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Other nitrogen sources. Reaction conditions were as follows: aroyl chloride 1 (0.2 mmol), LiHMDS (2.5 equiv.), aDCE (3 mL) and bdioxane (3 mL), RT, <5 min
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Herein, we report a solvent-controlled highly selective amidation and imidation of aroyl chlorides using an alkali-metal silyl-amide reagent (LiHMDS), which serves as a nitrogen source at room temperature. A unique feature of this method lies in the sequential silyl amidation of aryol chlorides and nitrogen-silicon bond cleavage of the correspondin...
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This study includes synthesis of some benzothiazole derivatives from treatment 2 -aminothiazole with choroacyle chloride to form 1-hydrogen-benzothiazole-2yl-2-chloroastiamide (1).the last one was reacted with urea, thiurea, thiosymigarizaide, 2- amibenzothiazole and para- aminoaniline, respectively to form the compounds (2,6). Some shiff bases for...
Citations
Solvent plays an important role in many chemical reactions. The C−H activation has been one of the most powerful tools in organic synthesis. These reactions are often assisted by solvents which not only provide a medium for the chemical reactions but also facilitate reaching to the product stage. The solvent helps the reaction profile both chemically and energetically to reach the targeted product. Organic transformations via C−H activation from the solvent assistance perspective has been discussed in this review. Various solvents such as tetrahydrofuran (THF), MeCN, dichloromethane (DCM), dimethoxyethane (DME), 1,2‐dichloroethane (1,2‐DCE), dimethylformamide (DMF), dimethylsulfoxide (DMSO), isopropyl nitrile (ⁱPrCN), 1,4‐dioxane, AcOH, trifluoroacetic acid (TFA), Ac2O, PhCF3, chloroform (CHCl3), H2O, N‐methylpyrrolidone (NMP), acetone, methyl tert‐butyl ether (MTBE), toluene, p‐xylene, alcohols, MeOH, 1,1,1‐trifluoroethanol (TFE), 1,1,1,3,3,3‐hexafluoroisopropanol (HFIP), tert‐amyl alcohol and their roles are discussed. The exclusive role of the solvent in various transformations has been deliberated by highlighting the substrate scope, along with the proposed mechanisms. For easy classification, the review has been divided into three parts: (i) solvent‐switched divergent C−H activation; (ii) C−H bond activation with solvent as the coupling reagent, and (iii) C−H activation with solvent caging and solvent‐assisted electron donor acceptor (EDA) complex formation and autocatalysis.
A hydrophobic Ni‐PTFE modified electrode has been prepared by constant current and cathodic electroplating with a nickel sheet as substrate in a PTFE suspension. Then the Ni‐PTFE modified electrode was used for electroreduction from aromatic amide to diarylimide. The electrochemical characterizations such as cyclic voltammogram, EIS, polarization curves, and electrode stability have been carried out by electrochemical workstation. The structure of the electroreduction product diarylimide was characterized by ¹H NMR, FT‐IR, MS(Mass Spectrum), and EA(Elemental Analyzer). Based on the hydrophobicity of the electrode, an approach suggested that the phenyl ketone radical may be formed by electroreductive deamination at the cathode. With the construction of C−N bond by the radical coupling, the electrocatalytic reduction may be comprised of a one‐electron process including an ECC (Electrochemical‐Chemical‐Chemical) process. The electroreduction of aromatic amide to diarylimide may be controlled by both charge migration and concentration polarization. Electrocatalytic reduction of aromatic amides on Ni‐PTFE modified electrodes is all well conversion ratio.
Diphenolic acid/furfurylamine‐based bio‐benzoxazine (DPA‐fa‐Boz) was selected here as the starting material to prepare a phenol hydroxyl‐containing polyamide (PA) derivative, PA‐DFB, via sustainable benzoxazine‐isocyanide mechanochemistry (BIC‐MC). Further, a type of PA/phosphazene‐based, organic–inorganic covalent hybrid (PD‐HCCP), which comprises various N/P/O‐containing substructures (NP ring, amide, carboxylic acid, and tertiary amine), was successfully prepared by the condensation between PA‐DFB and hexachlorocyclotriphosphazene (HCCP). The presence of heteroatoms‐containing segments endows PD‐HCCP with specific affinity for some cationic agents. PD‐HCCP's binding capability for Pb(II) can be feasibly utilized for the detection of this heavy metal. The downstream application investigation of PD‐HCCP revealed that it can be used as an enrichment‐type Pb(II) electrochemical probe, characterizing a wide detection range (1–40 μM) and a low detection limit (0.0245 μM). Meanwhile, PD‐HCCP also showed the selective binding for cationic dye, methylene blue (MB), providing a maximum adsorption capacity of ~424.97 mg/g and a high adsorption rate (with 98% removal efficiency at 6 min), with the pseudo‐second‐order rate constant up to 0.0325 g mg ⁻¹ min ⁻¹ .
n‐Bu4NI/K2S2O8 mediated C−N coupling between aldehydes and amides is reported. A strong electronic effect is observed on the aromatic aldehyde substrates. The transformylation from aldehyde to amide takes place exclusively when an aromatic aldehyde bears electron‐donating groups at either the ortho or para position of the formyl group, while the cross‐dehydrogenative coupling dominates in the absence of these groups. Both the density functional theory (DFT) thermochemistry calculations and experimental data support the proposed single electron transfer mechanism with the formation of an acyl radical intermediate in the cross‐dehydrogenative coupling. The n‐Bu4NI/K2S2O8 mediated oxidative cyclization between 2‐aminobenzamide and aldehydes is also reported, with four quinazolin‐4(3H)‐ones prepared in 65–99 % yields.
Symmetrical aryl imides are synthesized from the reaction of activated amides such as N‐phenyl‐N‐tosyl benzamides. The amine source is provided by lithium hexamethyldisilazide (LiHMDS), and a 1,3‐diketone mediates the generation of the N‐acyl donor from N,N‐bis(trimethylsilyl)amide. Various symmetrical aryl amides are thus formed in moderate to good yields.
