Amine In Toluene Research Articles

Enhanced electrocatalytic C[sbnd]H amination of toluene via tailored interfacial microenvironment

Electrocatalytic CH amination of hydrocarbons is a promising avenue for the synthesis of high-value CN compounds. However, efficient activation of CH bonds remains a significant challenge in electrocatalytic CN coupling. Herein, we present a novel strategy to enhance the electrocatalytic conversion of toluene to N-benzylacetamide through a Ritter–type reaction by engineering a hydrophobic electrode–electrolyte interface using polytetrafluoroethylene (PTFE)-coated carbon paper (CP). The hydrophobic CP-based electrode exhibited a superior N-benzylacetamide productivity of 1860.9 mmol m−2h−1 and a substantially higher Faradaic efficiency (FE) of 70.1 % compared to pure CP (41.5 %). Experimental results and density functional theory (DFT) calculations reveal that the PTFE coating promotes toluene adsorption and efficiently lowers the energy barrier for toluene dehydrogenation. Additionally, the hydrophobic interface effectively hinders water adsorption on the electrode, suppressing the competitive water oxidation reaction. This study underscores the crucial role of interfacial engineering in optimizing electrocatalytic CN coupling reactions for the sustainable synthesis of high-value amide compounds.

Facile synthesis of N-benzylanilines via the amination of toluene over a cobalt-based catalyst

Utilizing aromatic alkanes instead of aromatic oxygenated compounds as the starting materials for efficient synthesis of N-benzylanilines remains a great challenge, which is hampered because of the chemical inertia property of aromatic alkanes. Herein, a cost-effective and promising cascade protocol was proposed for synthesis of N-benzylanilines via the amination of toluene over a cobalt-based catalyst. Both the intermediate benzalaniline and target product N-benzylanilines could be achieved in 99 % yield with the optimized conditions. Moreover, comparative experiments and characterization further clarified that the cascade synthesis of N-benzylaniline was through the amination of toluene involving oxidation, condensation, and hydrogenation reactions. Metallic cobalt loaded on Co-N-C/800-0.1 accounted for such superior catalytic performance. Furthermore, the Co-N-C/800-0.1 catalyst also showed good applicability and reusability. This study offers a potential avenue for direct synthesis of aromatic amines from available and inexpensive aromatic alkanes.

Features of Preparation of Multilayer Ultrathin Coatings from Thermosetting Epoxy Amine Systems by Spin-Coating Technique

The basic factors influencing the quality of thin films prepared by the spin-coating technique from thermosetting stoichiometric epoxy-amine mixtures have been studied. It has been shown that films 2.5–3.0 nm thick are formed on silicon supports from a 0.025 wt % solution of the stoichiometric mixture of epoxy resin and amine in toluene. Multilayer polymer coatings with thickness up to 40 nm have been prepared from successively deposited partially cured epoxy-amine layers. The thickness of these coatings grows linearly with an increase in the number of layers, while their surface energy decreases. The revealed features may be used for creating multilayer polymer coatings, the properties of which vary along the coating thickness.

Synthesize of Folic acid functionalized dendritic fibrous nano-silica and its application as an efficient nanocatalyst for access to direct amidation of carboxylic acids with amines

A new nanomaterial based on folic acid functionalized dendritic fibrous nano-silica (FA-KCC-1-NH2) was synthesized and used as a recyclable solid acid and heterogeneous nanocatalyst towards efficient amidation of a variety of carboxylic acids with amines in toluene under reflux conditions. KCC-1 porous nanomaterials were produced utilizing a hydrothermal technique and in the next functionalized with folic acid moieties to yield KCC-1-NH-FA nanocatalyst. The structure of KCC-1, KCC-1-NH2 and KCC-1-NH-FA nanoparticles were investigated by FESEM, DLS, zeta potential and TEM, instrumental techniques. Also, the pore size of KCC-1-NH-FA nanoparticles were moreover investigated with BET where results revealed that the surface of this nanocomposite was expanded. The synthesized KCC-1-NH-FA nanoparticles showed effective catalytic activity in amidation of carboxylic acids with amines affording in high yields (76-89%) and short period of times. Moreover, other advantages of present method are easy workup, no need to use of chromatographic column and excellent recyclability of catalyst without significant loss in its catalytic activity which gives economic rewards.

Ring Opening of 4-Arylamino-2-tert-butyl-5-oxo-2,5-dihydrofuran-2-yl Acetates with Aromatic and Heterocyclic Amines

Reactions of 4-arylamino-2-tert-butyl-5-oxo-2,5-dihydrofuran-2-yl acetates with an equimolar amount of aromatic or heterocyclic amine in toluene involves initial attack of the amine on the C2 atom of the furan ring, followed by opening of the furan ring and elimination of acetic acid to give N-aryl(hetaryl)-2-arylamino-5,5-dimethyl-4-oxohex-2-enamides.

Fiber-polyquaterniums@Cu(I) as recyclable polymer-supported copper complex catalysts for alkyne coupling and cycloaddition reactions

Herein, a newly designed and synthesized fiber-supported polyquaterniums@Cu(I) served as efficient and recyclable polymer-supported copper complex catalysts for alkyne coupling and cycloaddition reactions, is reported. The fiber-supported copper complex catalyst was prepared systematically from commercially available polyacrylonitrile fiber, and characterized detailedly by elemental analysis, FTIR spectroscopy, mechanical properties, and SEM during both of the preparation and utilization processes. Moreover, the fiber-supported polyquaterniums@Cu(I) has been verified to possess high catalytic activities for the homocoupling of terminal alkyne in ethyl acetate (10 samples yields 83–99%, 10 cycles from 98% to 95%), A3 coupling of alkyne, aldehyde and amine in toluene (10 samples yields 81–94%, 10 cycles from 94% to 90%), and click chemistry of CuAAC reactions in water (10 samples yields 82–99%, 21 cycles from 97% to 96%). Furthermore, the newly developed fiber catalyst in spinning basket reactor displayed excellent stability and recyclability, and the concise and effective gram-scalable operation has extensive application prospect on chemical productions.

High-Spin Iron Imido Complexes Competent for C-H Bond Amination.

Reduction of previously reported (ArL)FeCl with potassium graphite furnished a low-spin (S = 1/2) iron complex (ArL)Fe which features an intramolecular η6-arene interaction and can be utilized as an FeI synthon (ArL = 5-mesityl-1,9-(2,4,6-Ph3C6H2)dipyrrin). Treatment of (ArL)Fe with adamantyl azide or mesityl azide led to the formation of the high-spin (S = 5/2), three-coordinate imidos (ArL)Fe(NAd) and (ArL)Fe(NMes), respectively, as determined by EPR, zero-field 57Fe Mössbauer, magnetometry, and single crystal X-ray diffraction. The high-spin iron imidos are reactive with a variety of substrates: (ArL)Fe(NAd) reacts with azide yielding a ferrous tetrazido (ArL)Fe(κ2-N4Ad2), undergoes intermolecular nitrene transfer to phosphine, abstracts H atoms from weak C-H bonds (1,4-cyclohexadiene, 2,4,6-tBu3C6H2OH) to afford ferrous amido product (ArL)Fe(NHAd), and can mediate intermolecular C-H amination of toluene [PhCH3/PhCD3 kH/kD: 15.5(3); PhCH2D kH/kD: 11(1)]. The C-H bond functionalization reactivity is rationalized from a two-step mechanism wherein each step occurs via maximal energy and orbital overlap between the imido fragment and the C-H bond containing substrate.

Expedient synthesis of novel coumarin-based sulfonamides

The synthesis of novel coumarin-based sulfonamides was accomplished in good yields via InCl3-catalyzed three-component condensation of N-(2-formylphenyl)-N-methylbenzenesulfonamides, 4-hydroxycoumarin and cyclic secondary amines in toluene.

A new synthetic route for the preparation of metal tellurides

A new method of synthesis for the formation of metal tellurides of the type MTe (M=Cd, Hg) is reported. The compounds were prepared by the reaction of cadmium carbonate (or mercury oxide, respectively) with tellurium and bis(diphenylphosphino)amine in toluene at 160°C. The products were characterized by powder XRD and EDX analyses. The whole chemical process is discussed.

Activation of Carbodiimide and Transformation with Amine to Guanidinate Group by Ln(OAr)3(THF)2 (Ln: Lanthanide and Yttrium) and Ln(OAr)3(THF)2 as a Novel Precatalyst for Addition of Amines to Carbodiimides: Influence of Aryloxide Group

Reaction of Ln(OAr(1))(3)(THF)(2) (Ar(1)= [2,6-((t)Bu)(2)-4-MeC(6)H(2)] with carbodiimides (RNCNR) in toluene afforded the RNCNR coordinated complexes (Ar(1)O)(3)Ln(NCNR) (R = (i)Pr (isopropyl), Ln = Y (1) and Yb (2); R = Cy (cyclohexyl), Ln = Y (3)) in high yields. Treatment of 1 and 2 with 4-chloroaniline, respectively, at a molar ratio of 1:1 yielded the corresponding monoguanidinate complex (Ar(1)O)(2)Y[(4-Cl-C(6)H(4)N)C(NH(i)Pr)N(i)Pr](THF) (4) and (Ar(1)O)(2)Yb[(4-Cl-C(6)H(4)N)C(NH(i)Pr)N(i)Pr](THF) (5). Complexes 4 and 5 can be prepared by the reaction of Ln(OAr(1))(3)(THF)(2) with RNCNR and amine in toluene at a 1:1:1 molar ratio in high yield directly. A remarkable influence of the aryloxide ligand on this transformation was observed. The similar transformation using the less bulky yttrium complexes Y(OAr(2))(3)(THF)(2) (Ar(2) = [2,6-((i)Pr)(2)C(6)H(3)]) or Y(OAr(3))(3)(THF)(2) (Ar(3) = [2,6-Me(2)C(6)H(3)]) did not occur. Complexes Ln(OAr(1))(3)(THF)(2) were found to be the novel precatalysts for addition of RNCNR with amines, which represents the first example of catalytic guanylation by the lanthanide complexes with the Ln-O active group. The catalytic activity of Y(OAr(1))(3)(THF)(2) was found to be the same as that of monoguanidinate complex 4, indicating 4 is one of the active intermediates in the present process. The other intermediate, amide complex (Ar(1)O)(2)Ln[(2-OCH(3)-C(6)H(4)NH)(2-OCH(3)-C(6)H(4)NH(2))] (6), was isolated by protonolysis of 4 with 2-OCH(3)-C(6)H(4)NH(2). All the complexes were structurally characterized by X-ray single crystal determination.

A Benzannulation Protocol To Prepare Substituted Aryl Amines Using a Michael-Aldol Reaction of β-Keto Sulfones

A practical benzannulation method to prepare variously substituted aryl amines and sulfides was developed. The approach involves a Michael-aldol reaction of beta-keto sulfones with enones followed by a subsequent condensation of the initial adduct with various amines. The base-induced Michael-aldol cascade proceeds smoothly with a number of different beta-keto sulfones, affording the adducts as single diastereomers. Heating the resulting Michael-aldol product with an amine in toluene at 120 degrees C results in the formation of a transient enamine, which then undergoes loss of phenyl sulfenic acid to furnish the aromatized amine in good yield. A related reaction also occurred when the Michael-aldol product was heated with thiols or alcohols, giving rise to aryl-substituted sulfides or ethers.

Kinetics of SNAr reactions of 1‐phenoxy‐nitrobenzenes with aliphatic amines in toluene: ring substituent and solvent effects on reaction pathways

AbstractRate constants are reported for the reactions of a series of 4‐substituted‐1‐phenoxy‐2,6‐dinitrobenzenes 1 and 6‐substituted‐1‐phenoxy‐2,4‐dinitrobenzenes 2 activated by CF3, COOCH3, CN, NO2 groups or by ring‐nitrogen with n‐butylamine, pyrrolidine or piperidine in toluene. The results are compared with those reported previously for reactions of the same substrates and nucleophiles in acetonitrile [Crampton et al., Eur. J. Org. Chem., 2006, 1222–1230]. Plots of the overall second‐order rate constant, kA versus [Am] for the reactions with n‐butylamine and pyrrolidine followed a similar kinetic pattern to that obtained for the same reactions in acetonitrile whereas for reactions with piperidine, an upward (convex) curvature is observed, an indication that a small third order term in amine may be present. Overall reactivity is lower in toluene than in acetonitrile. Mechanisms for the overall substitution process have been rationalised in terms of the proton transfer mechanism and cyclic transition mechanism, for reactions involving third‐order kinetics. Copyright © 2009 John Wiley & Sons, Ltd.

Synthesis, properties and crystal structures of volatile β-ketoiminate Pd complexes, precursors for palladium chemical vapor deposition

The β-aminovinylketone ligands CH 3C(NH 2)CHC(O)CH 3 ( 1) and CH 3C(NHCH 3)CHC(O)CH 3 ( 2) were synthesized from 2,4-pentandione by amination with a water solution of the appropriate amine in toluene at room temperature. The reactions of 1 and 2 with the PdCl 2 salt in amine medium gave the volatile chelate metal complexes Pd[CH 3C(NH)CHC(O)CH 3] 2 ( 3) and Pd[CH 3C(NCH 3)CHC(O)CH 3] 2 ( 4). The obtained compounds were identified by elemental analysis, 1H and 13С NMR, IR-spectroscopy and were characterized by TGA and a single-crystal X-ray diffraction study. In compounds 3 and 4, the Pd atom has a square coordination environment Pd O 2N 2.

Unusual p‐Toluene Sulfonic Acid—Catalyzed Carbon—Carbon Bond Formation.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Unusual p‐Toluene Sulfonic Acid–Catalyzed Carbon–Carbon Bond Formation

Attempts to synthesize the antidepressant drug atomoxetine directly by p-TSA‐catalyzed reaction between o‐cresol and N‐methyl‐3‐phenyl‐3‐hydroxypropyl amine in toluene at reflux temperature surprisingly resulted in the formation of ortho‐substituted phenol derivative. The structure is unambiguously confirmed by single crystal X-ray.

Experimental and Theoretical Studies of Fused-Ring Persistent [1,2,4]Thiadiazinyl Radicals

Five persistent radicals 1a-1e were generated by the oxidation of 4H-[1,2,4]thiadiazines 2a-2e and studied with ESR and UV-vis spectroscopy. Three of the radicals, 1a, 1d, and 1e, were generated in high yields (>90%) using either SO(2)Cl(2)/amine in toluene or AgO/K(2)CO(3) in a toluene/MeCN mixture. Halogenated radicals 1d and 1e were sufficiently stable for chromatographic isolation and vacuum sublimation. The solution stability of the fluorinated 1d was measured at t(1/2) approximately 4 months in the absence of oxygen, and 1e at t(1/2) approximately 40 min in the presence of air. The crystal and molecular structures of 1d were determined by X-ray crystallography showing columns of parallel almost evenly spaced planar heterocycles connected by infinite ...N...S... chains. Cyclic voltammetry of 1d and 1e shows reversible reduction waves at about 0 V and irreversible oxidations at about 1.2 V. Spectral and electrochemical properties of 1 were well reproduced by DFT methods.

Synthesis, spectral characterization and crystal structures of organophosphonic diamides: pyramidal nitrogen centers and hydrogen bonding in [PhP(O)(NHtBu)2], [PhP(O)(NHDipp)2] (Dipp = 2,6-iPr2C6H3) and [tBuP(O)(NHiPr)2

Organophosphonic diamides of general formula [R1P(O)(NHR2)2] (1–8; R1 = Ph, Cy or tBu and R2 = Cy, iPr, tBu or Dipp) have been prepared by the addition of P,P'-dichloro(alkyl/aryl)phosphine oxide, R1P(O)Cl2, to a solution of primary amine in toluene. The synthesis of PhP(O)(NHtBu)2 (1) in high yield was achieved by slow oxidation of PhP(NHtBu)2 in air over several days. All new compounds have been characterized by elemental analysis and by IR, EI mass and NMR (1H and 31P) spectroscopy. The molecular structures of [PhP(O)(NHtBu)2] (1), [PhPO(NHDipp)2] (2) and [tBuP(O)(NHiPr)2] (7) have been determined by single crystal X-ray diffraction studies. The amido nitrogen atoms in 1, 2 and 7 show considerable deviation from the expected trigonal-planar geometry. The observed dihedral angles and the orientation of the nitrogen lone pair (l.p.) in these compounds point to the role of l.p.(N) → σ*(P–X) type negative hyperconjugative interactions in P–N multiple bonding. Compounds 1 and 7 form interesting polymeric structures in the solid state with the aid of N–H⋯OP hydrogen bonding interactions while the presence of the very bulky Dipp substituent on nitrogen in 2 prevents the participation of the N–H protons in hydrogen bonding with phosphoryl oxygen atoms.

Synthesis of some novel quinoline-3-carboxylic acids and pyrimidoquinoline derivatives as potential antimicrobial agents.

The synthesis and in vitro antimicrobial evaluation of several quinoline and pyrimidoquinoline derivatives are described. Treatment of 7-substituted quinolin-2(1H)-one-3-carboxylic acids 2a-c with phosphoryl chloride or thionyl chloride gave rise to the 7-substituted 2-chloroquinoline-3-carboxylic acids 3a-c and 7-substituted 2-chloro-3-chlorocarbonylquinolines 5a-c respectively. The 2-chloro function in compounds 3a-c was replaced by 2-aminothiazole or 2-aminopyridine to give 2-(thiazol-2-yl)aminoquinoline-3-carboxylic acids 4a-c or 2-(pyrid-2-yl)aminoquinoline-3-carboxylic acids 4d-f. Treatment of 5a-c with the same heterocyclic amines at room temperature furnished the corresponding 7-substituted 2-chloro-3-heteryl-aminocarbonylquinolines 6a-f. The tetracyclic 9-substituted thiazolo[3', 2':1, 2]-pyrimido[4, 5-b]quinolin-5-ones 7a-c and 10-substituted pyrido[1', 2':1, 2]-pyrimido[4, 5-b]quinolin-6-ones 7d-f were synthesized by heating 5a-c with the heterocyclic amines in toluene or by heating 6a-f under reflux in dimethylformamide. The products were evaluated in vitro for potential antimicrobial activity.

A comparison of the extraction of carrier-free176,177W and99Mo with that of U, Th, Am, Cm, La, Ce, Tm, Yb, Lu, and Hf into tri-n-octyl amine in toluene from nitric, phosphoric, and sulphuric acid media

The extraction of carrier-free tungsten and molybdenum from nitric, phosphoric and sulphuric acid with 0.05 M TOA (tri-n-octyl amine, R3N) in toluene and 2.5% by volume 1-dodecanol has been studied. Their extraction behaviour has also been compared to hafnium, some trivalent lanthanides (lanthanum, cerium, thulium, ytterbium and lutetium) and some actinides (thorium, uranium, americium and curium). The extraction of these metal ions decreases in the order M4+>MO22+>M3+from >1 M nitric acid solutions, if hafnium, which is on the form HfO2+, is disregarded. At low nitric acid concentrations tungsten and molybdenum are most likely extracted as tungstate or molybdate ions (R3NH)2·MO4, while at higher concentrations they are most likely extracted similar to uranium, i.e. on the form R3NH·MO2(NO3)3. Further, the extraction from phosphoric acid solutions decreases in the order M4+>MO22+>M3+, if the elements which are easily hydrolysed, hafnium, molybdenum and tungsten, are disregarded. The major extracted complex of tungsten contains one TOA and the minor two TOA. The extracted complex with one TOA is probably (R3NH)·WO2(H2PO4)3or R3N·WO2(H2PO4)2, while that with two TOA more likely is (R3N)2H·WO2(H2PO4)3or even the more hydrolysed species of tungsten (R3NH)2·WO4. For molybdenum, the extracted complexes seem reasonably similar. Disregarding HfO2+the extraction decreases in the order MO22+>M4+>M3+for the chosen range of sulphuric acid concentration.

An original traceless linker strategy for solid-phase synthesis of N,N',N''-substituted guanidines.

An original sequence for solution- and solid-phase synthesis of N,N',N"-trisubstituted guanidines is described. The sequence involves as key intermediate a bis-electrophilic chlorothioformamidine that is stable, easy to prepare and also easy to handle. Supported chlorothioformamidine, prepared in two steps from Merrifield resin, undergoes smooth nucleophilic addition of a primary amine to afford the corresponding supported isothiourea. The guanidine is obtained in satisfactory yield and good purity through a functionalizing-release process by heating the supported isothiourea in the presence of a primary amine in toluene at 100 degrees C. Compatibility of this sequence with several functional groups is demonstrated.