Facile and Convenient One-pot Synthesis of 1,1-Disubstituted Cyclopropanes in Water

A facile and convenient one-pot synthesis method of substituted cyclopropanes in water has been developed.A series of 1,1-disubstituted cyclopropanes 3 were synthesized from the reaction of β-dicarbonyl compounds 1 with 1,2-dibromoethane 2,in very high yields catalyzed by tetrabutylammonium bromide(TBAB) at 50 oC in the presence of K2CO3 in water.The catalyst TBAB in the aqueous phase can be reused after the separation of organic products.     

A facile regioselective ring opening of aziridines to haloamines using tetrabutylammonium halides in the presence of β-cyclodextrin in water

A variety of N-tosylaziridines undergo regioselective ring opening with tetrabutylammonium halides in the presence of β-cyclodextrin in water at pH 4 and room temperature to afford the corresponding haloamines in excellent yields.     

Common methods for the chiral determination of amphetamine and related compounds I. Gas, liquid and thin-layer chromatography

This article reviews the most common, useful methods for the chiral determination of amphetamine (AM) and AM-derived designer drugs in different of matrix, including blood, hair, urine, medicaments or standard solutions, taking into consideration articles published in the past 15 years. We consider chromatographic methods (e.g., gas, liquid, high-performance liquid, and thin layer). We describe several types of chiral derivatization reagent, mobile-phase additive and chiral stationary phase commonly used in the chromatographic methods. Tables summarize basic information about conditions (e.g., type of column and mobile phase), detection mode and reference data for each procedure.     

Rapid and highly selective epoxidation of alkenes by tetrabutylammonium monopersulfate in the presence of manganese meso-tetrakis(pentafluorophenyl)porphyrin and tetrabutylammonium salts or imidazole co-catalysts

Epoxidation of various alkenes in low to high yields (29-100%) and good to excellent selectivities (75-100%) was performed with tetrabutylammonium monopersulfate in the presence of meso-tetrakis(pentafluorophenyl)porphyrin as catalyst and tetrabutylammonium acetate or fluoride or imidazole as co-catalysts in CH₂Cl₂, in less than 10 min at room temperature (∼25 °C).     

A simple procedure for the esterification of alcohols with sodium carboxylate salts using 1-tosylimidazole (TsIm)

An efficient and selective method for esterification of alcohols using N-(p-toluenesulfonyl)imidazole (TsIm) is described. In this method, alcohols are refluxed with a mixture of RCO₂Na (R: alkyl and aryl), TsIm, and triethylamine in the presence of catalytic amounts of tetra-n-butylammonium iodide (TBAI) in DMF to afford the corresponding esters in good yields. This methodology is highly efficient for various structurally diverse alcohols with selectivity for ROH: 1° > 2° > 3°.     

Binuclear iron(III) phthalocyanine(μ-oxodimer)/tetrabutylammonium oxone: a powerful catalytic system for oxidation of hydrocarbons in organic solution

Binuclear iron(III) phthalocyanine-(μ-oxodimer) complex was tested in catalytic oxygenation reactions of several hydrocarbons using tetrabutylammonium oxone as the oxidant in dichloromethane solution at room temperature. Results of the study demonstrate that this is an extremely powerful catalytic system for oxidative conversion of aromatic hydrocarbons (anthracene, 2-tert-butylanthracene, 2-methylnaphthalene, 9,10-dihydroanthracene, 1,2,3,4-tetrahydronaphthalene, indane, ethylbenzene, toluene, and benzene) to the respective p-quinones in high yields in 5-30 min. Under these conditions, adamantane is oxidized with 71% conversion after 10 min affording a mixture of 1-adamantanol, 2-adamantanone, 1-hydroxy-2-adamantanone, and 4-protoadamantanone.     

A simple and convenient method for the preparation of diborane from tetrabutylammonium borohydride and benzyl chloride for application in organic synthesis

Diborane is readily generated in situ at 25 °C in toluene using the Bu₄NBH₄/PhCH₂Cl and Bu₄NBH₄/I₂ reagent systems. The reagent prepared in this way is used for the reduction of carbonyl compounds and hydroboration-oxidation of olefins to obtain the corresponding alcohols in good yields.     

Silver electrodeposition from water–acetonitrile mixed solvents in the presence of tetrabutylammonium perchlorate

In this paper, surface-enhanced Raman spectroscopy has been used to investigate the electrode/electrolyte interface during Ag electrodeposition from water–acetonitrile mixed solvents. The reactivity of acetonitrile during Ag electrodeposition has been monitored, promoted by the electrocatalytic activity of silver clusters electrodeposited onto the electrode surface. The effect of the addition of tetrabutylammonium cations to the mixed solvents has been investigated and its adsorption and tilting on the silver surface has been followed as a function of the cathodic overpotential.     

Tetrabutylammonium Fluoride (TBAF) Catalysed Synthesis of 2‐Arylbenzimidazole in Water under Ultrasound Irradiation

One‐pot multistep reactions involving a new environmentally friendly catalytic procedure have been developed for the synthesis of benzimidazole. The reaction of the substituted aldehyde with o‐phenylenediamine in water under ultrasonic irradiation at ambient temperature for appropriate time using 5 mol% of TBAF furnish the desired product in good to excellent yield. The process is green, mild, inexpensive, excellent chemo selectivity, and excellent yields are the main advantages of this procedure.