Alkylation Of Aniline Research Articles

Photoredox-catalyzed difunctionalization of alkenes through C[sbnd]N coupling and multicomponent radical/polar crossover

We reported an alkyl-thianthrenium salts (TTs) involved three-component radical alkene difunctionalization reaction. Alkylation of anilines has been realized via this mild method. An oxidative radical/polar crossover may be involved in the strategy, which realizing the combination of polar chemistry and radical chemistry. A variety of anilines, primary alkyl-substituted TTs, secondary alkyl-substituted TTs and olefins could be accessed in medium to good yield. Our work provides a valuable approach to producing diverse functionalized aniline derivatives.

Kinetics of Reductive Alkylation of Aniline with Acetone Using a Ni/Organoclay Catalyst

Kinetics of Reductive Alkylation of Aniline with Acetone Using a Ni/Organoclay Catalyst

Фотодеструкция полилактида с добавками терпеновых производных фенола и анилина

The article is devoted to the development of new photostabilizers of polylactide, a polymer that is an environmentally friendly alternative to fossil-based polymers. The new photostabilizers are designed to extend the life of products when exposed to ultraviolet radiation and maintain the performance of the polymer when recycled. Photostabilizers 2-isobor-nylphenol and N-para-mentenaniline were obtained while the available natural monoterpene camphene alkylation of phenol or aniline. Irradiation of polylactide samples with a photostabilizer was carried out by radiation with 253,7 nm wavelength for 4 h. The effectiveness of the photostabilizer was evaluated on the basis of IR spectrometric data, as well as by scanning electron microscopy and simultaneous thermal analysis. The introduction of each of the selected stabilizers at the concentration of 0.05% by weight resulted in the protection of ester bonds between the monomer units of the polymer. However, 2-isobornylphenol was more effective. The IR spectra analysis of the irradiated samples revealed a 15% decrease in the absorption intensity of the characteristic bands of the ester groups in the sample with 2-isobornyl-phenol, 46% in the sample with N-para-mentenaniline, and 50% in the sample without stabilizer addition. Thus, the use of 2-isobornylphenol as a photoprotective additive will extend the service life of polylactide plastic products under exposure to aggressive UV-C radiation. The protection of polylactide from UV radiation opens up prospects for expanding the areas of application of polylactide, a polymer synthesized from renewable raw materials.

Theoretical Investigation of N (p-n alkyloxy benzylidene) p-n alkyl aniline Schiff-Based Liquid Crystal Molecule

The primary objective of this article is to investigate the different physical properties of N (p-n alkyloxy benzylidene) p-n alkyl aniline liquid crystalline compound using a quantum mechanical computational method. The identified compound is used to determine the calamitic liquid crystal behavior and is classified within the nO.m family. The optimized structure of the molecule has been obtained using the DFT technique and the functional B3LYP/6-311G++(d,p) and 6-31G++(d,p) basis sets. Using this optimized structure, different reactivity, NLO, vibrational and thermodynamic parameters were calculated and analyzed. It was observed that the compound is showing a lower HOMO-LUMO energy gap value of 4.14 eV (for B3LYP/6-311G++(d,p)) and 4.11 eV (for B3LYP/6-311G++(d,p)), as a result it is easily polarizable. TD- DFT technique has been used to obtain and analyze the UV–Vis spectra. Vibrational Energy Distribution Analysis (VEDA) software was used to perform the Potential Energy Distribution (PED) function of FT-IR and Raman spectra.

Catalysis‐Controlled Selective N‐mono or N‐di‐methylation of Anilines: A Review on Synthesis of N‐methyl or N,N‐dimethyl anilines

AbstractN‐alkyl anilines are a series of common and versatile compounds which not only have been used as reaction solvents, acid‐accepters, and organic‐bases, but also in synthesis of dyes, pharmaceuticals, and anti‐colodal. The N‐methyl and/or N,N‐dimethyl anilines are the most representative ones among these. Due to their widespread uses, numerous works have been reported on synthetic strategies in the past decades. The studies on N−H methylations of anilines mainly focus on selection of reagents, selection of catalysts, or ligands design. Different transition‐metals, e. g., Ir, Ru, Pd, and et. al, with different ligands have been used in the methylation protocols. Methanol (CH3OH), carbon dioxide (CO2), formaldehyde (HCHO), or dimethyl carbonate ((CH3)2CO3) was used as C source, and hydrogen (H2) or silanes as H source. In this work, we would like to summarize the latest advances on the synthesis of N‐methyl (N,N‐dimethyl included) anilines and derivatives. This review provides an overview of reactants and catalyst, as well as an emphasis on the scope of substrates and proposed reaction mechanism for each work.

Iridium-catalyzed selective para-C-alkylation of anilines/phenols with aryl alkynes

The general protocol for site-specific alkylation of anilines and phenols would provide an ideal strategy for affording densely functionalized aniline and phenol derivatives. Herein, we disclose a new iridium-catalyzed and acid-promoted process for selective para-alkylation of anilines and phenols using aryloxy or alkoxy aryl alkynes as the alkylated sources, delivering a wide range of para-C-alkylated phenols and anilines in good to excellent yields. The low catalyst loading (up to 0.05 mol%), scale-up of synthesis, operation under air conditions, as well as recycling of catalyst (5 times without deactivation) evidenced the promising application in organic synthesis.

Using the Colloidal Method to Prepare Au Catalysts for the Alkylation of Aniline by Benzyl Alcohol.

Using the colloidal method, attempts were made to deposit Au NPs on seven different material supports (TiO2, α and γ-Al2O3, HFeO2, CeO2, C, and SiO2). The deposition between 0.8 and 1 wt% of Au NPs can be generally achieved, apart for SiO2 (no deposition) and α-alumina (0.3 wt%). The resultant sizes of the Au NPs were dependent on the nature as well as the surface area of the support. The catalytic activity and selectivity of the supported Au catalysts were then compared in the alkylation of aniline by benzyl alcohol. Correlations were made between the nature of the support, the size of the Au NP, and the H-binding energy. A minimum H-binding energy of 1100 μV K-1 was found to be necessary for high selectivity for the secondary amine. Comparisons of the TEM images of the pre- and post-reaction catalysts also revealed the extent of Au NP agglomeration under the reaction conditions.

Facile synthesis of α-tertiary alkyl/aryl amines via cu-catalyzed alkylation of indoles and anilines with tertiary alkyl bromides

Methods of copper-catalyzed alkylation of indoles and anilines with tertiary alkyl bromides were reported. These protocols provided various N-tert-alkyl 3-substituted indoles and electron-deficient N-tert-alkyl anilines in moderate to good yields via CN coupling.

A Novel Approach to α-Arylacetonitrile Skeletons via para-Selective Alkylation of Protected Anilines.

A ruthenium-catalyzed para-selective alkylation of protected anilines to construct α-arylacetonitrile skeletons has been reported. We firstly disclosed the ethyl 2-bromo-2-cyanopropanoate was an effective alkylating reagent in ruthenmuim-catalyzed remote-selective C-H functionalization. A wide variety of α-arylacetonitrile skeletons can be directly obtained with moderate to good yields. Importantly, the products contain both nitrile and ester groups guaranteeing its direct transformation into other useful synthetic units, indicating the synthetic importance of this method.

Titania Nanoparticle Catalysed N‐Alkylation of Amines by Hydrogen Auto‐Transfer Mechanisms

AbstractUnlike well‐defined homogenous metal complex catalysts, no distinct heterogeneous catalysts are available for hydrogen auto‐transfer or borrowing hydrogen methodologies. Alternatively, a variety of noble metals, base metals, and bimetallic systems supported on various metal oxides are scrutinized for this purpose, mainly by modulating the ability of metals and supports in a multistep reaction. Herein, we demonstrate that pristine defect‐induced titania nanoparticle catalyst is an efficient and recyclable heterogeneous catalyst for the preparation of N‐alkylated products (>90 %) in the absence of expensive hydrogen source, costly ligands, additives, or costly metals under greener conditions. Furthermore, the nano‐sized titania catalyst tolerates functional groups with high yields. In addition, the ‐alkylation of aniline affords the corresponding alkylated products in d yields with long aliphatic alcohols. Finally, the results of the control tests show that a process of Hydrogen Auto transfer is responsible for carrying out the reaction.

Visible-Light-Mediated Ruthenium-Catalyzed para-Selective Alkylation of Unprotected Anilines

Anilines are important moieties in organic chemistry, pharmaceuticals, and materials science. Although para-selective functionalization of anilides and tertiary anilines is well established, unprotected anilines have posed a challenge. Herein, we report visible-light-mediated Ru(II)-catalyzed para-alkylation of anilines. The distinct Ru(II)–aniline complex enabled the reaction to proceed with extremely high efficiency (2 h) under mild conditions. The good functional group tolerance allowed late-stage functionalization and even aggregation-induced emission luminogen labeling of natural products and drugs. A mechanistic investigation suggests that the Ru(II)–aniline complex is crucial for both triggering the reaction and controlling the para-selectivity.

Mechanism and Origin of Site Selectivity and Regioselectivity of Scandium-Catalyzed Benzylic C-H Alkylation of Tertiary Anilines with Alkenes.

Benzylic C(sp3)-H alkylation of tertiary anilines with alkenes by an anilido-oxazoline-ligated scandium alkyl catalyst was recently reported with C-H site selectivity and alkene-dependent regioselectivity. Revealing the mechanism and origin of selectivity is undoubtedly of great importance for understanding experimental observations and developing new reactions. Herein, density functional theory (DFT) calculations have been carried out on the model reaction of Sc-catalyzed benzylic C(sp3)-H alkylation of N,N-dimethyl-o-toluidine with allylbenzene. The reaction generally undergoes the generation of active species, alkene insertion, and protonation steps. The difference of the distortion energy of the aniline moiety in transition states, which is related to the ring size of the forming metallacycles, accounts for the site selectivity of C-H activation. Benzylic C(sp3)-H activation possessing less strained five-membered metallacycle compared to the ortho-C(sp2)-H and α-methyl C(sp3)-H activation results in benzylic C(sp3)-H alkylation observed experimentally. Both steric and electronic factors are responsible for the 1,2-insertion regioselectivity for alkyl-substituted alkenes, while electronic factors control the 2,1-insertion manner for vinylsilanes. The analysis of original alkene substrates further strengthens the understanding of the alkene-dependent regioselectivity. These results help us to obtain the mechanistic understanding and are expected to be conducive to the development of new C-H functionalization reactions.

Metal–organic framework-derived CoNx nanoparticles on N-doped carbon for selective N-alkylation of aniline

The Co–N coordination in CoNx@NC (NCN-doped carbon) was found to be beneficial in producing high conversion efficiency and high yield for secondary amines in the N-alkylation reaction between alcohol and aniline.

Ruthenium-catalysed N-alkylation of anilines with primary carbohydrate alcohols via borrowing hydrogen strategy.

Ruthenium-catalysed N-alkylation of anilines with sugar derivatives proceeded via the borrowing hydrogen strategy. Primary carbohydrate alcohols were successfully applied to N-alkylation of aniline derivatives to give the corresponding aminosugars in high yields.

Borylation directed borylation of N-alkyl anilines using iodine activated pyrazaboles

Doubly electrophilic pyrazabole derivatives (pyrazabole = [H2B(μ-C3N2H3)]2) combined with one equiv. of base effect the ortho-borylation of N-alkyl anilines.

HFIP-promoted para-selective alkylation of anilines and phenols with tertiary alkyl bromides

We have herein reported a hexafluoroisopropanol-promoted para-selective Friedel–Crafts alkylation of arenes. Preliminary mechanistic studies revealed that the intramolecular hydrogen bond network of HFIP was the key factor in realizing site-selectivity.

Alkylation of amines with allylic alcohols and deep eutectic solvents as metal-free and green promoters

A novel and green approach for the allylic alkylation of anilines, hydrazides and indole derivatives by the direct use of allylic alcohols under very mild conditions and using sustainable deep eutectic solvents (DESs) is described.

Alkylation of Aniline with Methanol over CsNaY Zeolites with Different Crystal Sizes

Alkylation of Aniline with Methanol over CsNaY Zeolites with Different Crystal Sizes

Efficient Monoalkylation of Anilines with Chalcones using Microwave-Assisted aza-Michael Addition

Abstract: The aza-Michael addition is an attractive methodology for synthetic organic chemistry because the resulting β-aminocarbonyl compounds are valuable building blocks for the synthesis of pharmaceutically useful compounds. However, monoalkylation of aniline and its derivatives is quite difficult because anilines are poor nucleophiles compared to monoalkylated ones. Since the publication of pioneering articles in 1986, the development of microwave-assisted organic synthesis has been remarkable. Therefore, we began by investigating the monoalkylation of aniline and its derivatives under microwave irradiation. Because of the ready formation of bisalkylated products, the monoalkylation reaction between anilines and Michael acceptors is quite difficult. To overcome the difficulty, we investigated the effect of microwave irradiation for the alkylation of anilines with chalcones as Michael acceptors. Microwave-assisted aza-Michael addition proceeded smoothly to obtain mainly the monoalkylated Michael adduct. The substitution effects of both chalcone and aniline concerning the yield were also studied. We supposed that dimer formation by two monoalkylated compounds produces a bulky environment around the amino group, which prevents monoalkylated compounds from undergoing a second alkylation. We confirmed a highly efficient and rapid method for preparing monoalkylated anilines using microwave-assisted aza-Michael addition between anilines and chalcones.

Half-Sandwich Iridium Complexes with Hydrazone Ligands: Synthesis and Catalytic Activity in N-Alkylation of Anilines or Nitroarenes with Alcohols via Hydrogen Autotransfer.

Here, we synthesize a series of hydrazone-based N,O-chelate half-sandwich iridium complexes through a facile route. All air-stable iridium complexes show high catalytic activity in N-alkylation of a broad scope of aniline derivatives and alcohols with liberating water as the sole byproduct. This reaction provides a smooth route to synthesize diverse monoalkylated amines in good to excellent yields at moderate temperature with a low catalyst loading. Moreover, the challenging N-alkylation process using nitroarene substrates as coupling partners is also carried out in this catalytic system. The mechanistic study shows that the present iridium catalysis process proceeds through a hydrogen borrowing mechanism. All iridium(III) complexes 1-4 are characterized by infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and elemental analysis.