BIS(TRICHLOROMETHYL)CARBONATE,AN EFFICIENT ACTIVATOR FOR THE ONE-POT CONVERSION OF ALDEHYDES INTO NITRILES UNDER MILD CONDITIONS*

ABSTRACT

A single step conversion of aldehydes into the corresponding nitriles has been achieved in high yields using stoichiometric amounts of NH₂OH?HCl, Et₃N and bis(trichloromethyl)carbonate at room temperature.

     

FRIEDEL-CRAFTS REACTION OF BIS(TRICHLOROMETHYL)CARBONATE FOR THE PREPARATION OF BENZOPHENONES

ABSTRACT

Benzophenones (RC₆H₄COC₆H₄R, R=H, Cl, CH₃ or (CH₃)₂N) have been prepared by the Friedel-Crafts reactions of aromatic compounds C₆H₅R with bis(trichloromethyl)carbonate (BTC) instead of toxic phosgene. ACl₃, FeCl₃ or ZnCl₂ were used as Lewis acids in the reaction. The preparation is safe, convenient and in higher yields than phosgene-processes.     

Specific Interactions and the Nature of the Chemical Nonequivalence of Chlorine Atoms in the ECl<Subscript>3</Subscript> Group (E = C,P) of Trichlorophosphonium Ylides and Isomeric Dichloro(trichloromethyl)phosphine

The nature of the asymmetry of the ECl₃ group (E = C, P) in dichloro(trichloromethyl)phosphine and trichlorophosphonium methylide and dichloromethylide was studied by nonempirical and MNDO-PM3 calculations and ³⁵Cl NQR spectroscopy. The chemical nonequivalence of chlorine atoms in the CCl₃ group of dichloro(trichloromethyl)phosphine is caused by steric interaction with the PCl₂ fragment. In the PCl₃ group of trichlorophosphonium methylide and dichloromethylide, this nonequivalence arises from specific interactions with the lone electron pair of the ylide carbon atom, whose p-character is about 94% on the RHF/6–311⁺⁺G(3df,3pd) level. The alteration of the type of interaction predicts inversion of the ³⁵Cl NQR signals of the PCl₃ group in trichlorophosphonium ylide and dichloromethylide in relation to those of the CCl₃ group in the experimental spectrum of dichloro(trichloromethyl)phosphine. The MNDO-PM3 method characterizes dichloro- and diphenylmethylides as unstabilized structurally stable ylides.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 7, 2005, pp. 1148–1153.Original Russian Text Copyright © 2005 by Romanenko.     

THE SYNTHESIS OF DISODIUM O-n-ALKYLTHIOPHOSPHATES

Abstract

The disodium O-alkylthiophosphates were synthesized by reaction of PSCl₃ with the corresponding alcohols to the O-alkylphosphorodichloridothioates (1), which were hydrolyzed in aqueous triethylamin–sodium acetate solution.¹ The O-alkylthiophosphates (2) were isolated as barium salts and converted to the disodium salts by Na₂SO₄.

Because the barium salts of O-ethyl- and O-n-propyl-thiophosphate were soluble in water, the corresponding dichlorido compounds were hydrolyzed directly to the disodium salts in aqueous sodium hydroxide plus dioxane according to Gray and Hamer.²

Further purification was achieved by column chromatography on Sephadex LH20 using water as an eluant. Pure products, which were not contaminated by either inorganic thiophosphate or O-alkylphosphates, were thus obtained.     

DIPOLAR APROTIC SOLVENT EFFECTS IN THE HYDROLYSIS OF PHENYLMETHANESULFONATES AND PHENYLSULFONYLACETATES

Abstract

The hydrolytic behaviour under alkaline conditions of a group of sulfur compounds containing an active methylene group, in aqueous solvent mixtures with dimethylsulfoxide as the co-solvent has been investigated. The substrates studied are substituted phenyl phenylmethanesulfonates (A), substituted phenyl p-nitrophenylmethanesulfonates (B) and substituted phenylsulfonylacetates (C). It is known that methylenes adjacent to the sulfonyl group are acidic and evidences are available for the formation of the corresponding anions in alkaline solutions. Structure-reactivity correlations strongly suggest that these react not by the conventional addition–elimination mechanism (B_AC ²), but by an elimination-addition mechanism (ElcB) involving a slow decomposition of the corresponding anions. The rate of hydrolysis of (A) increases with increasing percentage of dimethylsulfoxide in the solvent mixtures, whereas, the reverse is the case with (B) and (C). The results are analysed on the basis of a spectrum of pathways in the ElcB mechanism, and on the basis of the relative solvation of ground and transition states of the reaction.     

ON THE REARRANGEMENT OF N-ARYL SULFIMIDES

Abstract

N-Aryl-S,S-dialkylsulfimides, 1, with R¹ = alkyl other than CH₃, have been rearranged by heating in ethanol yielding o-alkylthiomethyl-anilines, 2, as main products. Isomeric o-methylthioalkyl-anilines, 14, are formed in minor amounts only. Reactions of sulfimides, 1, with R¹ = CH₃, with certain alkylating or acylating agents yielded o-methylthiomethylated, N-alkylated or -acylated products 9. Mechanistic considerations are discussed. The rearrangement of sulfimides 1 has been assumed to occur via [2,3]-sigmatropic reactions of intermediate azasulfonium ylids 3. Attempts to resolve (+)-camphor-10-sulfonates of N-aryl sulfimides failed, but optically active N-aryl sulfimides could be obtained by reaction of anilines with optically active sulfoxides and P₄O₁₀. Optically active 2,6-disubstituted sulfimides, 1, could be rearranged in ethanolic KOH to yield optically active cyclohexadienimines 12, indicating a transfer of asymmetry from sulfur to carbon and supporting the assumption of a sigmatropic rearrangement.     

THE PHENOMENON OF CONGLOMERATE CRYSTALLIZATION. PART 53. THE CRYSTALLIZATION BEHAVIOR OF TWO COBALT(III) CARBONATO AMINE COMPOUNDS

Abstract

Two new cobalt(III) carbonato amine compounds were synthesized, and their crystal structures were determined.

Compound (I), Na₂[Co(tren)(CO₃)]₂(CIO₄)₄·3H₂O, Co₂C₁₄CI₄H₄₂N₈Na₂O 25, crystallized as a racemate in the orthorhombic system, space group Pcab (No. 61). The cell dimensions, obtained from the centering of 25 reflections, are a = 10.684(5)å, b = 18.559(8)å, c = 37.528(10)å, V= 7441(5)å³. FW= 1028.18, Z= 8, F(000) = 4203.87, dc = 1.836 Mg·m^?3, μ = 1.30 mm^?3, λ = 0.70930å. A total of 3457 data were collected over the range of 4° ≤2θ ≤40°; of these, 2377 (independent and I≥2.5σ(I)) were used in the structural analysis. The final RF and Rw residuals were 0.055 and 0.064.

Compound (II), [cis-β-Co(trien)(CO₃)](HCO₃)· H₂O, CoC₈H₂₁N₄O₇, crystallized as a conglomerate in the orthorhombic system, space group P2₁2₁2₁ (No. 19). The cell dimensions, obtained from the centering of 25 reflections, are a = 8.869(4)å, b = 12.032(8)å, c = 12.522(7)å, V = 1336(1)å³. FW = 344.20, Z = 4, F(000) = 713.62, dc = 1.701 Mg·m^?3, μ = 1.32mm^?1, λ = 0.70930å. A total of 3504 data were collected over the range of 4° ≤2θ ≤40°; of these, 2497 (independent and I≥ 2.5σ(I)) were used in the structural analysis. The final RF and Rw residuals were 0.049 and 0.059.     

Reaktionen von Jod-tris-(trifluoracetat) mit aliphatischen Jodverbindungen

The present paper deals with the behaviour of various alkyliodides towards J(OCOCF₃)₃ bearing a suitable functional group which can serve as an internal nucleophile. All the products found1–8 can be explained without any doubt by a typical neighbouring group effect with the bis-trifluoroacetoxyiodine anion, J(OCOCF₃)₂ ^–, as an easily displaced leaving group.

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F. Cech undE. Zbiral, Tetrahedron31, 605 (1975).     

REDOX AND pH-INDUCED SWITCHING OF THE COORDINATION SITES IN THE 3-HYDROXYPICOLINATE RUTHENIUM(III)-edta COMPLEX

Abstract

Ruthenium(III)-edta reacts with the 3-hydroxypicolinate ligand (Hhpic^?) at pH 5, yielding the practically colorless [Ru^III(edta)(κN, κO-Hhpic)]^2? complex (H₂hpic = 3-hydroxypicolinic acid; H₄edta = ethylenedinitrilotetraacetic acid). Above pH 9, deprotonation of the phenolic group promotes an intramolecular linkage isomerization process, generating the faint red [Ru^III(edta) (κO, κO-hpic)]^3? complex. Both isomers can be electrochemically reduced, converting into a single deep red [Ru^II(edta)(κN, κO-Hhpic)]^3? complex strongly stabilized by ruthenium-to-pyridinecarboxylate d _π → p*_π charge-transfer interactions. The observed distinct binding properties as a function of the oxidation states and pH have been rationalized based on semiempirical theoretical calculations for the complexes.     

Synthesis and in vitro cytotoxicity of platinum(II) complexes with chiral N-monosubstituted 1,2-cyclohexyldiamine derivatives as the carrier groups

Eight platinum(II) complexes with the new chiral ligands, (1R,2R)-N ¹-(pyridine-2-ylmethyl) cyclohexane-1,2-diamine (R) or (1S,2S)-N ¹-(pyridine-2-ylmethyl) cyclohexane-1,2-diamine (S) as the carrier groups were designed, synthesized, and spectrally characterized. All platinum(II) complexes showed much better aqueous solubility than cisplatin and oxaliplatin. In vitro cytotoxicity of the compounds against human HepG-2, MCF-7, A549, and HCT-116 cell lines was evaluated. Results indicate that all compounds with R as the carrier group showed cytotoxicity against HCT-116, A549, and MCF-7 cell lines; however, all compounds with S as carrier group exhibited disappointing cytotoxicity against tested cell lines. Compound R2, bearing ClCH₂COO^- as leaving group, exhibited better cytotoxicity than that of carboplatin against A549 and MCF-7 cell lines and also showed close activity to oxaliplatin against HCT-116 cell line.     

Specific Features of Chlorotropism in the ENC Triad (E = PIV-PVI,C) of High-Coordination Phosphorus Chlorides and Trichloromethyl Isocyanate

The semiempirical MNDO method and its parametrized PM3 version in supermolecular approximation was used for a comparative study of the structure and alternative mechanisms of chlorotropism in the ENC triad (E = P^{I V - V I}, C) of amidinium tetrachlorophosphorate Cl₄P(NCH₃)₂CCCl₃ (I), phosphazopentachloroethane Cl₅C₂NPO₂C₆H₄, (II), trichloromethyl isocyanate Cl₃CNCO (III), and their 1:2 chloroform solvates. The absence of the thermodynamically stable intermediate as a separated ion pair in the chlorotropic transformations of structures I, III and the high enthalpy of the substrate-intermediate transformation for structure II show that the sigmatropic mechanism of chlorotropism in compounds under study is the only probable one. The activation barrier of chlorotropism in phosphorus systems I, II is much reduced. In the case of specific solvation, a weak tendency to further reduction of the activation barrier for structures I-III is observed, and the equilibrium for phosphorus systems I, II, is appreciably shifted, unlike system III, where, according to experimental data, the equilibrium is fully to the side of the carbamoyl isomer Cl₂C = NC(O)Cl.     

THE CRYSTAL AND MOLECULAR STRUCTURE OF Ru3(CO)9(PPh3)3

Abstract

The synthesis of tertiary phosphine and phosphite substituted derivatives of M₃(CO)₁₂ {M = Ru(1a) Os(1b)} is discussed and the X-ray crystal and molecular structure of the tris-triphenylphosphine substituted ruthenium cluster Ru₃(CO)₉(PPh₃)₃ (2a) is reported. Complex 2a crystallises in the monoclinic space group P2₁/n with cell parameters a = 14.180(9), b = 21.644(14), c = 18.248(10) Å, β = 92.52(5)°, V = 5595(6) Å ³, Z = 4. The structure was solved by full-matrix least-squares methods based on F ². The refinement converged at R1 = 0.0564, wR2 = 0.2125 for 4857 observed data [F > 4σ(F)].     

Corrigendum

Three neodymium compounds, Nd(4DNP)₃(C₂H₅OH)₃ (1), Nd(4DNPO)₃ · 7H₂O (2), and {[Nd(μ-ox)(4DNPO)(H₂O)₄] · 4H₂O} _n (3) (4HDNP, 3,5-dinitropyrid-4-one; 4HDNPO, 3,5-dinitropyrid-4-one-N-hydroxide; ox, oxalate), were synthesized and characterized by FT-IR, elemental analysis, thermogravimetry–differential scanning calorimetry (TG–DSC), and two of them by single-crystal X-ray diffraction analyses. The results revealed that in 1, the Nd(III) is surrounded by three chelating ligands and three ethanol solvent molecules. The structure of 3 could be described as 1-D chains in which Nd is bis-bidentately bridged by oxalates, together with a monodentate 3,5-dinitropyrid-4-onate N-oxide 4DNPO ligand and four water molecules as well as four uncoordinated water molecules in the crystal lattice. The origin of the oxalate anions in 3 is probably due to decomposition of the 4DNPO or its oxidation of other species. The TG–DTG (DTG, derivative thermogravimetry) and DSC analyses showed that 1 underwent a three-stage decomposition process. A kinetic equation for decomposition reaction of 2 was also obtained. The apparent activation energy (E _a) and pre-exponential factor (A) of the main decomposition reaction are 157.70 kJ mol^?1 and 10^11.97 s^?1, respectively. The kinetic equation can thus be expressed as dα/dt = 10^11.97(1 ? α)e^{?1.90 × 104/ T} .     

SYNTHESIS OF THE FIRST BENZODISELENAGERMOLES AND ONE SPIROBISDISELENAGERMOLE

Abstract

The first examples of compounds R¹R²GeSe₂C₆H₄R³ (R¹,R²=CH³ C₂H₅, C₃H₂, n-C₄H₉, i-C₅H₁₁, Ph, p-CH₃Ph. R³=H, CH₃, OCH₃) were easily obtained (40–80% yield) from electrophilic cleavage of diselenophenylene zirconocenes by dialkyl or diaryl dichlorogermanes. The synthesis of a spirodi-selenagermole was achieved in the same way using germanium tetrachloride. Analytical data, ¹H and ⁷⁷Se NMR. mass spectra are perfectly consistent with the expected structures.     

EFFECT OF MAGNESIUM COMPLEXATION ON THE 31P MIDDLE-GROUP CHEMICAL SHIFTS OF CHAIN AND RING PHOSPHATES

Abstract

For pure sodium polyphosphates, Na _{n + 2}P _n O_{3n + 1}, exhibiting 3 through 6 phosphorus atoms per molecule, the ³¹P chemical shift of the middle group phosphorus atoms as measured in aqueous solution (0.1 M in P) at pH 7 was seen to increase with increasing magnesium ion concentration until there was one Mg atom per polyphosphate molecule, after which the chemical shift decreased. Finally the rate of decrease diminishes and precipitation occurs. For the longer-chain phosphates, Na _{n + 2}P _n O_{3n + 1} with n = 8, 9, 10, or an average of 100, as well as for the ring phosphates, Na _n P _n O_3n for n ranging from 3 through 10, an increase in magnesium concentration simply leads to a decrease in chemical shift which diminishes at the higher concentrations. These data lend additional support to the concept that polymerized phosphate anions in solution exist in preferred conformations which depend on the nature of the counteraction.     

Transesterification Kinetics Investigation of R‐Substituted Phenyl Benzoates with 4‐Methoxyphenol in the Presence of K2CO3 in DMF

Transesterification of R‐substituted phenyl benzoates 1–5 with 4‐methoxyphenol 6 was kinetically investigated in the presence of K₂CO₃ in dimethylformamide (DMF) at various temperatures. The Hammett plots for the reactions of the 1–5 demonstrate good linear correlations with σ⁰ constants. Low magnitude of ρ_LG values indicate that the leaving group departure occurs after the rate‐determining step. The Brønsted coefficient values for the reactions (?0.2, ?0.16, ?0.13 at 15, 24, 36°C, respectively) demonstrate the weak effect of leaving group substituent on the reactivity of R‐substituted phenyl benzoates 1–5 for the reactions with 4‐methoxyphenol 6 in the presence of K₂CO₃ in DMF. The leaving group substituent effect on free energy (ΔG^≠), enthalpy (ΔH^≠), and entropy (ΔS^≠) of activation was examined. It was shown that the activation parameters obtained depend weakly on the leaving group substituent effect. The reaction is entropy controlled in case the leaving group substituent becomes electron withdrawing.     

邻羟基苯甲酸希土配合物的合成及晶体结构

本文合成了邻羟基苯甲酸(o-HOC_6H_4CO_2H)与十五种希土的配合物,测定了铈,铽的配合物晶体结构。二者均属单斜晶系,铈配合物空间群为P2_1/n。配位数为9,铽配合物空间群为Cc,配位数为8.两种配合物均呈无限链状聚合结构。     

REACTIONS OF A PHOSPHORANIMINE ANION WITH SOME ORGANIC ELECTROPHILES

Abstract

The reactions of a variety of electrophiles with the N-silyl-P-trifluoroethoxyphosphoranimine anion Me₃Sin°P(Me)(OCH₂CF₃)CH^? ₂ (1a), prepared by the deprotonation of the dimethyl precursor Me₃SiN[dbnd]P(OCH₂CF₃)Me₂ (1) with n-BuLi in Et₂O at-78°C, were studied. Thus, treatment of 1a with alkyl halides, ethyl chloroformate, or bromine afforded the new N-silylphosphoranimine derivatives Me₃SiN[dbnd]P(Me)(OCH₂CF₃)CH₂R [2: R = Me, 3: R = CH₂Ph, 4: R = CH[sbnd]CH₂, 5: R = C(O)OEt, and 6: R = Br]. In another series, when 1a was allowed to react with various carbonyl compounds, 1,2-addition of the anion to the carbonyl group was observed. Quenching with Me₃SiCl gave the O-silylated products Me₃SiN[dbnd]P(Me)(OCH₂CF₃)CH₂°C(OSiMe₃)R¹R² [7: R ¹ = R ² = Me; 8: R ¹ = Me, R ² = Ph; 9: R¹ = Me, R ² = CH[sbnd]CH₂; and 10: R ¹ = H, R ² = Ph]. Compounds 2–10 were obtained as distillable, thermally stable liquids and were characterized by NMR spectroscopy (¹H, ¹³C, and ³¹P) and elemental analysis.     

THE 31P NMR SPECTRA OF ISOMERIC DIAMINOHEXA-CHLOROCYCLOTETRAPHOSPHAZATETRAENES; EXAMPLES OF A2B2 AND AA'BB' SPIN SYSTEMS

Abstract

The ³¹P nmr spectra of 2,4- and 2,6-diamino-derivatives of octachlorocyclotetraphosphazatetraene, N₄P₄Cl₆(NR¹R²)₂ (R¹ = H, R² = Bu^t; R¹ = H, R² = CH₂Ph; R¹ = Me, R² = Ph), have been measured. The 2,4- and 2,6-isomers were analysed as AA'BB' and A₂B₂ spin systems respectively. In the 2,4-isomers the spin-spin couplings ²J(PNP) and ⁴J(PNPNP) were of opposite sign.     

Preparation and in vitro cytotoxicity of oxaliplatin derivatives with chiral amino acid as the carrier group

Eight oxaliplatin derivatives with chiral amino acid, 2-{[(1R,2R)-2-aminocyclohexyl]amino}propanoic acid, as the carrier group, were designed, synthesized, and spectrally characterized by IR, ¹H NMR, MS spectra, and microanalyses. In vitro cytotoxicities against human HepG-2, MCF-7, A549, and HCT-116 cell lines were evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazo-liumbromide assay. Results indicated that all compounds exhibited sensitivity to HepG-2 cell line, and among them, compounds P3 and P4 which have CH₃(CH₂)₆COO^– and CH₃(CH₂)₈COO^– as the leaving groups, respectively, gave better antitumor activity than carboplatin against HepG-2 and A549 cell lines.