The synthesis of di- and tri-arylamines through halogen displacement by base-activated arylamines: comparison with the Ullmann condensation

Abstract

In dipolar aprotic solvents, nitranions derived from anilines of enhanced N -acidity displace fluorine from activated aromatic compounds at room temperature. Diarylamines thus produced are free from triarylamines, which are formed at higher temperatures when diarylamines, after N-deprotonation b y potassium t-butoxide or by the heavier alkali metal carbonates, similarly displace activated fluorine. Certain diarylamines can also be prepared by chlorine displacement in the presence of alkali metal carbonates. It is confirmed that such carbonates play only an auxiliary role in the Ullmann (copperassisted) diarylamine synthesis conducted in dipolar aprotic solvents; they may indeed impede the reaction in some instances.Diarylamines are readily formed by the reaction of activated fluoroarenes with arylamines containing electron-releasing groups; ' the corresponding displacement of fluorine, nitro groups,, and the other halogens by arylamines containing electron-withdrawing groups requires activation of the amine by a base capable of effecting partial or complete removal of a proton from the acidic NH, group (Scheme 1). R'R 21) (2) (3) R', R2= electron-withdrawing groups M = a n alkali metal X = h a l o g e n or nitro group Scheme 1. Conditions: In dimethyl sulphoxide (DMSO): (A) at 12& 150 "C; (B) at 2 G -2 5 "C

Pd(II)-Catalyzed ortho- or meta-C–H Olefination of Phenol Derivatives

“…2,2′-azanediyldibenzonitrile was prepared by literature methods. 19 1 H and 13 C NMR spectra were recorded on Bruker AV 400, Varian Inova 400 (400 MHz and 100 MHz, respectively), Bruker DRX 500 (500 MHz and 125 MHz, respectively) and Bruker DRX 600 (600 MHz and 150 MHz, respectively) instruments. The peaks were internally referenced to TMS (0.00 ppm) or residual undeuterated solvent signal.…”

Synthesis and spectroscopy of anionic tridentate benzimidazole-pyridine carboxylate and tetrazolate chromophore ligands

“…This reaction takes advantage of the high reactivity of C-F bond in electron-deficient arenes [40][41][42]. An attempt to make carboxylate ligand 'HL8' from 4 worked for the first three steps (see the intermediates L8-NO 2 , L8-CH 2 OH, L8-CHO and the structure of ligand 'HL8' in the Supplementary material); however, oxidation of the carboxaldehyde L8-CHO to the carboxylic acid 'HL8' with H 2 O 2 in formic acid [26] resulted in oxidative decomposition, probably because of the presence of electron-rich diphenylamino group (Supplementary material).…”

Luminescent Sensing and Catalytic Performances of a Multifunctional Lanthanide‐Organic Framework Comprising a Triphenylamine Moiety

“…Synthesis and Crystal Growth: Tb − TCA: A mixture of 4,4′,4″-tricarboxytriphenylamine [ 21 ] (H 3 TCA) (94 mg, 0.25 mmol) and Tb(NO 3 ) 3 · 6H 2 O (453 mg, 1 mmol) were dissolved in 15 mL mixed solvents of dimethyl formamide (DMF) and ethanol in a screw-capped vial. The resulting mixture was kept in an oven at 100 ° C for 3 days.…”

“…It seems that, beside the base-type triphenylamine catalytic active sites, the interactions between SA and the Tb 3 + ions also exhibited excellent activities for this kind of Knoevenagel condensation. While a series of MOFs can catalyze the important reactions through isolated acid and/or base catalyzing forces, [ 21 ] the incorporation of both acid-and basecatalyzing forces within one channel is quite rare. The highest yield achieved in the channels demonstrates their signifi cant to directly enhance the catalytic effi ciency.…”