Triethylamine In Toluene Research Articles

Synthesis of Mesylated and Tosylated α-Hydroxy-Benzylphosphonates; Their Reactivity and Cytostatic Activity.

α-Hydroxyphosphonates and their acylated and phosphorylated derivatives may be of significant biological activity including cytotoxic effects. To extend the pool of the potentially bioactive species, new methane- and arenesulfonyloxyphosphonates were synthesized by the sulfonylation of differently substituted α-hydroxy-benzylphosphonates using methanesulfonyl chloride or p-toluenesulfonyl chloride at 25 °C in the presence of triethylamine in toluene. The new sulfonyl derivatives were obtained in 54-80% yields. In the case of the 4- or 2-methoxy substituent in the aromatic ring, surprisingly the corresponding α-chlorophosphonates were the exclusive products, whose formation was explained assuming a quinoid intermediate and supported by theoretical calculations. With a 3-methoxyphenyl substituent, the expected mesylation of the hydroxy group took place. Attempted alcoholyses of the diethyl α-methanesulfonyloxy-benzylphosphonates with different substituents in the benzyl ring at ∼140 °C in the presence of triethylamine under microwave irradiation left the P-function intact under the conditions applied, instead, the mesyloxy group was substituted by an alkoxy unit in a selective new reaction. The α-alkoxy-benzylphosphonates were isolated in 60-77% yields. While α-chloro- or α-bromo-benzylphosphonates proved to be rather inefficient in the Michaelis-Arbuzov reaction with triethyl phosphite, according to a new possibility, the α-methansulfonyloxy-benzylphosphonates underwent an efficient Arbuzov fission using the phosphite in excess at 135 °C. The arylmethylenebisphosphonates were obtained in yields of 76-81%. Bioactivity studies with the members of the phosphonate library revealed pronounced in vitro cytostatic effect of the α-hydroxy- and α-mesyloxy-3,5-di-tert-butylbenzylphosphonates on human breast carcinoma cell culture with IC50 values of 16.4 and 28.0 μM, respectively. The mesyloxy species was also cytostatic on melanoma cells (IC50 = 34.9).

4,7-(bis(octyloxy)-3-(quinoline-2-ylmethylene)isoindoline-1-one and its boronflouride complex. synthesis and spectral-luminescent properties

4,7-Bis(octyloxy)isoindoline-1,3-dione was obtained by reacting 3,6-bis(octyloxy)phthalonitrile with sodium butoxide in butanol, followed by treatment with hydrochloric acid. Its condensation with quinaldine in the presence of zinc oxide leads to the formation of ( E , Z )-4,7-bis(octyloxy)-3-(quinolin-2-ylmethylene)isoindolin-1-one, which was treated with BF3۰Et2O in the presence of triethylamine in toluene to give a new unsymmetrical analogue of BODIPY - ( Z )-2-(difluoroboryl)-4,7-bis(octyloxy)-3-(quinolin-2-ylmethylene)isoindolin-1-one. The complex exhibits a Stokes shift of 25 nm and a high relative fluorescence quantum yield (0.68). To support the experimental data, DFT and TD-DFT calculations were performed.

Synthesis of N-substituted-4-methylene-oxazolidinones via base-catalyzed cyclization of propargylic alcohols with p-toluenesulfonyl isocyanate

A practical method is developed for the synthesis of oxazolidinone derivatives, an important class of heterocyclic compounds. The effect of bases and solvents on this cyclization reaction is discussed and a simple new base–solvent system (triethylamine in toluene) is found to be the most effective. The reaction conditions developed here are mild and no by-products are observed. Moreover, using optimized conditions, a number of differently substituted propargylic alcohols are cyclized to the corresponding N-substituted-4-methylene-oxazolidinones in yields of up to 99%.

Synthesis, crystal structure and photoluminescence of [NHEt3][Re(I)(quinaldate)(CO)3Cl

Abstract The salt [NHEt3][Re(I)(quinaldate)(CO)3Cl] was obtained by the reaction of Re(CO)5Cl with quinaldic acid and triethylamine in toluene. The crystal structure analysis of this salt revealed the presence of the complex anion [Re(quinaldate)(CO)3Cl]−, with the d 6 Re(I) metal center in a pseudo-octahedral environment. The electronic spectra in absorption and emission exhibit bands which are attributed to quinaldate IL and CT transitions at comparable energies. The longest-wavelength emission originates from a Re(I) to quinaldate MLCT triplet, which can be quenched in solution by oxygen or triethylamine.

Lithium Hexamethyldisilazide-Mediated Enolization of Highly Substituted Aryl Ketones: Structural and Mechanistic Basis of the E/Z Selectivities.

Enolizations of highly substituted acyclic ketones used in the syntheses of tetrasubstituted olefin-based anticancer agents are described. Lithium hexamethyldisilazide (LiHMDS)-mediated enolizations are moderately Z-selective in neat tetrahydrofuran (THF) and E-selective in 2.0 M THF/hexane. The results of NMR spectroscopy show the resulting enolates to be statistically distributed ensembles of E,E-, E,Z-, and Z,Z-enolate dimers with subunits that reflect the selectivities. The results of rate studies trace the preference for E and Z isomers to tetrasolvated- and pentasolvated-monomer-based transition structures, respectively. Enolization using LiHMDS in N,N-dimethylethylamine or triethylamine in toluene affords a 65:1 mixture of LiHMDS-lithium enolate mixed dimers containing E and Z isomers, respectively. Spectroscopic studies show that condition-dependent complexation of ketone to LiHMDS occurs in trialkylamine/toluene. Rate data attribute the high selectivity exclusively to monosolvated-dimer-based transition structures.

Synthesis and solid state structures of Chalcogenide compounds of Imidazolin-2-ylidene-1,1-Diphenyl-phosphinamine

We report the synthesis and solid state structures of 1,3-di-aryl-imidazolin-2-ylidine-1,1-diphenylphosphinamine [(aryl = mesityl (1a) and aryl = 2,6-diisopripyl (1b)] and their chalcogenide compounds 1, 3-di-aryl-imidazolin-2-ylidine- P,P-diphenylphosphinicamide (2a,b), 1,3-di-aryl-imidazolin-2-ylidine-P,P-diphenyl-phosphinothioicamide (3a,b) and 1,3-diaryl-imidazolin-2-ylidine- P,P-diphenyl-phosphinoselenoic-amide (4a,b). The compounds 1a,b were prepared in good yield by the reaction of 1,3-di-aryl-imidazolin-2-imine and chlorodiphenylphosphine in the presence of triethylamine in toluene. The reactions of 1a,b with elemental sulphur and selenium afforded the corresponding chalcogenide compounds 3a,b and 4a,b respectively. The corresponding oxo- derivative (2a,b) was obtained by reacting compound 1a,b with 30% aqueous hydrogen peroxide in THF. The molecular structures of 1a, 2a, 3a and 4a,b have been established by single crystal X-ray diffraction analyses. The molecular structures reveal that even C1–N1–P1 angle (124.62 ∘) in compound 1a is less obtuse compared to the corresponding C1–N1–Si1 angles (157.8 ∘) observed in related N-silylated 2-iminoimidazolines and trimethylsilyl iminophosphoranes. C1–N1–P1 angles are further widened in compounds 2a, 3a, and 4a,b due to the attachment of chalcogen atoms onto phosphorus atom.

ChemInform Abstract: Bromotriphenylphosphonium Salt Promoted One‐Pot Cyclization to 2‐Fluoroalkyl‐Substituted Indoles.

2-Fluoroalkyl-substituted indoles were prepared in moderate to excellent yields through bromotriphenylphosphonium salt promoted ring formation with fluorine-containing carboxylic acids in the presence of triethylamine in toluene at reflux temperature. A range of 2-fluoroalkyl-substituted indole derivatives can be conveniently prepared.

The cyclopentyl group, as a small but bulky terminal group, allows rapid and efficient active transport.

Secondary ammonium salts bearing a cyclopentyl terminal group rapidly formed pseudorotaxane with 1.5 equiv of DB24C8. Acylation of the pseudorotaxane with 50 equiv of benzoyl chloride in the presence of 50 equiv of triethylamine in toluene afforded rotaxane, the product of active transport, in 95% yield. The cyclopentyl group is small enough to allow rapid formation of pseudorotaxane, and bulky enough to facilitate the quantitative active transport by steric repulsion.

Bromotriphenylphosphonium Salt Promoted One-Pot Cyclization to 2-Fluoroalkyl-Substituted Indoles

2-Fluoroalkyl-substituted indoles were prepared in moderate to excellent yields through bromotriphenylphosphonium salt promoted ring formation with fluorine-containing carboxylic acids in the presence of triethylamine in toluene at reflux temperature. A range of 2-fluoroalkyl-substituted indole derivatives can be conveniently prepared.

Synthesis and X-ray structure of ruthenium bis(acetylacetonate)(N,N,N′,N′-tetramethylethylenediamine)

Although several ruthenium complexes of the type Ru(acac)(2)(L)(x), where x is 1 for a bidentate or 2 for a monodentate ligand, are known, the tmed complex is conspicuously absent. This article describes the synthesis of this complex from trans-RuCl(2)(tmed)(2), acetylacetone, and triethylamine in toluene. A new synthesis of trans-RuCl(2)(tmed)(2) is also described. Some physical properties and the X-ray crystal structure of Ru(acac)(2)(tmed) are provided.

New method for the synthesis of benzene- and phenylmethanesulfonylmethyl-substituted 1,3-dithiolanes and 1,3-dithianes

The reactions of (E)-chlorovinyl sulfones with 1,2-ethanedithiol or 1,3-propanedithiol in the presence of triethylamine in toluene at 80°C lead to the selective formation of 1,3-dithiolane and 1,3-dithiane derivatives with yields of up to 49%.

Structural Consequences in α‐ and β‐Glucopyranosidato Complexes of Cp*TiCl3

AbstractThe reaction of methyl‐4,6‐O‐(naphthyl‐2′‐methylidene)‐α‐D‐glucopyranoside (α‐MeNGH2) with trichloridopentamethylcyclopentadienyltitanium [Cp*TiCl3] and triethylamine in toluene reveals the dinuclear complex [(Cp*TiCl)‐μ‐(α‐MeNG)]2 (2). Complex 2 was characterized by elemental analysis, 1H and 13C NMR spectroscopy, circular dichroism, as well as single‐crystal structure analysis. Compared to the complex with the β‐anomer of the ligand in [(Cp*TiCl)‐μ‐(β‐MeNG)]2 (1), it is obvious that the absolute configuration of the Ti atoms in 2 have changed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Solid-Phase Synthesis of Amines via the Curtius Rearrangement

Solid-phase synthesis of aryl, ­heteroaryl and sterically hindered alkyl amines using the Curtius rearrangement was described. Thus, Wang resin 1 reacted with carboxylic acids (3 mol equiv to OH residue of the resin), DPPA, and triethylamine in toluene to give the corresponding carbamate-anchored resins 2. Treatment of 2 with 50% TFA in dichloromethane ­afforded the amines 3 in 60 to >95% yield (19 ­examples).

The Formation of Spiro-β-lactams and Amides from Reaction of Cyclic Ketenes with Imines

Spiro-β-lactams are interesting compounds due to their antiviral, and antibacterial properties, ability to inhibit cholesterol absorption, and the enzymes responsible for the cleavage of the amyloid precursor protein. Most synthetic efforts to form spiro-β-lactams utilize cycloaddition reactions. The cycloaddition usually uses ketene-imine. In this paper, we present a novel synthesis of spiro-βlactam derivatives 3 and amide derivatives 4, from cyclic acid chloride 1 with imine 2 (Scheme 1). We will describe the effects which govern selectivity in the formation of 3 and 4, and show that the size of the ring in 1 has the largest influence in this process. The spiro-β-lactams 6 and 8 were prepared by reaction of either cycloheptyl acid chloride 5 or cyclohexyl acid chloride 7 with imine 2, respectively (Scheme 2). In a typical procedure, the acid chloride was added to a stirred, refluxing solution of the imine and triethylamine in toluene. After refluxing the solution overnight and an aqueous work-up, spiro-β-lactams 6 and 8 were obtained in moderate yields and trash amount of side products were detected in TLC. The spiro-β-lactams 6 and 8 are the expected products of the [2+2] cycloadition reaction of imine 2 with the cyclic ketenes intermediate. We next examined the formation of spiro-β-lactams 10, from the reaction of cyclopentyl acid chloride 9 and imine 2. Under the same reaction conditions described above, spiroβ-lactams 10 was obtained in 55% yield and small amount of side products were observed in TLC. On the other hand, the amide 11 was obtained when the reaction was performed

Facile One‐Pot Syntheses of Amidines and Enamines from Oximes via Beckmann Rearrangement Using Trifluoromethanesulfonic Anhydride.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Facile One-Pot Syntheses of Amidines and Enamines from Oximes via Beckmann Rearrangement Using Trifluoromethanesulfonic Anhydride

Abstract Iminocarbocation intermediates were in situ-generated by treating various oximes with trifluoromethanesulfonic anhydride (Tf2O) in the presence of triethylamine in toluene and nucleophilic trapping with amines or sodium enolates under mild conditions afforded the corresponding amidines and enamines. Some of the thus-obtained enamines were converted to 2-substituted 4-oxo-3-quinolinecarboxylic acid derivatives by subsequent intramolecular Friedel–Crafts acylation.

Syntheses and Structures of Trilithium Cyclotriphosphazenates Equipped with 2‐Halo‐aryl Substituents

AbstractHexakis (2‐halo‐anilino) cyclotriphosphazenes (2‐X‐C6H4NH)6P3N3 {X = F (1d), Cl (1e), Br (1f)} were prepared by refluxing mixtures of hexachloro cyclotriphosphazene, 2‐haloaniline and triethylamine in toluene and characterized by single crystal X‐ray diffraction. 1d, 1e and 1f were reacted with nBuLi in thf. Reactions were monitored with 31P NMR. Addition of three equivalents of nBuLi yields lithium complexes of trianionic phosphazenates [{(thf)2Li}3{(2‐X‐C6H4N)3(2‐X‐C6H4NH)3P3N3}] {X= F (2d), Cl (2e) and Br (2f)}. 2d, 2e and 2f were structurally characterized by X‐ray diffraction, which reveals monomeric cis‐metalated phosphazenates featuring central P3N3 ring systems of chair conformation. Lithium ions reside in three N(eq)‐P‐N(endo) chelation sites at one face of the P3N3 ring system. Li…X distances are rather long (> 3Å) indicating no Li‐X interactions.

A Novel Method for the Coupling of Nucleoside Bases with Tetramethylene Sulphoxide

A silicon mediated Pummerer reaction for the coupling of nucleoside bases to a tetrahydrothiophene ring is described. Thus, treatment of the required base with TMS-triflate and triethylamine in toluene followed by the addition of tetramethylene sulphoxide and catalytic ZnI2 gave the requisite coupled product in moderate to good yield.

Cyclization of Substituted Phenyl N-(2-Hydroxybenzyl)carbamates in Aprotic Solvents. Synthesis of 4H-1,3-Benzoxazin-2(3H)-ones

The kinetics of cyclization of substituted phenyl N-(2-hydroxybenzyl)carbamates and their N-methyl analogs, prepared by the reaction of 2-(aminomethyl)phenols with substituted phenyl chloroformates, was studied in dioxane or toluene at the temperatures 110-180 °C. Electron-withdrawing substituents in the leaving phenoxy group strongly accelerate the rate of cyclization (ρ = 2.45 ± 0.15) while the substituents in the other ring have virtually no effect. The cyclization was catalyzed with triethylamine in toluene but not in dioxane. On the basis of these results, the most convenient method for preparation of substituted 4H-1,3-benzoxazin-2(3H)-ones was a one-hour reflux of substituted 4-nitrophenyl N-(2-hydroxybenzyl)carbamates in dioxane. Based on the influence of substituents, solvents (dioxane and toluene) and triethylamine, the reaction mechanism and structure of the transition state were proposed.

Synthesis and characterization of novel polyaryloxydiphenylsilane derived from 2,2?- dimethyl-biphenyl-4,4?-diol

A novel polyaryloxydiphenylsilane was synthesized successfully by solution polycondensation of 2,2′-dimethyl-biphenyl-4,4′-diol with diphenyldichlorosilane and the catalyst triethylamine in toluene at 80 °C. Polymers with a relatively high inherent viscosity and yield were obtained when the reactions were carried out in aromatic and lipophilic solvents. The novel polyaryloxydiphenylsilane was soluble in chlorinated aliphatic hydrocarbons such as methylene chloride and chloroform as well as in polar solvents such as dimethyl sulfoxide, N,N-dimethylformamide, and N,N-dimethylacetamide and also in some common organic solvents such as benzene and toluene. However, it was insoluble in both aliphatic hydrocarbons as well as in alcoholic solvents. The polyaryloxydiphenylsilane began losing weight around 400 °C under a nitrogen atmosphere, and the 10% weight-loss temperature was 473 °C. The glass-transition temperature of the polyaryloxydiphenylsilane was 102 °C. The glass transition could be lowered by the copolymerization technique with 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane as an aromatic diol comonomer. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 4591–4595, 1999