Syntheses,structures and catalytic properties of new mononuclear terpyridine-manganese(II) complexes with tetraphenylimido-diphosphinate and diphenylphosphinate ligands

Treatment of manganese(II) acetate tetrahydrate [Mn(CH3COO)₂·4H₂O] with one equivalent of 2,2′:6′,2′′-terpyridine (terpy) and two equivalents of potassium tetraphenylimido-diphosphinate K[N(Ph₂PO)₂] in methanol afforded a mononuclear manganese(II) complex, [(terpy)Mn{η¹-O-N(Ph₂PO)₂}₂(H₂O)] (1), with two terminal [N(Ph₂PO)₂]– ligands. Interaction of [Mn(CH₃COO)₂·4H₂O] with one equivalent of terpy in the presence of both K[N(Ph₂PO)₂] and Ph₂PO₂K in methanol gave a mononuclear manganese(II) complex [(terpy)Mn(η¹-O-O₂PPh₂){N(Ph₂PO)₂}] (2) with a chelated [N(Ph₂PO)₂]– ligand. Treatment of manganese(II) dichloride tetrahydrate [MnCl₂·4H₂O] with three equivalents of K[N(Ph₂PO)₂] in methanol resulted in isolation of a mononuclear manganese(III) complex [Mn{η¹-O-N(Ph₂PO)₂}-{N(Ph₂PO)₂}₂] (3) with one terminal and two chelated [N(Ph₂PO)₂]– ligands. Reaction of [Mn(CH₃COO)₂·4H₂O] with one equivalent of 4′-phenyl-[2,2′:6′,2′′]-terpyridine (4-Ph-terpy) and two equivalents of Ph₂PO₂K in methanol gave [(4-Ph-terpy)Mn(η¹-O-O₂PPh₂)₂(H₂O)] (4) with a labile water molecule. Complexes 1–4 have been spectroscopically characterized and their structures have been established by single-crystal X-ray diffraction. Catalytic behavior of 1 and 4 for sulfide oxidation was also investigated.     

Stereoselective synthesis of anti-2-oxazolidinones by Ph3P-CCl4-Et3N mediated SN2 cyclization of N-Boc-β-amino alcohols

Ethyl anti-4-substituted phenyl-2-oxo-1,3-oxazolidine-5-carboxylates were synthesized stereoselectively in excellent yields using the Ph₃P-CCl₄-Et₃N system by S_N2 cyclization of N-Boc-β-amino alcohols. syn to anti conversion of ethyl 4-substituted phenyl-2-oxo-1,3-oxazolidine-5-carboxylates using DBU as base is also described.     

Selected Reactions on (R)Ph2PN?S3N3 Heterocycles: Exploration of chemical behavior and reactivity

Reactions of (R)Ph₂PN? S₃N₃ heterocycles with olefins such as norbornadiene, norbornene and dicyclopentadiene have yielded different results. Like Ph₃PN? S₃N₃, (R)Ph₂PN? S₃N₃ (R = C₄H₈N? , C₅H₁₀N? , C₆H₁₂N? , CH₃NC₄H₈N? and OC₄H₈N? ) compounds have given the cycloaddition products (R)Ph₂PN? S₃N₃ · C₇H₈ (yield 41 - 62%) with norbornadiene, while norbornene and dicyclopentadiene have not produced the corresponding adducts under identical conditions. With Ph₃PN? S₃N₃ both norbornene and dicyclopentadiene have given the ring expanded heterocycle, 1,5-[Ph₃PN]₂S₄N₄ in ca. 65% yield. The solution phase decomposition studies of (secondary amino) Ph₂PN? S₃N₃ derivatives have lead to the formation of (R)Ph₂PNH₂⁺X^?, while (primary amino) Ph₂PN? S₃N₃ has given Ph₂PS₂N₃ heterocycle in ca. 80% yield. Acid hydrolysis of (R)Ph₂PN? S₃N₃ derivatives has resulted in the isolation of Ph₂P(O)OH in all the cases, where R is an amino group.     

Cyclic S?N compounds and phosphorus reagents: Part X. Synthesis and characterization of phosphinimino-substituted S?N heterocycles

Room temperature reactions of S₄N₄ with (amino) diphenylphosphines, (R)Ph₂P, have basically yielded two different types of S N heterocycles under two different stoichiometric conditions. Phosphiniminocyclotrithiatriazenes, (R)Ph₂PN S₃N₃ (R = C₄H₈N , C₅H₁₀N , C₆H₁₂N , CH₃NC₄H₈N , (C₆H₁₁)₂ N , and (C₆H₅CH₂)₂N ) have been obtained (yield 45–76%) from a 1:2 mole ratio (S₄N₄:(R)Ph₂P) reaction, while the disubstituted S₄N₄ derivatives, 1,5-[Ph₂(R)PN]₂S₄N₄ (R = C₄N₈N , C₅H₁₀N , and C₆H₁₂N ) have been obtained (yield 30–45%) only from a 1:3.5–4 mole ratio reaction. All the 1,5-[Ph₂(R)PN]₂S₄N₄ derivatives prepared in this study undergo a room temperature solution phase transformation to the corresponding (R)Ph₂PN S₃N₃ heterocycles.     

Metall-Schwefelstickstoff-Verbindungen. 22. S4N3Cl als Ausgangsprodukt zur Herstellung von Komplexen mit dem S3N−-Liganden Die Komplexe [Ph6P2N][Cu3(S3N)2(CN)2]und [Ph4As][(CuS3N)2(CN)]

The reaction of S₄N₃Cl with metal salts leads to complexes containing the S₃N^?chelating ligand, a reaction which proceeds smoothly especially in an alkaline medium. Thus we were able to prepare, by the reaction of CuCN with S₄N₃Cl and [Ph₆P₂N]OH (Ph = phenyl), the salt [Ph₆P₂N][Cu₃(S₃N)₂(CN)₂], a compound in which the anions build a bidimensional network through supplementary Cu - S contact interactions. The salt is monoclinic, space group C2/c, a = 18.960, b = 14.651 and c = 15.400 Å, β = 101.03° and Z = 4. Metal Sulfur Nitrogen Compounds. 22. S₄N₃Cl as a Starting Compound for the Preparation of Complexes Containing the S₃N^? Ligand. Complexes [Ph₆P₂N] [Cu₃(S₃N)₂ (CN)₂] and [Ph₄As] [(CuS₃N)₂ (CN)] In contrast, the reaction of CuN with S₄N₃Cl and [Ph₄As]OH led to the compound [Ph₄As][(CuS₃N)₂(CN)], monoclinic, space group C2/c, a = 18.478, b = 6.405, c = 27.051 Å, β = 119.50°, Z = 4. In the centrosymmetric anion the two Cu(S₃N) groups are linked together by disordered CN^? groups. An additional linkage results from Cu - Cu contact interactions, with d = 2.84 Å.     

Synthesis and reactivity of N-hydroxy-2-aminoindoles

Catalytic hydrogenation of (2-nitrophenyl)acetonitriles bearing an electron-withdrawing substituent α to the nitrile, using Pd/C and (Ph₃P)₄Pd, affords N-hydroxy-2-aminoindoles in good to excellent yields. (Ph₃P)₄Pd decreases the reduction rate of the intermediate hydroxylamine and acts as a catalyst during the cyclization onto the nitrile.     

Easy Access to the Copper(III) Anion [Cu(CF3)4]−

CuCl or pre‐generated CuCF₃ reacts with CF₃SiMe₃/KF in DMF in air to give [Cu(CF₃)₄]^? quantitatively. [PPN]⁺, [Me₄N]⁺, [Bu₄N]⁺, [PhCH₂NEt₃]⁺, and [Ph₄P]⁺ salts of [Cu(CF₃)₄]^? were prepared and isolated spectroscopically and analytically pure in 82–99 % yield. X‐ray structures of the [PPN]⁺, [Me₄N]⁺, [Bu₄N]⁺, and [Ph₄P]⁺ salts were determined. A new synthetic strategy with [Cu(CF₃)₄]^? was demonstrated, involving the removal of one CF₃^? from the Cu atom in the presence of an incoming ligand. A novel Cu^III complex [(bpy)Cu(CF₃)₃] was thus prepared and fully characterized, including by single‐crystal X‐ray diffraction. The bpy complex is highly fluxional in solution, the barrier to degenerate isomerization being only 2.3 kcal mol^?1. An NPA study reveals a huge difference in the charge on the Cu atom in [Cu(CR₃)₄]^? for R=F (+0.19) and R=H (+0.46), suggesting a higher electron density on Cu in the fluorinated complex.     

Substitutions- und Oxydationsreaktionen des N-Dichlorphosphanyl-triphenylphosphazens,Ph3PN?PCl2

Replacement and Oxidation Reactions of N-Dichlorophosphanyl Triphenylphosphazene, Ph₃P?N? PCl₂ The title compound ( 1 ) reacts with MeOH, EtOH, PhOH, EtSH, and water forming N-phosphanyl or N-phosphinoyl phosphazenes, resp., Ph₃P?N? PX₂ (X ? OPh( 8 ), SEt( 9 )) or Ph₃P?N? PH(O)X (X ? Cl( 3 ), OH( 4 ), OMe( 5 ), OEt( 7 )). The reaction of 1 with P(NEt₂)₃ yields Ph₃P?N? P(NEt₂)₂ ( 10 ). Ph₃P?N? PF₂( 11 ) and Ph₃P?N? PH(O)F ( 12 ) are obtained by chlorine-fluorine exchange. The N-phosphanyl compounds 1 , 8 , 9 and 11 are oxidized by NO₂ yielding the corresponding N-phosphoryl derivatives, Ph₃P?N? P(O)X₂ (X ? Cl( 2 ), OPh( 13 ), SEt ( 14 ), F( 15 )). The thiophosphoryl compounds, (Ph₃P?N? P(S)X₂ (X ? Cl( 16 ), OPh( 17 ), F( 18 )) are obtained by oxidizing 1 , 8 , and 11 with sulfur.     

SYNTHESIS AND CHARACTERIZATION OF THE FIRST BORANE ADDUCTS AND BORON CATIONS OF SOME N-ALKYL AND N-AMINOTRIPHENYLPHOSPHORANIMINES

Abstract

The first borane adducts of N-alkyl and N-aminotriphenylphosphoranimines, Ph₃P[dbnd]N—R, were prepared by two different general synthetic methods. The first method involved displacement of THF (tetrahydofuran) from THF-borane by the free imines, and the second employed the reaction of LiBH₄ with iminium bromides, Ph₃P[dbnd]N(R)HBr, in diethyl ether. Imine boranes, Ph₃P[dbnd]N(R)BH₃, were synthesized where R [dbnd] methyl, ethyl, n-propyl, isopropyl, isobutyl, t-butyl. dimethylamino, phenylamino, and methyl, phenylamino as the nitrogen attached groups. Symmetrical boron cations, (Ph₃P[dbnd]NR)₂, BH₂ ⁺, where R = methyl, ethyl, and n-propyl, were synthesized by displacement of iodide from in-situ generated iodoborane adducts, Ph₃P[dbnd]N(R)BH₂I, by the free imines. An attempt to form an unsymmetrical boron cation from (CH₃)₃ NBH₂I and Ph, P[dbnd]N(n-C₃H₇) resulted only in a mixture of the corresponding symmetrical boron cations. Physical, chemical and spectral properties of the borane adducts and boron cations, namely thermal and hydrolytic stabilities, infrared and NMR data are presented. Oxidative and reductive stabilities of the boron cations were studied. The borane adducts can be chlorinated with either HCI or Ph₃CCI. Relative base strengths of some imines were determined by following the exchange of BH₃ between borane adducts of (CH₃)₃ N or 4- (CH₃)C₅H₄ N and the imines via NMR.     

The Preparation and X-Ray Structure of [AsPh4][Ph2P(S)NSiMe3] · 0.5 THF

The reaction of Ph₂P(S)N(SiMe₃)₂ with potassium tert-butoxide in a 1:1 molar ratio produces K[Ph₂P(S)NSiMe₃], which was converted to the AsPh₄⁺ salt by metathesis with [AsPh₄]Cl. The X-ray crystal structure of [AsPh₄][Ph₂P(S)NSiMe₃] · 0.5 THF consists of noninteracting AsPh₄⁺ and Ph₂P(S)NSiMe₃^? ions with d(P? S) = 1.980(4) Å and d(P? N) = 1.555(8) Å. The PNSi bite angle in the anion is 136.3(5)°. Electrophilic attack by Ph₂P(S)Cl occurs at the sulfur atom of Ph₂P(S)NSiMe₃^?. The oxidation of the anion with iodine produces a disulfide which regenerates K[Ph₂P(S)NSiMe₂] upon treatment with potassium tert-butoxide.     

Promoting effect of ionic liquids on ligand substitution reactions

Ionic liquid solvents N-hexylpyridinium bistrifylimide ([C₆pyr][Tf₂N]] and 1-butyl-3-methylimidazolium hexafluorophosphate ([C₄mim][PF₆]) promoted the displacement of anionic ligands by pyridine derivatives in trans-(Ph₃P)₂Rh(CO)NO₃ to a much greater extent than did dichloromethane. Thus, addition of a slight excess of 2-fluoropyridine to trans-(Ph₃P)₂Rh(CO)NO₃ in [C₄mim][PF₆] gave a 29:71 product mixture of trans-(Ph₃P)₂Rh(CO)NO₃:[trans-(Ph₃P)₂Rh(CO)(2-fluoropyridine)][NO₃], while the ratio was 91:9 in dichloromethane.     

Kinetics of Oxidation of Diphenylmethane and Derivatives with Ce(IV) in Aqueous Acidic Acetonitrile

In aqueous acidic acetonitrilc solution cerium(IV) oxidizes diphenylmethane (Ph₂CH₂) to produce diphenylmethanol (Ph₂CHOH) first and then benzophenone (Ph₂CO). With the organic reductant in great excess, both the Ce(IV)-Ph₂CH₂ and Ce(IV)-Ph₂CHOH rcactions follow second-order kinetics. The rates of both reactions increase nonlinearly with increasing [H⁺] or with decreasing [H₂O]. Both kinetic and spectrophotometrc results indicate that replacement of water molecules by complex formation through the phenyl or hydroxyl group plays an important role in activating the reaction. Under similar conditions, the order of relative reactivities toward Ce(IV) oxidation is PhCH₂OH > CH₃CH₂OH > Ph2CHOH > Ph₂CH₂ > PhCH₃> (Ph₂CO, C₆H₆). Mechanistic interpretations of the kinetic results are presented.     

Organometallic compounds having metal-metal bonds : XXIII. Hydrido(triphenylgermanium)tetracarbonyliron and its conjugate base

Reaction of Ph₃GeLi with [Et₄N][HFe₃(CO)₁₁] affords the new carbonylferrate salt [Et₄N][Ph₃GeFe(CO)₄] and the same reaction provides an alternative route to the known silicon and tin analogs. Protonation of [Et₄N][Ph₃GeFe(CO)₄] with HCl in ether-THF forms the air-sensitive, thermally rather unstable cis-Ph₃GeFeH(CO)₄. The latter protonates chloride ions in dichloromethane.     

The Synthesis,Characterisation, and Reactivity of Some Polydentate Phosphinoamine Ligands with Benzene‐1,3‐diyl and Pyridine‐2,6‐diyl Backbones

The polydentate phosphinoamines 1,3‐{(Ph₂P)₂N}₂C₆H₄ and 2,6‐{(Ph₂P)₂N}₂C₅H₃N have been prepared in a single step from the reaction of the amines 1,3‐(NH₂)₂C₆H₄ or 2,6‐(NH₂)₂C₅H₃N with Ph₂PCl in presence of Et₃N (1 : 4 : 4 molar ratio) in CH₂Cl₂. Reaction of 1,3‐{(Ph₂P)₂N}₂C₆H₄ or 2,6‐{(Ph₂P)₂N}₂C₅H₃N with elemental sulfur or selenium in CH₂Cl₂ affords the corresponding tetrasulfide or tetraselenide, respectively, in good yield. The complexes [1,3‐{Mo(CO)₄(Ph₂P)₂N}₂(C₆H₄)] and [2,6‐{Mo(CO)₄(Ph₂P)₂N}₂(C₅H₃N)] were prepared from the reaction of these phosphinoamines with [Mo(CO)₄(nbd)] (nbd=norbornadiene) in toluene, and the structure of the latter complex has been determined by single‐crystal X‐ray diffraction analysis.     

Phosphaniminato-Komplexe des Iods. Synthese und Kristallstrukturen von Ph3PNIO2 und Ph3PNSiMe3 · I2

Phosphoraneiminato Complexes of Iodine. Syntheses and Crystal Structures of Ph₃PNIO₂ and Ph₃PNSiMe₃ · I₂ Ph₃PNIO₂ has been prepared as yellow crystals by the reaction of Ph₃PNSiMe₃ with I₂O₅ in boiling acetonitrile, whereas the molecular complex Ph₃PNSiMe₃ · I₂ is formed as brown crystals by the reaction of Ph₃PNSiMe₃ with iodine in acetonitrile solution. Both complexes were characterized by crystal structure determinations. Ph₃PNIO₂: Space group P2₁/n, Z = 4, 2 858 observed unique reflections, R = 0.039. Lattice dimensions at 19°C: a = 972.8(2), b = 1 743.4(3), c = 1 073.7(2) pm, β = 115.46(3)°. The compound forms monomeric molecules with pyramidal geometry at the iodine atom. The bond angle PNI (126.9°) is unusually small; the PN bond length of 159.2 pm corresponds with a double bond. Ph₃PNSiMe₃ · I₂: Space group P1 , Z = 2, 3 560 observed unique reflections, R = 0.033. Lattice dimensions at 19°C: a = 941.2(2), b = 1 041.7(2), c = 1 287.4(3) pm, α = 78.34(1)°, β = 72.00(2)°, γ = 86.08(2)°. The compound forms monomeric molecules, in which the I₂ molecule and the nitrogen atom of the phosphoraneimine molecule realize a linear N? I? I axis with a bond length N? I of 243.2 pm.     

Tetraphenylboroxinate(1-) salts of monoborate cations: Synthesis and single-crystal X-ray structures of [Ph2B{OCH2CH2N(Me)(CH2)n}2][Ph4B3O3] (n = 4, 5)

The salts, [Ph₂B{OCH₂CH₂N(Me)(CH₂)_n}₂][Ph₄B₃O₃] (n = 4, 5), were prepared in moderate yields in MeOH solution from reaction of Ph₂BOBPh₂ with [N(CH₂)_n(Me)(CH₂CH₂OH)][OH] and PhB(OH)₂ in a 1:2:4 ratio. The reactions also lead to Ph₃B₃O₃. Both salts were characterized by NMR (¹H, ¹³C, ¹¹B) IR, and single-crystal XRD studies. The salts are comprised of cationic monoborates (zwitterionic, 2N⁺ and 1B⁻) and tetraphenylboroxinate anions.     

Synthese von Nitrenkomplexen mit N-Trimethylsilylanilin. II. Charakterisierung und Kristallstruktur der Rhenium(V)-phenylnitren-Komplexe mer-[Re(NPh)Cl3(NH2Ph)(Ph3P)] und trans-[Re(NPh)(OMe)Cl2(Ph3P)2]

Synthesis of Phenylnitrene Complexes with N-Trimethylsilylaniline. II. Characterization and Crystal Structure of the Rhenium(V) Complexes mer-[Re(NPh)Cl₃(NH₂Ph)(Ph₃P)] and trans-[Re(NPh)(OMe)Cl₂(Ph₃P)₂] Reaction of [ReOCl₃(Ph₃P)₂] with N-trimethylsilylaniline yields mer-[Re(NPh)Cl₃(Ph₃P)₂], which reacts under air with excess of N-trimethylsilylaniline to form [Re(NPh)Cl₃ · (NH₂Ph)(Ph₃P)]. Crystallization from CH₂Cl₂/MeOH affords [Re(NPh)(OMe)Cl₂(Ph₃P)₂] as an additional product. [Re(NPh)Cl₃(NH₂Ph)(Ph₃P)] crystallizes in the monoclinic space group P2₁/n with a = 1 192.3(3); b = 1 918.9(3); c = 1 266.3(3) pm; β = 101.71(1)°; Z = 4. The rhenium atom has a distorted octahedral environment with the Cl atoms in meridional positions. The phenyl nitrene ligand is coordinated with an almost linear arrangement Re? N1? C40 = 166.8(6)° and with a bond distance Re?N = 170.5(6) pm. [Re(NPh)(OMe)Cl₂(Ph₃P)₂] · 1/2CH₂Cl₂ crystallizes in the triclinic space group P1 : a = 1 103.1(4); b = 1 227.9(4); c = 1 711.3(5) pm; α = 70.48(3)°; β = 72.71(3)°; γ = 80.03(3)°; Z = 2. The rhenium atom exhibits a distorted octahedral coordination with the Cl atoms and the phosphine ligands in trans positions. As a consequence of the competition of the nitrene ligand and the trans-coordinated methoxy group the Re?;N bond length is slightly lengthened to 173.2(7) pm, while the Re? O bond length of 193.4(6) pm is short. The bond angles Re? N? C70 and Re? O? C80 are 173.3(7)° and 139.1(7)°, respectively.     

Substituierte halogenocarbonylmetallate des chroms,molybdäns und wolframs : III. Ligandensubstitution an halogenocarbonylmetallaten der VI. Nebengruppe

The halopentacarbonylmetal compounds of molybdenum and tungsten react with phosphines in polar aprotic solvents with CO substitution to give the ionic derivatives [LM(CO)₄X]^? (X = Cl, Br; M = Mo, W; L = i-Pr_nPh_3?nP, (Me₂N)_nPh_3?nP, (i-PrO)_nPh_3?nP, Ph₂MeP, Et₃P, (PhO)₃P, n = 0, 1, 2, 3). The substitution of the halide ligand, which is catalysed by protic solvents, provides a convenient route to the neutral complexes LM(CO)₅ and LL′M(CO)₄ (L = phosphines; L′ = ammonia, acetonitrile, pyridine, piperidine). cis-(NH₃)(i-Pr₃P)W(CO)₄ in solution is slowly deuterated by D₂O. In this reaction all three hydrogen atoms appear to be exchanged simultaneously.     

Darstellung und Eigenschaften von Tris(diphenylamino)-phosphin

Preparation and Properties of Tris (diphenylamino) Phosphine The synthesis and some properties of tris(diphenylamino)phosphine are described. Displacement of the chlorine atom is readily achieved by reaction of (Ph₂N)₂PCl with Ph₂NSime₃. Thus tris(diarylamino)phosphine (Ph₂N)₃P is obtained almost in quantitativ yield. The aminolysis reaction of PCl₃ or (Ph₂N)₂PCl with Ph₂NH gives also (Ph₂N)₃P. The properties and structure of the phosphine on basis of spectroscopical and X-ray investigations are discussed.     

The direct deprotonation of the η5-pyrrolyl ligand in (η5-C4H4N)(Ph3P)2ReH2

Treatment of (η⁵-C₄H₄N)(Ph₃P)₂ReH₂ (C₄H₄N = pyrrolyl) with n-BuLi at −78°C leads to regioselective (α-position) ring deprotonation. Reaction of the deprotonated product with RI (R = Me, n-Bu) gives (η⁵-2-RC₄H₃N)(Ph₃P)₂ReH₂ in high yield.