br) in refluxing toluene to give the complexes cis,cis-[XMn(CO)₂(dppm)(Ph₂PCH₂CH₂Cl)] (I). Treatment of those species with Na amalgam in THF leads to the alkyl complex [Ph₂$\text{PCH}{}_2\text{CH}{}_2\text{M}$n(CO)₂(dppm)] (II), which does not react with CO under normal conditions but can be converted into cis,cis-[ClMn(CO)₂(dppm)(PPh₂Et)] by reacting with HCl (g) in ether. If the reduction of I with Na/Hg is carried out in the presence of CO the compound cis-[Ph₂$\text{PCH}{}_2\text{CH}{}_2\text{(O)CM}$n(CO)₂(dppm)] (III) is obtained. The latter has also been prepared directly from fac-[BrMn(CO)3(dppm)], Ph₂PCH₂CH₂Cl, and Na/Hg in THF, and characterized by X-ray crystallography. The crystals are monoclinic, space group P2₁/n; refinement gave R = 0.053 for 2593 reflections with I ? 2.5σ(I). The reaction of the complex fac-[O₃ClOMn(CO)₃(dppm)] with Ph₂PCH₂CH₂Cl in Cl₂CH₂ gives the salt fac-[Mn(CO)₃(dppm)(Ph₂PCH₂CH₂Cl)]ClO₄ which isomerizes to mer-[Mn(CO)₃(dppm)(Ph₂PCH₂CH₂Cl)]ClO₄ in boiling butanol. Both cationic carbonyl complexes give the acyl species III upon reduction with Na amalgam.     

The preparation and catalytic hydroformylation activity of some halocarbonylrhodium(I) complexes containing phosphinoalkylorganosilicon ligands

The synthesis and properties of a series of trans-halocarbonylrhodium(I) complexes containing the phosphinoalkylorganosilicon ligands Me₃SiCH₂PPh₂, Me₃Si(CH₂)₃PPh₂, and PPh₂CH₂(Me)$\text{Si(OSiMe}{}_2\text{)}{}_3\text{O}$ have been investigated. The complexes could be prepared by an exchange reaction involving RhCl(CO)(PPh₃)₂ and the organosilicon ligands or in better yields by the reaction of Rh₂Cl₂(CO)₄ with the ligands. Iodorhodium derivatives were obtained as the exclusive products in the latter reaction if a small amount of LiI was present. The catalytic activity of RhCl(CO)(PPh₂CH₂SiMe₃)₂ was similar to that of RhCl(CO)(PPh₃)₂ in the hydroformylation of hex-1-ene at 100°C and 1000 psi pressure of H₂/CO. The catalytic properties of the iodo derivatives RhI(CO)L₂ [L = Me₃SiCH₂PPh₂, Me₃Si(CH₂)₃PPh₂, and PPh₂CH₂(Me)$\text{Si(OSiMe}{}_2\text{)}{}_3\text{O}$] varied considerably, with RhI(CO)(PPh₂CH₂SiMe₃)₂ producing an unexpectedly low linear/branched aldehyde product ratio.     

Reactivite d'alcynes fluores vis-a-vis de methylthiolates [(η5-C5H5)M(SMe)(CO)3] et d'hydrures [(η5-C5H5)MH(CO)3] de molybdene et de tungstene

The electron deficient acetylene, hexafluorobut-2-yne, reacts with molybdenum and tungsten methanethiolate derivatives (prepared in situ) to give vinyl and three-, five-, or six-membered heterocyclic derivatives: [Cp(OC)- $\text{MoC(O)C(CF}{}_3\text{)C(CF}{}_3\text{)C(O)S}$Me], [Cp(OC)₂$\text{MC(CF}{}_3\text{)C(CF}{}_3\text{)C(CF}{}_3\text{)C(O)S}$Me], [CpW(CO)₃C(CF₃C(CF₃)SMe], [CpW{η³-$\text{C(CF}{}_3\text{)C(CF}{}_3\text{)C(SMe)OC}$(O)}-(CO)₂]. These reactions contrast with those of trifluoropropyne where no organometallic species are obtained. On heating or irradiation with CF₃CCCF₃ [CpMH(CO)₃] gives known bridged species and in the presence of dimethyl disulphide the vinyl derivative [CpM(CO)₃C(CF₃)C(CF₃)H]and an isomer of undetermined structure.     

Reactions and properties of some trimethyleneplatinum(IV) complexes: VII. Kinetics and mechanism of displacement of cyclopropane by alkenes

The kinetics of the reaction of alkenes (e.g. cis-pent-2-ene, hex-1-ene, cyclopentene) with [$\text{PtX}{}_2\text{(CH}{}_2\text{CH}{}_2\text{C}$H₂)(THF)₂] (X = Cl or Br, THF = tetrahydrofuran) or with [$\text{PtCl}{}_2\text{(CHPhCH}{}_2\text{C}$H₂)(THF)₂] in THF solution have been studied. The reactions occur with displacement of cyclopropane or phenylcyclopropane to give [PtCl₂(olefin)(THF)], and follow essentially second order kinetics, first order in both platinum complex and olefin. The mechanism of reaction is discussed.     

Perfluorocycloalkyl(aryl) diazenes from heptafluoronitrosocyclobutane and nonafluoronitrosocyclopentane

The perfluoronitrosocycloalkanes, heptafluoronitrosocyclobutane and nonafluoronitrosocyclopentane, are convenient precursors to a family of new perfluorocycloalkyl(aryl) diazenes. With aniline and o-aminobenzamide, $\text{CF}{}_2\text{(CF}{}_2\text{)}{}_{\mathrm{x}}\text{C}$FNN$\text{C(CH)}{}_4\text{C}$H and $\text{CF}{}_2\text{(CF}{}_2\text{)}{}_{\mathrm{x}}\text{C}$FNN$\text{C(CH)}{}_4\text{C}$C(O)NH₂ (x = 2,3) are formed. Additionally, heptafluoronitrosocyclobutane gives $\text{CF}{}_2\text{(CF}{}_2\text{)}{}_2\text{C}$FNN$\text{CCFCFCHCFC}$F and $\text{CF}{}_2\text{(CF}{}_2\text{)}{}_2\text{C}$FNN$\text{C(CH)}{}_4\text{C}$NH₂ with 2,3,5,6-tetrafluoroaniline and o-phenylenediamine     

Transition metalcarbon bonds: LV. Cyclometallation and other reactions of PBut2Bui and PPh2Bui with platinum(II) and palladium(II)

The new phosphine, PBu^t₂Buⁱ (L), was prepared from Bu^t₂PCl and LiBuⁱ. PPh₂Buⁱ (L′) was prepared from Ph₂PCl and LiBuⁱ. Treatment of [PtCl₂(NCBu^t)₂] with L′ gives [PtCl₂L′₂] which does not cyclometallate even on prolonged boiling in 2-methoxyethanol. In contrast, [PtCl₂(NCBu^t)₂] reacts with PBu^t₂Buⁱ in boiling 2-methoxyethanol to give the cyclometallated complex [$\text{Pt}{}_2\text{Cl}{}_2\text{(PBu}{}^{\mathrm{t}}{}_2\text{CH}{}_2\text{-CHMeCH}$₂)₂] (II, X = Cl). The corresponding bromide, iodide and acetylacetonate were prepared. With PPh₃ II (X = Cl) gives [$\text{PtCl(PBu}{}^{\mathrm{t}}{}_2\text{CH}{}_2\text{CHMeCH}$₂)(PPh₃)] which with NaBH₄ gives [$\text{PtH(PBu}{}^{\mathrm{t}}{}_2\text{CH}{}_2\text{CHMeC}$H₂)(PPh₃)]. Na₂PdCl₄ with L (2 mol equivalents) gave trans-[PdCl₂L₂], which was converted into trans-[Pd(NCS)₂-L₂] by metathesis with KSCN. Treatment of Na₂PdCl₄ with L (1 mol equivalent) gave [Pd₂Cl₄L₂], which on heating in 2-methoxyethanol gave [$\text{Pd}{}_2\text{Cl}{}_2\text{(PBu}{}^{\mathrm{t}}{}_2\text{CH}{}_2\text{-CHMeCH}$₂)₂], as a mixture of syn- and anti-isomers. The complexes trans-[PdCl₂-L′₂] and [Pd₂Cl₄L′₂] were also prepared. ¹H- and ³¹P NMR data are given.     

Cumulative subject index: vol. 176 (1979)–200 (1980)

Electron deficient CpTiCl₃ reacts with the bis-alkoxide CpCl$\text{TiOCMe}{}_2\text{CMe}{}_2\text{O}$ to produce the diolato dimer (CpTiCl₂)OCMe₂CMe₂O(TiCl₂Cp). CpTiCl₃ reacts with Cp₄Ti₄Cl₄(μ₂-O)₄, which also has two oxo ligands on each titanium atom, to produce [CpTiCl₂]₂O. These and other redistribution reactions indicate that destabilization results from internal competition for metal d-orbitals by strong π-donor (e.g. alkoxide) ligands. Equilibrium constants for the formation of the η²-acetyl complexes Cp₂Zr[C(O)Me]X by Co insertion into Cp₂ZrMeX decrease in the order X = Me>Cl>OEt. This reflects internal competition of π-donor orbitals on X with the oxygen donor orbital in the η²-acetyl functionally. The significance of this effect for Fischer-Tropsch syntheses in both homogeneouus and heterogeneous media is discussed.     

The vapor-pressure isotope effect for (CH3)2CO and (CD3)2CO from 206 to 333 K

Isotopic vapor-pressure differences between (CH₃)₂CO and (CD₃)₂CO have been measured by differential capacitance manometry. When combined with available absolute vapor pressures for (CH₃)₂CO the results may be expressed (206 to 333 K) as:

$\text{1n}\text{(}\text{p}{}_{\mathrm{H}}\text{p}{}_{\mathrm{D}}\text{) = 3642.6(K/T)}{}^2\text{? 22.205(K/T) + 0.01129}$