New Synthetic Routes to β-Olefinic Triphenylphosphonium Salts via (Diolefin)tricarbonyliron Complexes

The regio- and stereospecific preparation of β-olefinic triphenylphosphonium salts, starting from (diolefin)tricarbonyliron compounds is described. The latter are converted by various routes into either [(allyl)Fe(CO)₄]⁺ - or [(dienyl)Fe(CO)₃]⁺ - derivatives. The allylic cations, when reacted with P (C₆H₅)₃, yield uncomplexed (2-en-l-yl)triphenylphosphonium salts in good yields, while treatment of the dienyl cations with P(C₆H₅)₃ leads to the quantitative formation of (2,4-diene-l-yl)triphenylphosphonium ions still coordinated to the Fe (CO)₃-moiety. A method of oxidative decomplexation is described, by which the free phosphonium salts can be obtained. All new compounds were characterized by ¹³C-NMR spectra and also, where necessary, by ¹H-NMR decoupling experiments to confirm the stereochemical assignments. Many of the new phosphonium salts, potentially useful as Wittig reagents for natural product syntheses, are difficult to obtain by conventional unequivocal routes.     

Darstellung und Eigenschaften neuer kationischer Dienyl-isonitril-dicarbonyl-Komplexe des Eisens und Rutheniums

Preparation and Properties of New Cationic Dienyl-isonitrile-dicarbonyl Complexes of Iron and Ruthenium The hydride abstraction from the η⁴-diene isonitrile metal dicarbonyls M(η⁴-dien)(CNR)(CO)₂ (M = Fe, Ru; dien = C₆H₈ cyclohexadiene-1.3; C₇H₁₀ cycloheptadiene-1.3; R = Me, Et) with [Ph₃C]BF₄ lead to the η⁵-dienyl isonitrile dicarbonyl metal cations [M(η⁵-dienyl)(CNR)(CO)₂]⁺ [dienyl = cyclohexa-2.4-dien-1-yl (C₆H₇), cyclohepta-2.4-dien-1-yl (C₇H₉)]. [Fe(η⁵? C₈H₉)(CNMe)(CO)₂]⁺ (C₈H₉ = bicyclo[5.1.0]octa-3.5-dien-2-yl) is formed by protonation of Fe(η⁴? C₈H₈)(CNMe)(CO)₂ (C₈H₈ = COT) under valency isomerization. The two cations [Fe(η⁵? C₇H₉)(CNMe)(CO)₂]⁺ and [Fe(η⁵? C₈H₉)(CNMe)(CO)₂]⁺ can be deprotonated with NEt₃ to the neutral cycloheptatriene respectively COT complexes Fe(η⁴? C₇H₈)(CNMe)(CO)₂ and Fe(η⁴? C₈H₈)(CNMe)(CO)₂. The temperature dependent ¹³C-NMR spectra of [Fe(η⁵? C₇H₉)(CNMe)(CO)₂]⁺ and [Ru(η⁵? C₆H₇)(CNMe)(CO)₂]⁺ show the fluctional behaviour of these cations in solution. At low temperatures one CO group occupies the apical position of a square pyramid whereas the isonitrile ligand, the other CO group and the dienyl part are in the basal positions. The ΔG values of the CP exchange points out a higher activation energy as in the corresponding η⁴-diene metal complexes.     

Chelating and Tellurolate Ligand‐Transfer Studies of the Complex fac‐[Fe(CO)3(TePh)3]−: Crystal Structures of Heterodinuclear (CO)3Mn(μ‐TePh)3Fe(CO)3 and CpNi(TePh)(PPh3)

Complex fac‐[Fe(CO)₃(TePh)₃]^? was employed as a “metallo chelating” ligand to synthesize the neutral (CO)₃Mn(μ‐TePh)₃Fe(CO)₃ obtained in a one‐step synthesis by treating fac‐[Fe(CO)₃(TePh)₃]^? with fac‐[Mn‐(CO)₃(CH₃CN)₃]⁺. It seems reasonable to conclude that the d⁶ Fe(II) [(CO)₃Fe(TePh)₃]^? fragment is isolobal with the d⁶ Mn(I) [(CO)₃Mn(TePh)₃]^2? fragment in complex (CO)₃Mn(μ‐TePh)₃Fe(CO)₃. Addition of fac‐[Fe(CO)₃(TePh)₃]^? to the CpNi(I)(PPh₃) in THF resulted in formation of the neutral CpNi(TePh)(PPh₃) also obtained from reaction of CpNi(I)(PPh₃) and [Na][TePh] in MeOH. This investigation shows that fac‐[Fe(CO)₃(TePh)₃]^? serves as a tridentate metallo ligand and tellurolate ligand‐transfer reagent. The study also indicated that the fac‐[Fe(CO)₃(SePh)₃]^? may serve as a better tridentate metallo ligand and chalcogenolate ligand‐transfer reagent than fac‐[Fe(CO)₃(TePh)₃]^? in the syntheses of heterometallic chalcogenolate complexes.     

Phosphite addition to organometallic cations to give phosphonium adducts

Addition of tri-n-butylphosphite to [(C₆H₇)Fe(CO)₃]BF₄, [(C₆H₆OMe)-Fe(CO)₃]BF₄, and [(C₇H₇)Cr(CO)₃]BF₄ has yielded novel phosphonium salts; which are remarkably stable.     

Kinetics of nucleophilic attack on coordinated organic moieties : VI. Mechanism of addition of tri-n-butylphosphine to [(C7H7)M(CO)3]BF4 (M = Cr, Mo, W) and related cations

Phosphonium adduct formation via attack of tri-n-butylphosphine on the cations [(C₇H₇)M(CO)₃]⁺ (M = Cr, Mo, W) obeys the rate law, Rate = k [complex] [PBu₃]. The very similar rate constants for the Cr, Mo and W complexes confirm the similar electrophilicities of the tropylium rings in these cations, and also support the view that there is direct addition to the rings. The related complexes [(C₆H₇)Fe(CO)₃]BF₄ and [(C₆H₆)Mn(CO)₃]BF₄ also form adducts with PBu₃, and the quantitative reactivity order [(C₆H₇)Fe(CO)₃]⁺ > [(C₇H₇)Cr(CO)₃]⁺ » [(C₆H₆)Mn(CO)₃]⁺ (160:60:1) has been established.     

Unprecedented and Effective Synthesis of Thiazolines from Perfluoro-3-isothiocyanato-2-methyl-2-pentene and Certain P-Nucleofuges

The reactions of perfluoro-3-isothiocyanato-2-methyl-2-pentene with PPh₃ and P(NEt₂)₃ in the presence of NaBF₄, KI, and NaBPh4 form phosphonium salts with the heterocyclic substituent (4E)-5,5-bis(trifluoromethyl)-4-(tetrafluoroethylidene)-4,5-dihydro-1,3-thiazol-2-yl, instead of involving desulfurization and formation of P-F-containing products. The reaction with tris(pentafluorophenyl)phosphine fails. The reactions with P(OEt)₃ in the presence of ClSiMe₃ or (CH₃O)₂POSiMe₃ yield diethyl or dimethyl [(4E)-5,5-bis(trifluoromethyl)-4-(tetrafluoroethylidene)-4,5-dihydro-1,3-thiazol-2-yl]phosphonates and no intramolecular alkylation products. The ¹H, ¹³C, ¹⁹F, and ³¹P spectra are presented, and the reaction pathways are discussed. Potential mechanisms of the biological and catalytic activity of the reaction products are considered.     

Anomalous behaviour of an allyl alcohol in reaction with iron pentacarbonyl

[(6,7,8,9-η)-Bicyclo[3.2.2]nona-2,6,8-trien-4-ol]tricabonyliron (6) rearranges in the presence of Fe(CO)₅ to [(2,3,6,7-η)-bicyclo[3.2.2]nona-2,6,8-trien-4-one] tricarbonyliron (7); rather than [(6,7,8,9-η)-bicyclo-[3.2.2]nona-6,8-dien-2-one] tricarbonyliron (9), the product expected on the basis of known organoiron chemistry and previously proposed mechanisms. The starting material 6 is stable in the absence of Fe(CO)₅, which leads to the conclusion that some iron-containing species derived from fe(CO)₅ is responsible for bringing about rearrangement. Since the usual mechanism for iron carbonyl-induced rearrangement in olefins cannot be operating here, a mechanism involving an ion pair with [HFe(CO)₄]^- is suggested.     

Reaction Behavior of Decacarbonyldimetalates(2‐) (M = Cr and Mo) towards the Nitrosyl Carbonyls of Iron and Cobalt

The reaction of the nitrosyl carbonyl complexes [Fe(NO)₂(CO)₂] and [Co(NO)(CO)₃] with the decacarbonyldimetalates [M₂(CO)₁₀]^2– (M = Cr and Mo) in THF as the solvent at room temperature was investigated. Thereby a substitution of one nitrosyl ligand towards carbon monoxide was observed in each case. Both reactions afforded the known metalate complexes [Fe(NO)(CO)₃]^– and [Co(CO)₄]^–, respectively. These species were isolated as their corresponding PPN salts [PPN⁺ = bis(triphenylphosphane)iminium cation] in nearly quantitative yields. The products were unambiguously identified by their IR spectroscopic and elemental analytic data as well as by their characteristic colors and melting points.     

Heteronukleare Komplexverbindungen mit Metall—Metall-Bindungen. VIII. Neue heterodinukleare Komplexe mit Bindungen zwischen Kupfer(I) und Mangan(–I), Eisen(–I) oder Cobalt(–I)

Heteronuclear Coordination Compounds with Metal—Metal Bonds. VIII. New Heterodinuclear Complexes with Bonds between Copper(I) and Manganese(?I), Iron(?I), or Cobalt(?I) [(en)Cu? Mn(CO)₅] ( 1a ), [(dien)Cu? Mn(CO)₅] ( 1b ), [(en)Cu? Fe(CO)₃(NO)] ( 2a ), [(dien)Cu? Fe(CO)₃(NO)] ( 2b ), [(en)Cu? Co(CO)₄] ( 3a ), and [(dien)Cu? Co(CO)₄] ( 3b ) are new heterobinuclear metal—metal bonded complexes. The geometry of the [Mn(CO)₅]^?, [Fe(CO)₃(NO)]^?, and [Co(CO)₄]^? ions is distorted only to a less extend in accord with a heteropolar bond to copper.     

Protonation of γ-Butyrolactone and γ-Butyrolactam

Abstract : γ-Butyrolactone and γ-butyrolactam were reacted in the superacidic systems XF/MF₅ (X=H, D; M=As, Sb). Salts of the monoprotonated species of γ-butyrolactone were obtained in terms of [(CH₂)₃OCOH]⁺[AsF₆]⁻, [(CH₂)₃OCOH]⁺[SbF₆]⁻ and [(CH₂)₃OCOD]⁺[AsF₆]⁻ and the analogous lactam salts in terms of [(CH₂)₃NHCOH]⁺[AsF₆]⁻, [(CH₂)₃NHCOH]⁺[SbF₆]⁻ and [(CH₂)₃NDCOD]⁺[AsF₆]⁻. The salts were characterized by low temperature Raman and infrared spectroscopy and for both protonated hexafluoridoarsenates, [(CH₂)₃OCOH]⁺[AsF₆]⁻ and [(CH₂)₃NHCOH]⁺[AsF₆]⁻, single-crystal X-ray structure analyses were conducted. In addition to the experimental results, quantum chemical calculations were performed on the B3LYP/aug-cc-pVTZ level of theory. As in both crystal structures C⋅⋅⋅F contacts were observed, the nature of these contacts is discussed with Mapped Electrostatic Potential as a rate of strength.     

Synthesis,spectroscopic characterization and antibacterial studies of some derivatives of chlorodimethylsulphoxide/tetramethylenesulphoxide ruthenium(II) and ruthenium(III) with 4-aminoantipyrine

We report the synthesis of five complexes of three different formulations viz. [cis-RuCl₂(4-antp)₂], [trans-RuCl₂(4-antp)₂] and [X]⁺[trans-RuCl₄(4-antp)₂]^? (X⁺ = [(DMSO)₂H]⁺, Na⁺, or [(TMSO)H]⁺ and 4-antp = 4-aminoantipyrine) from different routes. These complexes were characterized on the basis of elemental analyses, molar conductance measurements, magnetic susceptibility, electronic spectra, FTIR, ¹H-NMR and ¹³C{¹H}-NMR spectroscopy. Complexes were screened for antibacterial activity and found to be potent against gram negative bacteria Escherichia coli.     

Addition des O'Donnell Reagenzes [Ph2C=NCHCO2Me]– an π-koordinierte,ungesättigte Kohlenwasserstoffe in [(C6H7)Fe(CO)3]+, [(C7H9)Fe(CO)3]+, [(C7H7)M(CO)3]+ (M = Cr,Mo) und [(C2H4)Re(CO)5]+. α-Aminosäuren mit metallorganischen Seitenketten

Metal Complexes of Biologically Important Ligands. CXVII [1] Addition of the O'Donnell Reagent [Ph₂C=NCHCO₂Me]^– to Coordinated, Unsaturated Hydrocarbons of [(C₆H₇)Fe(CO)₃]⁺, [C₇H₉Fe(CO)₃]⁺, [(C₇H₇)M(CO)₃]⁺ (M = Cr, Mo), and [(C₂H₄)Re(CO)₅]⁺. α-Amino Acids with Organometallic Side Chains The addition of [Ph₂C=NCHCO₂Me]^– to [(C₆H₇)Fe(CO)₃]⁺, [(C₇H₉)Fe(CO)₃]⁺, [(C₇H₇)M(CO)₃]⁺ (M = Cr, Mo) and [(C₂H₄)Re(CO)₅]⁺ gives derivatives of α-amino acids with organometallic side chains. The structure of [(η⁴-C₆H₇)CH(N=CPh₂)CO₂Me]Fe(CO)₃ was determined by X-ray diffraction. From the adduct of [Ph₂C=NCHCO₂Me]^– and [(C₇H₇)Mo(CO)₃]⁺ the Schiff base of a new unnatural α-amino acid, Ph₂C=NCH(C₇H₇)CO₂Me, was obtained.     

A Systematic Investigation of Coinage Metal Carbonyl Complexes Stabilized by Fluorinated Alkoxy Aluminates

The reaction of Cu^I, Ag^I, and Au^I salts with carbon monoxide in the presence of weakly coordinating anions led to known and structurally unknown non‐classical coinage metal carbonyl complexes [M(CO)_n][A] (A=fluorinated alkoxy aluminates). The coinage metal carbonyl complexes [Cu(CO)_n(CH₂Cl₂)_m]⁺[A]^? (n=1, 3; m=4?n), [Au₂(CO)₂Cl]⁺[A]^?, [(OC)_nM(A)] (M=Cu: n=2; Ag: n=1, 2) as well as [(OC)₃Cu???ClAl(OR^F)₃] and [(OC)Au???ClAl(OR^F)₃] were analyzed with X‐ray diffraction and partially IR and Raman spectroscopy. In addition to these structures, crystallographic and spectroscopic evidence for the existence of the tetracarbonyl complex [Cu(CO)₄]⁺[Al(OR^F)₄]^? (R^F=C(CF₃)₃) is presented; its formation was analyzed with the help of theoretical investigations and Born–Fajans–Haber cycles. We discuss the limits of structure determinations by routine X‐ray diffraction methods with respect to the C? O bond lengths and apply the experimental CO stretching frequencies for the prediction of bond lengths within the carbonyl ligand based on a correlation with calculated data. Moreover, we provide a simple explanation for the reported, partly confusing and scattered CO stretching frequencies of [Cu^I(CO)_n] units.     

Acylation Reactions of Dibenzo-7-phosphanorbornadiene: DFT Mechanistic Insights

Extensive DFT calculations provide deep mechanistic insights into the acylation reactions of tert-butyl dibenzo-7-phosphanobornadiene with PhCOX (X=Cl, Br, I, OTf) in CH₂Cl₂ solution. Such reactions are initialized by the nucleophilic P⋅⋅⋅C attack to the carbonyl group to form the acylphosphonium intermediate A⁺ together with X⁻ anion, followed either by nucleophilic X⁻⋅⋅⋅P attack (X=Cl, Br, and I) toward A⁺ to eliminate anthracene or by slow rearrangement or decomposition of A⁺ (X=OTf). In contrast to the first case (X=Cl) that is rate-limited by the initial P⋅⋅⋅C attack, other reactions are rate-limited by the second X⁻⋅⋅⋅P attack for X=Br and I and even thermodynamically prevented for X=OTf, leading to isolable phosphonium salts. The rearrangement of phosphonium A⁺ is initiated by a P-C bond cleavage, followed either by sequential proton-shifts to form anthracenyl acylphosphonium or by deprotonation with additional base Et₃N to form neutral anthracenyl acylphosphine. Our DFT results strongly support the separated acylphosphonium A⁺ as the key reaction intermediate that may be useful for the transfer of acylphosphenium in general.     

Bestimmung von Gleichgewichtskonstanten für Ligandenaustauschreaktionen von [TcNX4]− (X = Cl,Br) mit Hilfe der EPR

Polynuclear Complexes with Fe? As, Fe? Sb, and Fe? Bi Frameworks The anionic iron clusters Fe₃(CO)₁₁^2? and Fe₄(CO)₁₃^2? were reacted with compounds EX₃ and with organic derivatives REX₂ and R₂EX of the elements arsenic, antimony, and bismuth. Commonly redox and cluster degradation reactions were observed. The new complexes [(CO)₄Fe? AsMe₂? Fe(CO)₄]^?, [HFe₃(CO)₉(mu;₃-SbBu^t)]^?, [Fe₃(CO)₁₀ (mu;₃-Sb)]^?, and [Fe₃(CO)₁₀(mu;₃-Bi)]^? were formed and isolated as their PPN salts. The Fe? As? Fe complex was identified by a structure determination, the other complexes were identified by their spectra.     

Binuclear organometallic compounds VIII. Oxidative addition of Si-H or Si-Cl compounds to low valent Fe, Co, or Ni complexes stabilised by mono- or bi-dentate phosphines

The reactions of [(Ph₃P)₄Ni], [(Ph₃P)₃CoN₂], [(dp)₂Ni], [(dp)₂CoH], [(dp)₂Fe(C₂H₄)] or [(dp)₂FeH₂] (dp = Ph₂PCH₂CH₂Ph₂P) with Ph_nSiCl_4-n (n = 1, 2, or 3), Ph_nSiH_4-n, X₃SiH (X = Cl or Et), or R₂ClSiH (R = Ph or Me) have been investigated. Solid complexes were isolated which, for the most part, were insoluble in non-polar solvents. Assignments of structures are therefore incomplete, and are based on microanalysis, IR spectra, analogies with established reactions, and (in some cases) chemical degradation. Evidence is presented for the following: (i) for Ni^II, products from [(Ph₃P)₄Ni] and HSiXX′X″ (XX′X″ = Ph₃, Ph₂H or PhH₂), the cyclic [(Ph₃P)₂NiSiCl₂]₂, and the five-coordinate [(dp)₂-NiX]⁺[SiCl₃]^- (X = H or Cl₃Si); (ii) for Co^III, the six-coordinate cis-octahedral [(dp)₂CoH₂]⁺ [SiXX′X″]^- (XX′X″ = Cl₃, Cl₂Me, ClMe₂, or ClPh₂); and for Fe^II, the four-coordinate [(dp)FeH(SiCl₃)] and the six-coordinate [(dp)₂Fe(X)SiCl₃] (X = H, Cl, or Cl₃Si).     

Liquid-liquid extraction of metal ions with tris (2,6-dimethoxyphenyl) phosphine and its quaternary phosphonium salts

The extraction of various metal ions from hydrochloric acid solutions with tris(2,6-dimethoxyphenyl)phosphine, [2,6-(MeO)₂C₆H₃]₃P, abbreviated to (2,6-MeOPh)₃P, and its tertiary and quaternary phosphonium salts were studied. A series of phosphonium salts, [(2,6-MeOPh)₃PH]⁺ClO^?₄, [(2,6-MeOPh)₃PR]⁺Br^? and {[(2,6-MeOPh)₃P]₂R′}²⁺ (Br^?)₂, where R = C₁₂H₂₅, C₁₈H₃₇ or C₆H₅CH₂ and R′ = p-CH₂C₆H₄CH₂, (CH₂)₃ and (CH₂)₁₀, were synthesized and applied to an anion exchanger for chloro complex anions of various metal ions. (2,6-MeOPh)₃P and [(2,6-MeOPh)₃PR]⁺Br^? were found to be effective for the extraction of metal ions such as iron(III), gold(III) and gallium(III), forming tetrachloro complex anions of the M^IIICl^?₄ type. The extractabilities of the doubly charged cationic quaternary phosphonium salts [{(2,6-MeOPh)₃P}₂R′]²⁺ (Br^?₂, were found to be superior to those of the singly charged cationic phosphonium salts for metal ions such as cadmium(II), platinum(II) and palladium(II), forming a tetrachloro complex doubly charged aion of the M^IICl^2?₄ type. Most of the metal ions are extracted through ion-pair formation between their chloro complex anions and the phosphonium cations.     

Synthesis of cationic indenyliron complexes: [η5-C9H7Fe(CO)2L]+ (L = phosphine,phosphite, CO)

Synthetic routes to the cationic complexes [η⁵-C₉H₇Fe(CO)[₂L]⁺, (L = CO, phosphine, phosphite, nitrile, pyridine) have been investigated. The most versatile method is oxidation of the dimer [η⁵-C₉h₇Fe(CO)₂]₂ with ferricinium ion. in the presence of the appropriate ligand. [η⁵-C₉H₇Fe(CO)₃]⁺ is best prepared by oxidation of the dimer with Ph₃CBF₄. This tricarbonyl cation readily loses one CO group on reactiom with phosphines and P(OCH₃). The acentonitrile ligand [η⁵-C₉H₇Fe(CO)₂CH₃CN]⁺ can also be replaced bny phosphines. Finally, reactions of η⁵-C₉H₇Fe(CO)₂X, (X = Br, I) with phosphines also yield cationic products isolatedas PF₆⁻ salts.     

Preparation and synthetic utility of fluorinated phosphonium salts,bisphosphonium salts and phosphoranium salts

The synthesis and mechanism of formation of phosphonium salts of the type [R₃$\text{P}\text{+}$CFXY]Z^? (where X = F, Cl, Br; Y = Br, Cl; Z = Br, Cl), $\text{bis}$-phosphonium salts of the type [R₃$\text{P}\text{+}$CF₂$\text{P}\text{+}$R₃]2Br^?, and phosphoranium salts of the type [R₃$\text{P}\text{+}$$\text{C}\text{?}$F$\text{P}\text{+}$R₃]X^? (X = Br, Cl) will be presented. The applicability of these substrates in the generation of useful nucleophilic or electrophilic synthetic intermediates will be discussed.     

Room-Temperature Synthesis of the Bi5[GaCl4]3 Salt From Three Different Classes of Ionic Liquids

Following the development in the synthesis of subvalent cluster compounds, we report on the use of three different classes of room-temperature ionic liquids for the synthesis of the pentabismuth-tris(tetragallate) salt, Bi₅[GaCl₄]₃, characterized by X-ray diffraction. The Bi₅[GaCl₄]₃ salt was prepared by reduction of BiCl₃ using gallium metal in ionic liquid reaction media containing a strong Lewis acid, GaCl₃. The ionic liquids; trihexyltetradecyl phosphonium chloride [Th-Td-P⁺]Cl^?, 1-dodecyl-3-methylimidazolium chloride [Dod-Me-Im⁺]Cl^? and N-butyl-N-methylpyrrolidinium chloride [Bu-Me-Pyrr⁺]Cl^? from three of the main classes of ionic liquids were used in synthesis. Reactions using ionic liquids composed of the trihexyltetradecyl phosphonium cation [Th-Td-P⁺] and the anions; tetrafluoroborate [BF₄ ^?], bis(trifluoro-methyl sulfonyl) imide [(Tf)₂N^?] and hexafluorophosphate [PF₆ ^?] were also investigated.