Reaction of diarylzinc compounds with copper(I) salts. Synthesis and characterization of arylcopper(I) compounds

The reaction of diarylzinc compounds with copper(I) salts is an excellent way of preparing stable arylcopper compounds in quantitative yields. These compounds have been characterized by IR, and by ¹H and ¹³C NMR spectroscopy. Cryoscopic molecular weight determinations show phenylcopper to be polymeric and 2-methylphenylcopper and 2,6-dimethylphenylcopper to be tetrameric in benzene. The compounds are believed to contain aryl groups bridging two copper atoms. Evidence is presented for rotation of these aryl groups around the C(1)—C(4) axis.     

Intramolecular dynamics of 3c2e bonded aryl groups in polynuclear aryl-copper, -silver and -gold derivatives

Dynamic ¹H and ¹³C NMR studies reveal that the prochiral methylene group in 2-(Me₂NCH₂)C₆H₄-metal compounds R₄M₂Li₂ (M = Cu, Ag or Au) is an excellent probe for the monitoring of the configuration at C(1) in each of the 2-(Me₂NCH₂)C₆H₄MLi units. In this way the rotation of 3c2e bonded aryl groups around the C(1)?C(4) axis has been unambiguously establish for the first time. Chiral labelling of the 3c2e bonded group provides information concerning the stereochemistry of the R₄M₂Li₂ cluster.     

Aromatic lead(IV) compounds : VIII. 13C FT-NMR spectroscopy of compounds Arn Pb(CH3)4−n (n = 0–4)

¹³C chemical shifts and ²⁰⁷Pb¹³C coupling constants are reported for some arylmethyllead compounds. The value of J(²⁰⁷Pb¹³C) is shown to depend on the number and the nature of the aryl groups.     

The regio- and stereospecific synthesis of diarylpropenyllithium compounds from dimethylamino- and dimethylaminomethyl-substituted diarylacetylenes via transmetallation reactions involving diarylpropenylmagnesium and -tin compounds

Dimethylamino- and dimethylaminomethyl-substituted diarylacetylenes were prepared by the Pd(PPh₃)₄-catalyzed coupling reaction of dimethylamino- and dimethylaminomethyl-substituted aryl halides with arylacetylenes.Reaction of the asymmetric diarylacetylenes with methylmagnesium bromide in the presence of NiCl₂(PPh₃)₂ gave stereo- and regio-selectively cis addition products in which the aryl group bearing the built-in ligand (Me₂N or Me₂NCH₂) and the magnesium atom are bonded to the same unsaturated carbon atom. The E-diarylpropenylmagnesium bromides were converted in two successive transmetallation steps into the corresponding E-triphenyltin and Z-lithium compounds with retention of configuration. Depending on the type of solvent, complete inversion of configuration was observed for the Z-diarylpropenyllithium compounds. From the E-lithium compounds the corresponding Z-diarylpropenyltriphenyltin compounds were prepared (Scheme 1).Retention of configuration in the series of transmetallation reactions has unambiguously been established by comparison of the ¹¹⁹Sn¹H, ¹³C¹H and ¹¹⁹Sn¹³C coupling constants observed in the ¹H and ¹³C NMR spectra of the configurationally pure stereoisomeric pairs.     

Perfluoro organic compounds of silver

Non fluorinated organo silver compounds are thermally unstable. In contrast fluorinated organo silver compounds are thermally more stable, the stability increasing with perfluoro aromatic counterparts rather than perfluoro aliphatic systems.The synthesis of pentafluorophenyl silver can be done by several methods:

Similar results are obtained using complexes of silver pentafluorobenzoate with α, α′-Dipyridyl or o-phenanthroline as starting compounds.The C₆F-Ag-compounds react as C₆F₅-transferring systems. Their structur seems to consist of clusters, the highest mass number found corresponding to [Ag₄(C₆F₅)₃]⁺. On thermal degradation [Ag₂C₆F₅]_n seems to be formed.Increased thermal stability is shown by Paratetrafluorophenylene disilver, which is formed by decarboxylation of silver tetrafluoro terephthalate. Although insoluble in organic solvents it can be reacted in suspension yielding 1,4 derivatives of tetrafluorobenzene. All complexes of silver tetrafluoro phthalate are degraded during decarboxylation with the formation of Para-tetrafluorophenylene disilver.     

Preparation and some reactions of organogermylmercuryplatinum complexes and related compounds

A single-crystal X-ray diffraction study of tetracarbonyl-ferra-3-cyclopentene-2,5-dione has been made. Formally the compound can be derived from maleic anhydride by substitution of the bridging oxygen by Fe(CO)₄. Accordingly the bonding character is similar to that of maleic anhydride. The ironcarbon distances in the ring indicate partial double bonds. The octahedrally coordinated iron atom is linked to four terminal carbon monoxide ligands, with a longer bond distance to the equatorial than to the axial ones (FeC_ax 1.809 Å, FeC_eq 1.854 Å). The axial CO groups are strongly inclined towards the ring (C_axFeC_ax 164°). The latter effect is explained by electronic repulsion of the CO groups.IR, ¹H NMR, and ¹³C NMR data are reported. Crystal data: space groupPnama:α  12.708(10),b  10.058(7),c  7.527(5) Å;Z  4. With 625 reflections [F_o > 3o(F_o)] the structure has been refined anisotropically (hydrogen isotropically) to R0.022.     

Alkylidentriphenylphosphoran-komplexe von kupper(I)- und silber(I)-chlorid: I. 21 komplexe

Ylide complexes of the type [(C₆H₅)₃PCHRMCHRP(C₆H₅)₃]Cl (M = Cu, Ag) have been obtained from the reaction of methylene, ethylidene- and isobutylidene-triphenylphosphorane with CuCl and AgCl. These organocopper and organosilver compounds are of surprisingly high thermal stability. In the ¹H, ¹³C and ³¹P NMR spectra of the silver compound (R = H) the spin—spin interactions ¹HC^107,109 Ag, ³¹PC^107,109 Ag, and for the first time, ¹³C^107,109 Ag could be detected.     

Synthese d'ethers et de thioethers allyliques fluores par catalyse par transfert de phase

Several fluorinated allylic ethers, thioethers and diethers have been prepared in excellent yields by phase transfer catalysis (CTP). The used halogenated compounds are allyl chloride and bromide, p-chloromethylstyrene. The used fluorinated alcohols are aromatic pentafluorophenol and various aliphatics: CF₃CH₂OH, CF₂HCF₂CH₂OH ClCF₂CF₂CH₂OH,C₆F₁₃C₂H₄OH, HOCH₂CF₂CFClCF₂CH₂OH and HOC₆H₄C(CF₃)₂C₆H₄OH. All these new compounds have been characterized by ¹H and ¹³C NMR. We conclude that CTP is the best method to obtain allylic and diallylic compounds.     

Bis(fluorbenzoyloxy)methylphosphanoxide

Bis(fluorbenzoyloxy)methyl phosphane oxides CH₃P(O)[OC(O)R]₂ [R = C₆H₄2F (1), C₆H₄3F (2), C₆H₄4F (3), C₆H₃2,6F₂ (4), C₆H2,3,5,6F₄ (5)] were prepared by treating silver salts of carboxylic acids AgOC(O)R with CH₃P(O)C?₂ (IR-, ¹H-, ¹⁹?F-and ³¹P{¹H}-NMR-data). The mixed anhydrides 1–5 show unusual thermal stability at room temperature. Stability against hydrolysis decreases with increasing number of fluorine-atoms. The reaction of R′P(O)C?₂ [R′ = CH₃, C₆H₅, (CH₃)₃C] with M^IOC(O)R_F [R_F = CF₃, C₂F₅, C₆F₅; M^I = Ag^I, Na^I T?^I] was investigated.     

Measurement of barriers to aryl rotation in Cp(CO)2FeCHC6H5+ and Cp(CO)2FeCH(p-CH3C6H4)+

The first observation of barriers to rotation about the C_arylC_carbene bonds in aryl-substituted metal carbene complexes is reported. Using variable temperature ¹H NMR, barriers of 9.1 and 10.4 kcal/mol have been determined for Cp(CO)₂FeCHC₆H₅⁺ and Cp(CO)₂FeCH(p-CH₃C₆H₄)⁺, respectively. The data clearly indicate a geometry of the complex in which the aryl ring lies coplanar with FeC_carbeneC_ipso plane.     

Preparation and properties of new ferrocenyl heterobimetallic complexes with counterion dependent NLO responses

New ferrocenyl-based bimetallic cationic compounds of the type of (E)-[CpFe(η⁵-C₅H₄)(CHCH)(C₆H₄)CNRuCp(PPh₃)₂]X (X=PF₆, BF₄) and of (E)-[CpFe(η⁵-C₅H₄)(CHCH)(C₆H₄)CNFeCp(CO)₂]PF₆ have been obtained and characterized. The crystal structure of (E)-[CpFe(η⁵-C₅H₄)(CHCH)(C₆H₄)CNRuCp(PPh₃)₂]BF₄ has been established by means of X-ray diffractometry. The NLO responses of the compounds have been studied by the hyper-Rayleigh scattering technique and the hyperpolarizability is found to be dependent on the nature of the counterion.     

Group IB organometallic chemistry: XXIX. Synthetic and structural aspects of polynuclear arylcopperlithium compounds Ar4Cu2Li2 (“arylcuprates”) and interaggregate exchange phenomena in Ar4Cu4/Ar4Li4/Ar4Cu2Li2 systems

The thermally stable arylmetal-IB-lithium compounds (2-Me₂NCHZC₆H₄)₄M₂Li₂ (M = Cu, Ag or Au; Z = H or Me) and (2-Me₂NC₆H₄)₄M₂Li₂ have been prepared by a $\text{2}\text{1}$ molar reaction of the aryllithium compounds with the corresponding metal-IB halide (Cu or Ag) or metal-lB halide phosphine complex (BrAuPPh₃). These tetranuclear complexes were also made by an interaggregate exchange reaction of the pure arylmetal-IB clusters with the aryllithium compound.The structure of these compounds in solution consists of aryl groups bridging one metal-lB and one lithium atom of a trans M₂Li₂ core. The four built-in ligands coordinate to lithium resulting in two-coordination at M and four-coordination at Li. These conclusions were based on ¹H and ¹³C NMR spectroscopic data (J(AgC(1)), J(LiC(1)) of solutions of these tetranuclear compounds as well as on the ¹⁹⁷Au Mössbauer data of solid (2-Me₂NC₆H₄)₄Au₂Li₂ (IS 5.65 mm/s and QS 12.01 mm/s).The interaggregate exchange between the tetranuclear species is discussed in terms of an associative mechanism involving formation of an octanuclear intermediate in which the aryl groups can migrate via (3c-2e)edge-(2c-2e)corner(3c-2e)edge movements without M₂Ar bond cleavage.Some aspects of the organic reactions in which organocuprates are involved as intermediates are discussed in terms of the novel structural information.     

Vibrational spectra and structural considerations of compounds NaLnTiO4

The Raman and infrared spectra of compounds NaLnTiO₄ (Ln = lanthanide, including yttrium) are reported and discussed. Their most striking feature is a strong band in both spectra at about 900 cm^?1. This band is ascribed to a vibration localized in the TiO bond directed towards the NaO layers. The relevant oxygen anion is very poorly charge compensated, and the TiO bond is, therefore, very strong. Pauling's electrostatic valence rule appears to be of great use in these considerations. These compounds do not show ferroelectricity.     

Reactivity of perfluoroalkenylmagnesium halides : Application to the synthesis of new α-β unsaturated polyfluorinated alcohols and organometallic compounds

The reactivity of perfluoroalkenylmagnesium bromides R_FCFCFMgBr (R_FC₄F₉, C₆F₁₃), obtained from the corresponding l-bromo-perfluoroalkenes, has been investigated.These Grignard reagents react with carbonyl compounds to give, with good yields, a series of new α-β unsaturated polyfluorinated alcohols R_FCFCFC(OH)RR′ (1). The synthesis and spectrographic characteristics of these compounds are reported and discussed.Perfluoroalkenyl mercuric and tin derivatives are obtained from the reaction of the perfluorinated Grignard reagents with mercuric salts and organotin halides respectively :

Spectroscopic identification and some chemical properties of these new perfluorinated organometallic compounds are given.The good reactivity of these unsaturated derivatives towards protic acids and electrophiles, leading to the cleavage of the perfluoroalkenyl group, is used to study the possibilities of transmetallation reactions.Somes examples of these reactions are reported.     

Metal–azo and metal–imine compounds II. : II. Insertion of Ir1 into aromatic and olefinic CH bonds

The reaction of the aromatic azo or imine compounds PhX=NR (X=N or CH; R = alkyl or aryl) and 2-(methylazo)propene, H₂CC(CH₃)N&.zdbnd;NCH₃, with trans-IrCl(N₂)(PPh₃)₂ yields the (ortho) metallated complexes IrHCl(G₆H₄X=NR)(PPh₃)₂ and IrHClCHC(CH₃)-NNCH₃](PPh₃)₂ respectively.The v(N=N) vibration in IrHCl(C₆HZ₄N=NPh)(PPh₃)₂ appears to be drastically lowered with respect to the free ligand vibration. Furthermore, Resonance Raman experiments show that this vibration is strongly coupled to both of the electronic transitions of this compound at longer wavelengths, which therefore must be closely connected with the azo group.¹H and ¹³C NMR spectroscopic data and crystallographic studies of IrHCI(C₆H₄N=NPh)(PPh₃)₂ give strong evidence about the nature of the mechanism of these (ortho) metallation reactions.     

13C and 29Si chemical shifts and coupling constants involving tris[(trimethylsilyl)methyl] silicon compounds

Silicon-29(δ²⁹Si) NMR chemical shifts are reported for the first time of tris[(trimethylsilyl)methyl] silicon compounds (disilylated derivatives) (Me₃Si^A)₃ C_αL, where L = Si^BR₁R₂R₃ and where R varies widely in electronegativity. ²⁹Si chemical shifts exhibit good correlation with the electronegativities of the groups bonded to the silicon atom. The ¹³C NMR spectra of these compounds have been recorded and assigned. δ¹³C_α is shown to depend on the type of substitutent on Si^B. The variation of ²⁹SiH coupling constants with electronegativity of R is studied.     

A 19F NMR study of the transmission of electronic effects in triarylantimony and triarylbismuth compounds. A comparison with the nitrogen- and carbon-containing analogues

A ¹⁹F NMR study of the transmission of electronic effects has been made for the systems Ar₂EC₆H₄F-4 (E = Sb, Bi, CH, N). The fluorine chemical shifts obtained are correlated with the polar constants (Σσ^o and Σσ) of the substituents, suggesting that electronic effects are transmitted through the SbC_ar, BiC_ar and CC_ar bonds predominantly by an inductive mechanism, whereas the transmission through the NC_ar bonds is contributed to significantly by classical resonance effects due to competitive conjugation of the lone pair with the aromatic rings, and the substituents therein. A dual parameter correlation of the fluorine chemical shifts with the inductive (σ_I) and resonance (σ^o_R and σ_R) parameters of the substituents in the aromatic rings has led to similar conclusions. The inductive transmission through the bridging Sb and Bi atoms has been assigned to the absence of conjugation of lone pair and vacant d-orbitals of the metals with π-electron systems of the aromatic rings. On the basis of the values of the ? coefficients for the correlation equations obtained it has been established that the transmitting ability of the BiC_ar bonds is close to that of the C_alC_ar bonds and considerably lower than the transmitting ability of the NC_ar bonds.     

Chemistry of strained polycyclic compounds—V : The stereospecific cationic cage expansion reaction of 4-homocubane carbinols to 1,3-bishomocubane bridgehead alcohols

The cationic rearrangement of four homocubane bridgehead carbinols viz dimethyl 4-(1-bromopentacyclo[4.3.0.0^2,5.0^3,8.0^4,7]nonyl-9-one ethylene ketal) carbinol 2, diphenyl 4-(1-bromopentacyclo[4.3.0.0^2,5.0^3,8.0^4,7]nonyl-9-one ethylene ketal) carbinol 3, 4-(1-bromopentacyclo[4.3.0.0^2,5.0^3,8.0^4,7] nonyl-9-one ethylene ketal) carbinol 4 and 4-(1-bromopentacyclo[4.3.0.0^2,5.0^3,8.0^4,7]nonyl) carbinol 16, has been studied undervarious conditions.Exclusive migration of the C₄C₇ (or the equivalent C₃C₄ bond) in the homocubane skeleton was observed leading to 1,3-bishomocubane bridgehead alcohols. Relief of cage constraint governs the selective course of these cage expansions.     

Aspects of the Chemistry of Diarylditellurides and Related Compounds containing Telurium to Tin Bonds

The examination mixtures of two ditellurides by mass and ¹H nmr spectroscopies provides the first evidence for the existence of unsymmetrical diarylditellurides, RTeTeR′. Possible mechanisms for the redistribution reaction are discussed and it is noted that no positive support for a radical mechanism is obtained. Appearance potential measurements on the ion (aryl)Te⁺ derived from a number of organotellurium compounds suggest that tellurium extrusion may be a low energy pathway for the decomposition of diarylditellurides. A new series of compounds, Ph₃SnTe(aryl) is reported and they are examined by ¹¹⁹Sn and ¹²⁵Te Mösabauer spectroscopies. Attempts are made to interpret the Mösabauer data in terms of orbital populations, and it is demonstrated that only an sp bonding model gives a self-consistent interpretation of the combined tin and tellurium Mösabauer data.     

Organolead chemistry : III. 207Pb chemical shifts in some organolead compounds

²⁰⁷Pb chemical shifts are reported for the compounds (CH₃)_4?nPb X_n, where n = 1 · 4, X = 4-FC₆H₄; n = 1, 2, 4, X = CH₃ CC; n = 1, 4, X = CH₂CH; n = 1, X = Cl, CH₃O, CH₃CO₂. A correlation between δ(²⁰⁷Pb) and δ(¹⁹F) for the 4-fluorophenyl derivatives is discussed, and solvent effects on δ(²⁰⁷Pb) for the propynyl derivatives are interpreted in terms of complex formation.