Tetra-n-butylammonium bromide TBAB

The following quaternary ammonium salts are used as phase transfer catalyst tetra-K-butylammonium chloride (TBAC), tetra-n-butylammonium bromide (TBAB), benzyltriethylammonium chloride (BTEAC), and benzyltriethylammo-nium bromide (BTEAB). Chlorinated hydrocarbons, such as dichloromethane (DCM), chloroform (CF), tetrachloromethane (TCM), 1,2-dichloromethane (DCE), and nitrobenzene (NB) are used as solvents. The effects of phase-transfer catalyst and solvent on the yield and reduced viscosity are summarized in Table 9.1. 

Onium salts, such as tetraethylammonium bromide (TEAB) and tetra-n-butylammonium bromide (TBAB), were also tested as PTCs immobilized on clay. In particular, Montmorillonite KIO modified with TBAB efficiently catalyzed the substitution reaction of a-tosyloxyketones with azide to a-azidoketones, in a biphasic CHCI3/water system (Figure 6.13). ° The transformation is a PTC reaction, where the reagents get transferred from the hquid to the solid phase. The authors dubbed the PTC-modified catalyst system surfactant pillared clay that formed a thin membrane-hke film at the interface of the chloroform in water emulsion, that is, a third liquid phase with a high affinity for the clay. The advantages over traditional nucleophilic substitution conditions were that the product obtained was very pure under these conditions and could be easily recovered without the need for dangerous distillation steps. 

Materials. CEVE and 4-nitrophenyl vinyl ether (VNP) were synthesized and purified as reported earlier (12,13), respectively. 2-(4-Nitrophenoxy)ethyl vinyl ether (NPVE) (m.p. 72-73°C) was prepared by reacting of potassium 4-nitrophenoxide (PNP) (142 g 0.8 mol) and CVE (842 g 7.9 mol) using tetra-n-butylammonium bromide (TBAB) (4.0 g 12 mmol) as a phase transfer catalyst at the boiling temperature of CVE for 12 h. The potassium chloride produced was filtered off, the filtrate washed with water, excess CVE evaporated, and then the crude product was recrystallized twice from n-hexane. (Yield 61.7%. IR (KBr) 1630 (C=C), 1520 (-N02), and 1340 cm-1 (-N02).) Elemental analysis on the product provided the following data Calculated for C10HnNO4 C, 57.40%, H, 5.30%, N, 6.69%. Found C, 57.49%, H, 5.3%, N, 6.72%. 

It was found that sodium salt (II) can be easily and cleanly monoalkylated with a variety of polyfunctional organic halides under strictly anhydrous conditions. The reactions are generally carried out in refluxing benzene in the presence of 10 mol-% of tetra-n-butylammonium bromide (TBAB) as phase-transfer catalyst ... 

Methylbenzenes can readily be transformed into benzoic acids at room temperature upon exposure to aqueous sodium hypochlorite at pH 9-10 in the presence of RuC13 and tetra-n-butylammonium bromide (TBAB) catalysts in a two-phase system (Eq. 6) [39]. The proposed mechanism for the Ru-NaOCl phase transfer catalyst system is a hydride abstraction from the substrate by Ru04 to form a carbonium ion which is promptly hydrolysed. A major... 

Li X-S, Xia Z-M, Chen Z-Y, Wu H-J (2011) Precombustion capture of carbon dioxide and hydrogen with a one-stage hydrate/membrane process in the presence of tetra-n-butylammonium bromide (TBAB). Energy Fuels 25(3) 1302-1309... 

The complex Pd(II)-(di-2-pyridyl)methylamine 44 allows Suzuki coupling in aqueous media, using K2CO3 or KOH as a base in the presence of tetra-n-butylammonium bromide (TBAB) [127]. A range of aryl bromides and chlorides. 

Tetrabutyl ammonium bromide CAS 1643-19-2 EINECS/ELINCS 216-699-2 Synonyms 1-Butanaminium, N,N,N-tributyl-, bromide TBAB Tetra-N-butylammonium bromide... 

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