Metallkomplexe mit biologisch wichtigen Liganden. CLVII [1] Halbsandwich‐Komplexe mit Isocyanoacetylaminosäureestern und Isocyanoacetyldi‐ und tripeptidestern („Isocyano‐Peptide”︁)

Metal Complexes of Biologically Important Ligands, CLVII [1] Halfsandwich Complexes of Isocyanoacetylamino acid esters and of Isocyanoacetyldi‐ and tripeptide esters (?Isocyanopeptides”?) N‐Isocyanoacetyl‐amino acid esters CNCH₂C(O) NHCH(R)CO₂CH₃ (R = CH₃, CH(CH₃)₂, CH₂CH(CH₃)₂, CH₂C₆H₅) and N‐isocyanoacetyl‐di‐ and tripeptide esters CNCH₂C(O)NHCH(R¹)C(O)NHCH(R²)CO₂C₂H₅ and CNCH₂C(O)NHCH(R¹)C(O)NHCH (R²)C(O)NHCH(R³)CO₂CH₃ (R¹ = R² = R³ = CH₂C₆H₅, R² = H, CH₂C₆H₅) are available by condensation of potassium isocyanoacetate with amino acid esters or peptide esters. These isocyanides form with chloro‐bridged complexes [(arene)M(Cl)(μ‐Cl)]₂ (arene = Cp*, p‐cymene, M = Ir, Rh, Ru) in the presence of Ag[BF₄] or Ag[CF₃SO₃] the cationic halfsandwich complexes [(arene)M(isocyanide)₃]⁺X^? (X = BF₄, CF₃SO₃).     

Mono and Bisphosphonates from Perfluoro Olefins and Polyfunctional Fluoro Ketones. Syntheses,Molecular Structure and Derivatives

Perfluoroalkenyl phosphonates were formed along with Me₃SiF using CF₃CF=CF₂, CF₃CH=CF₂, F₅SCF=CF₂ or F₅SCH=CF₂ and silylated phosphites, (R¹O)₂POSiMe₃ (R¹=Et, SiMe₃). This straightforward method could be extended to perfluorobutadienes CF₂=C(R^F)C(R^F)=CF₂ (R^F F=F, CF₃). The formation of CF₃C(=O)P(=O)(OSiMe₃)₂ and further reactions to yield bisphosphonates will be described. Acetylphosphonates, R²C(=O)P(=O)(OSiMe₃)₂ (R²=CH₃, CF₃) reacted with the ketimine, CH₃C(=NiPr)Ph to give α-hydroxy-γ-imino phosphonates. Trifluoroacetylphenol and 2,6-bis(trifluoracetyl)-4-methyl-phenol have been proven to be versatile precursors for α-and γ-hydroxy phosphonates. Intermediates in these reactions were found to be cyclic λ⁵σ⁵P species.     

Novel ammonium hexafluoroarsenate salts from reaction of (CF3)2NH,CF3N(OCF3)H,CF3N[OCF(CF3)2]H,CF3NHF and SF5NHF with the strong acid HF/ASF5.

Reactions of the fluorinated amines (CF₃)₂NH, CF₃N(OCF₃)H, CF₃N[OCF(CF₃)₂]H, CF₃NHF and SF₅NHF with the strong acid HF/AsF₅ form the corresponding ammonium salts R_f¹R_f²NH₂⁺AsF₆^? and R_fNFH₂⁺ AsF₆^? in high yield. [R_f¹=CF₃, R_f²=CF₃, CF₃O, (CF₃)₂CFO; R_f=CF₃, SF₅] The colorless crystalline solids are stable for prolonged periods at 22°C in sealed FEP containers. They have dissociation pressures at 22°C ranging from ～5 torr (R_fNFH₂⁺ AsF₆^?) to ～50 torr [CF₃N(OCF₃)H₂⁺AsF₆^?]. ¹⁹F NMR and Raman spectroscopy were used to identify the compounds.     

First examples of stable polyfluorinated bis- and tris-(alkoxy)methyl cations

Stable polyfluorinated bis- and tris-(alkoxy)methyl cations were prepared by the reaction of the corresponding difluoroformals (R_fO)₂CF₂ (R_f = -CH₂CF₃, -CH(CF₃)₂, -CH₂CF₂Cl) with an excess of SbF₅. Although the cation (CF₃CH₂O)₂CF⁺ (1a) is stable at ambient temperature, the chlorinated analog (ClCF₂CH₂O)₂CF⁺ (3a) can be generated only at low temperature in SO₂ClF solvent and rapidly decomposes at ambient temperature. Although the salt [(CF₃)₂CHO]₂CF⁺Sb_nF_5n+1⁻ (2a) is slightly more stable than the salt of cation 3a, at ambient temperature it undergoes rapid disproportionation with formation of equal amounts of [(CF₃)₂CHO]₃C⁺Sb_nF_5n+1⁻ (2b) and CF₃OCH(CF₃)₂ (2c). Stable solid salt 2b (n = 2) was isolated and fully characterized by ¹H, ¹⁹F and ¹³C NMR spectroscopy and its structure was confirmed by single crystal X-ray diffraction.     

Syntheses,Structures, Reactivities,and Basicities of Quinolinyl and Isoquinolinyl Complexes of an Electron Rich Chiral Rhenium Fragment and Their Electrophilic Addition Products

Reactions of Li⁺ [(η⁵-C₅H₅)Re(NO)(PPh₃)]⁻ with 2- and 4-chloroquinoline or 1-chloroisoquinoline give the corresponding σ quinolinyl and isoquinolinyl complexes 3 , 6 , and 8 . With 3 and 8 there is further protonation to yield HCl adducts, but additions of KH give the free bases. Treatment of 3 with HBF₄⋅OEt₂ or H(OEt₂)₂⁺ BAr_f⁻ gives the quinolinium salts [(η⁵-C₅H₅)Re(NO)(PPh₃)(C(NH)C(CH)₄C (CH)(CH))]⁺ X⁻ ( 3-H ⁺ X⁻; X⁻=BF₄⁻/BAr_f⁻, 94–98 %). Addition of CF₃SO₃CH₃ to 3 , 6 , or 8 affords the corresponding N-methyl quinolinium salts. In the case of [(η⁵-C₅H₅)Re(NO)(PPh₃)(C(NCH₃)C(CH)₄C (CH)(CH))]⁺ CF₃SO₃⁻ ( 3-CH₃ ⁺ CF₃SO₃⁻), addition of CH₃Li gives the dihydroquinolinium complex (S_ReR_C,R_ReS_C)-[(η⁵-C₅H₅)Re(NO)(PPh₃)(C(NCH₃)C(CH)₄C (CHCH₃)(CH₂))]⁺ CF₃SO₃⁻ ((S_ReR_C,R_ReS_C)- 5 ⁺ CF₃SO₃⁻, 76 %) in diastereomerically pure form. Crystal structures of 3-H ⁺ BAr_f⁻, 3-CH₃ ⁺ CF₃SO₃⁻, (S_ReR_C, R_ReS_C)- 5 ⁺ Cl⁻, and 6-CH₃ ⁺ CF₃SO₃⁻ show that the quinolinium ligands adopt Re⋅⋅⋅ C conformations that maximize overlap of their acceptor orbitals with the rhenium fragment HOMO, minimize steric interactions with the bulky PPh₃ ligand, and promote various π interactions. NMR experiments establish the Brønsted basicity order 3 > 8 > 6 , with K_a(BH⁺) values >10 orders of magnitude greater than the parent heterocycles, although they remain less active nucleophilic catalysts in the reactions tested. DFT calculations provide additional insights regarding Re⋅⋅⋅ C bonding and conformations, basicities, and the stereochemistry of CH₃Li addition.     

Triphenyltelluronium β-diketonates; Synthesis and spectra

Triphenyltelluronium /gb-diketonates, RC(O)CHC(O)R¹ (where R = CH₃, Ph or CF₃ and R¹ = CH₃, Ph, CF₃ or 2-thienyl) have been prepared. Spectral data(IR, ¹H and ¹³C NMR, mass spectroscopy) are presented and discussed in conjunction with molecular weight and conductivity data. It is concluded that weak coordination of the β-diketonate to the tellurium atom is a common structural feature of the compounds.     

On the reactions of dimethylsulfoxide with acyl fluorides - pummerer rearrangements and formation of monofluoromethyl esters

In stoichiometry-dependent reactions, dimethylsulfoxide (DMSO) reacts with acyl fluorides, R_fC(O)F (R_f = F, CF₃), to yield CH₃SCH₂F and R_fC(O)OCH₂F, while CH₃SCH₂Cl and FC(O)OCH₂Cl are obtained with COClF. Oxalyl difluoride, C₂O₂F₂, reacts with DMSO to give CH₃SCH₂F and FCH₂OCH₂F.     

Synthesen und Eigenschaften von Tetrakis(perfluoralkyl)tellur Te(Rf)4 (Rf = CF3, C2F5, C2F5, C3F7, C4F9)

Synthesis and Properties of Tetrakis(Perfluoroalkyl)Tellurium Te(R_f)₄ (R_f = CF₃, C₂F₅, C₃F₇, C₄F₉) Te(CF₃)₄ is obtained from the reaction of Te(CF₃)Cl₂ with Cd(CF₃)₂ complexes as a complex with e. g. CH₃CN, DMF. It is a light and temperature sensitive hydrolysable liquid. The reaction with fluorides yields the complex anion [Te(CF₃)₄F]⁻, with fluoride ion acceptors the complex cation [Te(CF₃)₃]⁺. With traces of water an acidic solution is formed. Te(CF₃)₄ acts as a trifluoromethylation reagent. The reaction with XeF₂ gives hints for the formation of Ye(CF₃)₄F₂. Properties and NMR spectra are discussed. The much more stable complexes of Te(R_f)₄ (R_f = C₂F₅, C₃F₇, C₄F₉) are formed from the reaction of TeCl₄ with the corresponding Cd(R_f)₂ complexes.     

Trivalent-pentavalente Phosphorverbindungen/Phosphazene. IV. Darstellung und Eigenschaften neuer N-silylierter Diphosphazene

Trivalent-Pentavalent Phosphorus Compounds/Phosphazenes. IV. Preparation and Properties of New N-silylated Diphosphazenes Phosphazeno-phosphanes, R₃P = N? P(OR′) ₂ (R = CH₃, N(CH₃)₂; R′ = CH₂? CF₃) react with trimethylazido silane to give N-silylated diphosphazenes, R₃P = N? P(OR′)₂ = N? Si(CH₃)₃ compounds decompose by atmospherical air to phosphazeno-phosphonamidic acid esters, R₃ P?N? P(O)(O? CH₂? CF₃)(NH₂). Thermolysis of diphosphazene R₃P = N? P(OR′) ₂ = N? Si(CH₃)₃ (R = CH₃, R′ = CH₂? CF₃) produces phosphazenyl-phosphazenes [N?P(N?P(CH₃)₃)OR′] _n. The compounds are characterized by elementary analysis, IR-, ¹H_-, ²⁹Si-, ³¹P-n.m.r., and mass spectroscopy.     

Coordination of the new weakly coordinating anions Al(OCH(CF3)2)4−, Al(OC(CH3)(CF3)2)4−, and Al(OC(Ph)(CF3)2)4− to the monovalent metal ions Li+ and Tl+

The structures of Li⁺ or Tl⁺ salts of three new fluoroalkoxide-containing aluminate anions were determined by X-ray crystallography. For LiAl(OC(Ph)(CF₃)₂)₄, monoclinic, C2/c, a=42.297(6), b=10.641(1), c=19.132(2) Å, β=114.808(9)°, Z=8, T=−100°C, R=0.052; for TlAl(OC(CH₃)(CF₃)₂)₄, monoclinic, P2₁/c, a=12.650(3), b=9.970(2), c=21.237(4) Å, β=94.00(3)°, Z=4, T=−100°C, R=0.073; for TlAl(OCH(CF₃)₂)₄, monoclinic, P2₁/n, a=14.261(1), b=9.8024(9), c=16.911(2) Å, β=93.467(8), Z=4, T=−130°C, R=0.053. The monatomic, monovalent cations interact with their respective anions by means of M–O and M–F bonds. The Tl⁺ cations in TlAl(OCH(CF₃)₂)₄ and TlAl(OC(CH₃)(CF₃)₂)₄ interact with three different aluminate anions. The Li⁺ cation in LiAl(OC(Ph)(CF₃)₂)₄ interacts with only one aluminate anion, forming a rare trigonal–prismatic LiO₂F₄ coordination unit.     

Solvents effects in reactions between perfluoroalkyliodides and cadmium

The interaction between perfluoroorgano iodides (R_fI where R_f = F(CF₃)₂C(CF₂CF₂)₃, n-C₆F₁₃,n-C₈F₁₇, F(CF₃)₂COCF₂CF₂,F(CF₃)₂CO(CF₂CF₂)₄ andC₂H₅OC(O)(CF₂CF₂) with cadmium in an acetonitrilesolvent media produces primarily the coupled products (R_fR_f,72–90% yield) in addition to minor quantities of the reduction products (R_fH). On the other hand ICF₂CF₂I and C1CF₂CFC1I, by a 1,2-dehalogenation reaction, form the olefins CF₂ = CF₂ and CF₂ = CFC1, respectively, as the principal products. The interaction of R_fI compounds with cadmium in other solvent media, e.g. diethyl ether. tetrahydrofuran (THF), N,N-dimethylformamide (DMF), and bis(2-methoxyethyl)ether(diglyme) were examined and found to produce a different ratio of R_fR_f and R_fH products. {ft*}Present address: Fluidics Inc., P.O.Box 1886, Dayton, OH 45429 U.S.A.     

Advances in Trifluoromethylating Phosphorus Compounds

Abstract

The System CF₃I/Me₃P is re-investigated and Me₂PCF₃, Me₄P⁺γ, (CF₃)₂PMe₃, Me₃PI₂, [Me₃(CF₃)P]⁺γ are found as products. Using CF₃Br/P(NEt₂)₃ the phosphines R¹ ₂PCF₃ and R¹P(CF₃)₂ (e.g. R¹ = Me, iPr, NEt₂) can be obtained which are precursors either for phosphoranes (e.g. 1,2λ⁵σ⁵-oxaphosphetanes) or phosphonium salts (e.g. [R¹ ₂(Me)PCF₃]⁺X^? or [R¹(Me)P(CF₃)₂X^?]. The latter are deprotonated to furnish methylene phosphoranes R¹ ₂(CH₂=)PCF₃ or R¹(CH₂=)P(CF₃)₂, reactive synthons. From CF₃Br/P(NEt₂)₃/P(OPh)₃ the phosphine P(CF₃)₃ is available, which turned out to be a potent electrophile. Amido phospites ROP(NEt₂)₂ and halides R²X (R²=CCl₂CF₃, X=Cl; R²=CF=CFCF₃, X=F; R²=C₆F₅, X=Br, I; R²=C(CF₃)₃, X=Br; R²=SCF₃, X=CF₃) undergo an ARBUZOV reaction.     

Haloacetylated enol ethers. 14 [6]. Reaction of β-alkoxyvinyl trifluoromethyl ketones with N-methylhydroxylamine

The reaction of a series of β-methoxyvinyl trifluoromethyl ketones [CF₃COC(R²)?C(OMe)R¹, where R¹ = Me, -(CH₂)₃-C3, -CH₂)₄-C3, Ph and R² = H, Me, -(CH₂)₃-C4, -(CH₂)₄-C4] with N-methylhydroxylamine is reported. The regiochemistry of the reaction are explained by MO calculation data.     

Über die Umsetzung von NN-Dihalogenperfluoralkanaminen mit Schwefel und Schwefelderivaten

Reactions of NN-Dihaloperfluoroalkaneamines with Sulfur and Sulfur Derivatives Reactions of NN-Dihaloperfluoroalkaneamines R_fNX₂ (R_f = CF₃, C₂F₅; X = Cl, Br) with S₈, S₄N₄ and A = SX₂ (A = R_fN, O) are described. The products isolated are: Sulfurdihalideimides R_fNSX₂ (R_f = CF₃, C₂F₅; X = Cl, Br), Sulfurdiimides R_fNSNR_f and Bis(sulfurdiimido)sulfides (R_fNSN)₂S(R_f = CF₃, C₂F₅). Thionylimides R_fNSO were not obtained in preparative quantities.     

Fluoroalkyl Radical Generation by Homolytic Bond Dissociation in Pentacarbonylmanganese Derivatives

Thermal decarbonylation of the acyl compounds [Mn(CO)₅(COR_F)] (R_F=CF₃, CHF₂, CH₂CF₃, CF₂CH₃) yielded the corresponding alkyl derivatives [Mn(CO)₅(R_F)], some of which have not been previously reported. The compounds were fully characterized by analytical and spectroscopic methods and by several single-crystal X-ray diffraction studies. The solution-phase IR characterization in the CO stretching region, with the assistance of DFT calculations, has allowed the assignment of several weak bands to vibrations of the [Mn(¹²CO)₄(eq-¹³CO)(R_F)] and [Mn(¹²CO)₄(ax-¹³CO)(R_F)] isotopomers and a ranking of the R_F donor power in the order CF₃<CHF₂<CH₂CF₃≈CF₂CH₃. The homolytic Mn−R_F bond cleavage in [Mn(CO)₅(R_F)] at various temperatures under saturation conditions with trapping of the generated R_F radicals by excess tris(trimethylsilyl)silane yielded activation parameters ΔH^≠ and ΔS^≠ that are believed to represent close estimates of the homolytic bond dissociation thermodynamic parameters. These values are in close agreement with those calculated in a recent DFT study (J. Organomet. Chem. 2018 , 864, 12–18). The ability of these complexes to undergo homolytic Mn−R_F bond cleavage was further demonstrated by the observation that [Mn(CO)₅(CF₃)] (the compound with the strongest Mn−R_F bond) initiated the radical polymerization of vinylidene fluoride (CH₂=CF₂) to produce poly(vinylidene fluoride) in good yields by either thermal (100 °C) or photochemical (UV or visible light) activation.     

Reactions of tetralouroethene oligomers Part 6. Some reactions of 4-diazo-1,1,1,2,2-pentaflouro-3-pentaflouethyl-3-triflouromethylbutane

The isocyanate R_fCH₂NCO (R_f=CF₃(C₂F₅)₂C)reacts under strongly acidic conditions to form the salt R_fCH₂NH₃⁽⁺⁾HSO₄⁽⁻⁾(1) which yields, on treatment with sodium nitrite the diazaoalkane R_fCHN₂ (3). Dissolution of (1) in D.M.S.O. gives, by a remarkable decomposition reaction, the alkane R_fH (2). Reaction of (3) with excess sodium nitrite affords the isocyanate R_fNCO (4) which is stable to water,but which reacts with ammia to give the urea R_fNHCONH₂ (5); this latter was not readily hydrolysed .Photolysis of (3) yields the diazadiene R_fCHNNCH R_f (7). Thermolysis of (3) alone afforded the diazadiene (7), but reaction in the presence of copper (II) perchlorate afforded (7) and the aldehyde R_fCHO (6)     

Synthesis and coordination chemistry of perfluoroalkyl-derivatised β-diketonates

A series of fluorinated β-diketones, R_fC(O)CH₂C(O)R_f′ (R_f=C₆F₁₃, R_f′=CF₃; R_f=R_f′=C₆F₁₃, C₇F₁₅), have been prepared in reasonable yields by a two-step synthesis. On reaction with appropriate metal substrates, deprotonation and concurrent coordination of the perfluoroalkyl-derivatised β-diketonate ligands affords a range of fluorous metal complexes which have been characterised by elemental analysis, mass spectrometry, IR and NMR spectroscopies. The structures of [Cu(L-L)₂(H₂O)₂] {L-L=CF₃C(O)CHC(O)C₆F₁₃, C₆F₁₃C(O)CHC(O)C₆F₁₃} and [Cu(PPh₃)₂{C₇F₁₅C(O)CHC(O)C₇F₁₅}] have been determined by single-crystal X-ray diffraction.     

Transition metal catalyzed alternating copolymerizations of olefins and co

Well defined Pd(II) catalysts of the type (N′N)Pd(CH₃)(Solv.)⁺ B(Ar_f)₄- (Ar_f = −3, 5-(CF₃)₂C₆H₃) have been prepared for living alternating copolymerizations of olefins with CO. This talk will focus on the mechanistic details of chain growth as elucidated by ¹H and ¹³C NMR spectroscopy, model studies of key migratory insertion steps and synthesis and properties of various copolymers and block copolymers based on styrenes, CH₂=CHC₆H₄X [X = p-C(CH₃)₃, p-OC(O)CH₃, p-OC(O)C-t-Bu), p-NHC(O)(C-t-Bu)]. Use of the catalysts based on the C₂ symmetric, homochiral ligand 2, 2'-bis[2-[4(S)-(Alkyl)-1, 3-oxazolinyl]]propane [Alkyl = CH₃, CH(CH₃)₂] produces a copolymer, 1, with a highly isotactic microstructure and high optical activity in contrast to achiral ligands such as 1,10-phenanthroline which produce copolymers with predominantly syndiotactic microstructure.     

Aminophosphite und Aminophosphorane mit der 2,2,2-Trifluor-1-(trifluormethyl)ethyl-Gruppierung

Aminophosphites and Aminophosphoranes Containing the 2,2,2-Trifluoro-1-(trifluoromethyl)ethyl Grouping By the reaction of dichloroaminophosphines R₂NPCl₂ (R = Me, Et, SiMe₃; R₂ = CH₂(CH₂CMe₂)₂) and LiOCH(CF₃)₂ the phosphites 1 – 4 and LiCl were formed. Hexafluoroacetone reacted with 1 or 2 to give the monocyclic phosphoranes 5 and 7 . Compound 5 could also be obtained from the dichloroaminophosphosphorane 6 and LiOCH(CF₃)₂. The aminophosphite 2 , elementary chlorine and Li₂[OC(CF₃)₂C(CF₃)₂O] or LiOCH(CF₃)₂ gave 7 or the acyclic phosphorane 8 , respectively. Compounds 1 – 4 exhibit two magnetically inequivalent CF₃ groups in the ¹⁹F-N.M.R. spectra, the phosphoranes 5 , 7 and 8 show no ligand permutation at room temperature.     

Regioselectivity of reactions of vinyl- and isopropenylcyclopentadienide anions with electrophilic agents. Synthesis and crystal structures of complexes [C5H4C(Me)=CH2]ZrCl3 · 2THF and [C5Me4CH=CH2]ZrCl3 · 2THF

Regioselectivity of the reactions of lithium vinyl- and isopropenylcyclopentadienides C₅H₄C(R)=CH₂ ^-Li⁺(R = H, Me) and lithium tetramethylvinylcyclopentadienide C₅Me₄CH=CH₂ ^-Li⁺ with various electrophilic agents (Me₃SiCl, Me₃SnCl, Et₂PCl, 2-chloro-1, 3-dioxaphospholane, and MeI) was studied. Two new monocyclopentadienyl zirconium complexes, [C₅H₄C(Me) = CH₂]ZrCl₃ · 2THF and [C₅Me₄CH=CH₂]ZrCl₃ · 2THF, were synthesized. Their crystal structures were established by X-ray diffraction. The results of quantum chemical calculations for the C₅H₄C(R) = CH₂ ^- (R = H, Me) and C₅Me₄CH=CH₂ ^- anions by the DFT method (RMPW1PW91) with the 6-311+G(d, p) split valence basis set are in good agreement with experimental data on the regioselectivity of their reactions with electrophilic agents.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 390–399, February, 2005.