Tetrabutylphosphonium bromide

In addition to tetrabutylphosphonium chloride, typical phosphonium salts that can be produced include tetraoctylphosphonium bromide [23906-97-0], tetrabutylphosphonium acetate [17786-43-5] (monoacetic acid), and tetrabutylphosphonium bromide [3115-68-2]. Inmost cases, these compounds can be prepared with alternative counterions. 

As shown in Table IV, a number of well-known, single-site, ionic PTCs also catalyze the aromatic fluoroalkoxylation reaction, albeit at somewhat higher molar ratios than that required for the optimum conditions using PEG-8000. The most effective of these ionic materials was tetrabutylphosphonium bromide (TBPB) which is in agreement with a study by Bruneile (34c) on the PTC-mediated reaction of thiolates with polychlorobenzenes. It is interesting to note that solid-liquid conditions generally provided better conversions for the ionic PTCs than liquid-liquid conditions and that water... 

Data in Table I illustrate the production of acetic acid from 1/1 syngas catalyzed by ruthenium-cobalt halide bimetallic combinations dispersed in tetrabutylphosphonium bromide (m.p. 100°C). 

The ruthenium(111) acetylacetonate-cobalt(II) iodide couple, for example, when dispersed in tetrabutylphosphonium bromide (ex. 1) and treated with 1/1 CO/H2 at 220°C, generates a liquid product containing 76 wt % acetic acid plus 1.1 wt % propionic acid (111 mmol total acid). The liquid yield increase is 66% and the estimated carbon selectivity to acetic plus propionic acids and their esters is 84%. There is normally no metallic residue at this stage, ruthenium and cobalt recovery is essentially quantitative at the end of the run, and the product acids may be recovered in >90% purity by fractional distillation. Methane and water are the major by-products (4). 

It is clear that ruthenium-cobalt-iodide catalyst dispersed in low-melting tetrabutylphosphonium bromide provides a unique means of selectively converting synthesis gas in one step to acetic acid. Modest changes in catalyst formulation can, however, have profound effects upon liquid product composition. 

Reactions conducted in molten quaternary phosphonium salts require no other solvent (199). This material serves as both promoter and reaction medium. Care must be exercised in choosing the salt in such a reaction, since any decomposition could lead to products such as trialkylphosphines and alkyl halides which are expected to be deleterious to catalyst performance. Tetrabutylphosphonium bromide is reported to provide a stable catalyst medium which can be recycled (199, 200), but other related salts show evidence of thermal decomposition during catalytic reactions. Experiments in tetrabutylphosphonium acetate, for example, are found to produce large amounts of methyl and ethylene glycol acetate esters (199). 

Decarboalkoxylation Palladium(II) acetate, 232 Tetrabutylphosphonium bromide, 288 Decarbonylation (see also Elimination reactions)... 

In a subsequent investigation by others (1), tetrabutylphosphonium bromide was used as the phase transfer catalyst. 

Materials. Octamethylcyclotetrasiloxane, D4, was generously supplied hy General Electric Company. l,3-Bis(3-aminopropyl)tetramethyldisiloxane (to be referred to subsequently as aminopropyldisiloxane) was obtained from Petrarch Systems, Inc. These materials were dried over calcium hydride and vacuum distilled prior to use. Potassium hydroxide, tetramethylammonium hydroxide pentahydrate, and tetrabutylphosphonium bromide used in the preparation of the siloxanolate catalysts were used as received from Aldrich. 

The tetrabutylphosphonium siloxanolate catalyst was prepared by reacting the potassium siloxanolate catalyst with a solution of tetrabutylphosphonium bromide in toluene. The reaction resulted in a precipitate of KBr and the formation of homo-... 

With heating in the presence of aqueous HCl, alcohols add to the triple bond of phosphonylated nitriles to produce the corresponding iunidcs. - Several variations on the preparation of diethyl l-(thioacetamido)methylphosphonate by mercaptolysis of diethyl cyanomethylphosphonate have been reported. Best yields, up to 90%, are obtained by addition of H2S to a suspension of diethyl cyanomethylphosphonate, EtjN, and tetrabutylphosphonium bromide in toluene (Scheme 6.59). The early reported procedure using mercaptolysis at room temperature of a mixture of diethyl cyanomethylphosphonate, EtjN, and Py led to diethyl l-(thioacetamido)methylphosphonate in low to good yields (23-85%). The addition of cysteamine to the cyano group has also been reported. ... 

It has been demonstrated that 2,5-bis-(chloromethyl)-l,3,4-oxadiazole can undergo anionic polymerization. With sodium alcoholate, poly(l,3,4-oxa-diazole-2,5-diyl-l,2-vinylene) is formed, however the reaction cannot be controlled even at temperatures as low as —40°C. Instead, the exothermic reaction can be controlled by performing the polymerization at a toluene/ water interface with tetrabutylphosphonium bromide as a phase transfer catalyst. The mechanism is shown in Figure 10.7. 

Tetrabromocyclooctane, 155 Tetrabromovinylcyclohexene, 155 Tetrabutylammonium bromide, 98, 314 Tetrabutylammonium perchlorate, 17 Tetra-n-butylammonium tetrafluoroborate, 107, 110, 112 3,3, 5,5 -Tetra-tert-butyl biphenol, 240 Tetrabutylphosphonium bromide, 337 Tetrabutyl titanate, 435, 463... 

Phosphonium, tetrabutyl-, bromide. See Tetrabutylphosphonium bromide Phosphonium, tetrabutyl-, chloride. See Tetrabutylphosphonium chloride Phosphonium, tetrakis (hydroxymethyl)-, sulfate (2 1). See Tetrakis (hydroxymethyl) phosphonium sulfate... 

Uses Phase transfer catalyst, polymerization catalyst, chemical intermediate Manuf./Distrib. Cytec Ind. http //www.cytec.com Tetrabutylphosphonium bromide CAS 3115-68-2 EINECS/ELINCS 221-487-8 Synonyms Phosphonium, tetrabutyl-, bromide Tetra-N-butylphosphonium bromide Empirical CieHseBrP Formula (n-C4Hg)4PBr... 

Tetra-N-butylphosphonium bromide. See Tetrabutylphosphonium bromide Tetrabutylphosphonium chloride CAS 2304-30-5 EINECS/ELINCS 218-964-8 Synonyms Phosphonium, tetrabutyl-, chloride Empirical CisHseCIP Formula (n-C4Hg)4PCI... 

Benzyl trimethyl ammonium hydroxide Cetrimonium bromide Dimethyl diallyl ammonium chloride Laurtrimonium bromide Laurtrimonium chloride Methyl tributyl ammonium chloride Tetrabutyl ammonium bromide Tetrabutyl ammonium chloride Tetrabutyl ammonium fluoride Tetra-n-butyl ammonium hydrogen sulfate Tetra-n-butyl ammonium hydroxide Tetrabutyl ammonium iodide Tetrabutylphosphonium acetate, monoacetic acid Tetrabutylphosphonium bromide Tetrabutylphosphonium chloride Tetraethylammonium bromide Tetraethylammonium hydroxide Tetrakis (hydroxymethyl) phosphonium chloride Tetramethylammonium bromide Tetramethylammonium chloride Tetramethylammonium hydroxide Tetramethyl ammonium iodide Tetraphenyl phosphonium bromide Tetrapropyl ammonium bromide Tetrapropyl ammonium iodide Tributylamine Tributyl phosphine Tributyl (tetradecyl) phosphonium chloride Trioctyl (octadecyl) phosphonium iodide catalyst, phase-transfer Tetraethylammonium chloride Tetraoctylphosphonium bromide Tri-n-butyl methyl ammonium chloride Tri methyl phenyl ammonium hydroxide catalyst, phenolics Triethylamine... 

Sulfur dioxide Tall oil N-Tallow-1,3-diaminopropane dioleate Tallow nitrile Tetrabromophthalate diol Tetra-n-butoxysilane Tetrabutylphosphonium acetate, monoacetic acid Tetrabutylphosphonium bromide Tetrabutylphosphonium chloride 1,1,1,2-Tetrachloroethane... 

Tetrabutylphosphonium bromide 221-508-0 Bisolube TOPM Tri-2-ethylhexyl pyromellitate 221-515-9 Dichan 100... 

The preparation of ethylene glycol directly from synthesis gas via homogeneous rhodium (14-20), ruthenium (21-26), and cobalt (27-30) catalysis has generally been limited by the high pressures necessary to effect reaction and the modest turnover frequencies. We have demonstrated the preparation of ethylene glycol and its monoalkyl ether derivatives from CO/H2 (eq. 1) using ruthenium or a Ru-Rh catalyst combination dispersed in a low-melting quaternary phosphonium or ammonium salt such as tetrabutylphosphonium bromide. Monohydric alkanols are the major by-products data in Table 1 illustrate typical preparations. The important features of this catalysis are ... 

Data in Table V illustrate the production of acetic acid from 1/1 syngas. A variety of ruthenium-containing precursors - coupled with cobalt halide, carbonate and carbonyl compounds - at different initial Co/Ru atomic ratios, have been found to yield the desired carboxylic acid when dispersed in tetrabutylphosphonium bromide. In a more detailed examination of the ruthenium-cobalt-iodide melt catalyst system, we have followed the generation of acetic acid and its acetate esters as a function of catalyst composition and certain operating parameters, and examined the spectral properties of these reaction products, particularly with regard to the presence of identifiable metal carbonyl species. 

Ruthenium(IV) oxide - n-heptyltriphenylphosphonium bromide combinations (expt. 1) display the highest selectivity to ethyl propionate achieved so far in this work (60% of the total C1-C4 alkyl propionate fraction) under our preferred operating conditions. Fastest reaction rates are realized with ruthenium(IV) oxide tetrabutylphosphonium bromide (expt. 3) here the ethyl product fraction appears both as ethyl propionate and, in the presence of insufficient acid, as unester-ified ethanol (expt. 2). 

Table IX illustrates the generation of N,N-dimethylformamide (DMF) and N-methylformamide (MMF), plus formamide, using different ruthenium catalyst precursors dispersed in tetrabutylphosphonium bromide and iodide. In the first entry, treatment of the Ru3(C0)x2 Bu4PI dispersion with CO/H2/NH3 at 220 C for 4 h yielded a liquid product comprising 24% DMF and 43% MMF. The liquid yield increase was 112%. Entry 2...

Typical hydroformylation activity is illustrated in Table XII for a model, internal, linear-backbone, olefin mixture (2-, 3- and 4-octenes) using as catalyst precursor, a dispersion of ruthenium(IV) oxide, hydrate in tetrabutylphosphonium bromide (expt. 1). Optionally, a cobalt carbonyl-tertiary phosphine cocatalyst may be added (expt. 

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