Tetrabutyl

A/B = alkylated ben2enes TBU = tetrabutyl urea TOP = trioctyl phosphate and DIBC = diisobutyl carbinol. See text. 

Twelve-membered rings have been obtained using coordination catalysts. The transJmns,ds-cyc. ododec2Lti ien.e has been prepared with a tetrabutyl titanate—diethylalurninum chloride catalyst (48,49) and with a chromium-based system (50). The trans,trans,trans-isom.e-i. has been prepared with a nickel system. 

It is shown that both Sb(III) and Bi(III) can speed reduction of 12-molybdophosphate (12-MPC) to the corresponding heteropoly blue (12-MPB) by ascorbic acid (AA). It is found that mixed polyoxometalates can be formed in solution which reduce considerably more rapidly than 12-MPC. Complete formation of mixed POM is observed only if significant excess of Me(III) ions is used in the reaction. POM responsible for blue color was synthesized by selective extraction. Chemical analysis of tetrabutyl-ammonium salt is in accordance with formula of (TBAl PMeflllfMo O j (Me = Sb, Bi). IR spectmm of mixed POM is identical to 12-MPC. 

In contrast to the nature of TBAF, tetrabutylammoniuin bifluoride converts benzyl bromide to its fluoride in 100% yield and 4-chloronitrobenzene to 4 fluoronitrobenzene in 70% yield 1-Bromodecane is transformed by tetrabutyl-atnmonium bifluoride to 1-fluorodecanein 88% yield, and Tchlorododecane forms 1-fluorododecane m 83% yield In neither case are significant amounts of the elimination products formed [25]... 

Reactions of ar>l or alkyl bis(siloxy)isopropyl ethers with tetrabutyl-ammoninm fluoride-mesyl fluoride reagent lead to replacement of one siloxy group by fluorine and dehydrosiloxylation, providing an efficient access to fluoroisopropenyl ethers, which are useful as specific building blocks in drug design The reactions proceed via the intermediate allyl methanesulfonates [30, 31] (equation 23)... 

Trimethylsilylethynylpyrazole was deprotected by treatment with tetrabutyl-ammonium fluoride (TBAF) to give monosubstituted acetylene in 90% yield. (96ADD193). The same conditions were used to cleave the trimethylsilyl group in l-tetrahydropyranyl-3-carboxyethyl-4-[2-(trimethylsilyl)ethynyl]pyrazole (96INP 9640704). 

Intramolecular cyclization of 2-phenysulfonylmethyl lactam 3 took place upon reaction with lithium hexamethyldisilazan via generating its a-sulfonyl carbanion to give a cyclized postulated intermediate that can be quenched with trimethylchlorosilane to afford the stable silyl ketal 4. The later ketal was desulfonylated by Raney-Ni and desilylated through treatment with tetrabutyl ammonium fluoride (BU4NF) to afford the carbacephem 5 (94M71) (Scheme 1). 

The polarographic determination of metal ions such as Al3 + which are readily hydrolysed can present problems in aqueous solution, but these can often be overcome by the use of non-aqueous solvents. Typical non-aqueous solvents, with appropriate supporting electrolytes shown in parentheses, include acetic acid (CH3C02Na), acetonitrile (LiC104), dimethylformamide (tetrabutyl-ammonium perchlorate), methanol (KCN or KOH), and pyridine (tetraethyl-ammonium perchlorate), In these media a platinum micro-electrode is employed in place of the dropping mercury electrode. 

Two approaches for the synthesis of allyl(alkyl)- and allyl(aryl)tin halides are thermolysis of halo(alkyl)tin ethers derived from tertiary homoallylic alcohols, and transmetalation of other allylstannanes. For example, dibutyl(-2-propenyl)tin chloride has been prepared by healing dibutyl(di-2-propenyl)stannane with dibutyltin dichloride42, and by thermolysis of mixtures of 2,3-dimethyl-5-hexen-3-ol or 2-methyl-4-penten-2-ol and tetrabutyl-l,3-dichlorodistannox-ane39. Alternatively dibutyltin dichloride and (dibutyl)(dimethoxy)tin were mixed to provide (dibutyl)(methoxy)tin chloride which was heated with 2,2,3-trimethyl-5-hexen-3-ol40. 

Zur Zersetzung dcs Adduktes wird auch Tetrabutyl-ammonium-acetat empfohlen, das in der Reaktionsmi-schung gut loslich ist3. 

Ohne solvatisierte Elektronen kommt man bei der kathodischen Hydrierung von An-thracen zum 9,10-Dihydro-antfiracen aus (Acetonitril mit Tetrabutyl-ammoniumbromid als Elektrolyt)4. 

Selektiv wird 6,6 -Diacetyl-5,5 -bi-acenaphthenyl in 1,4-Dioxan/Athanol/Tetrabutyl-ammoniumchlorid an Quecksilber bei - 1,9 Volt zu 6 -(l-Hydroxy-athyl)-6-acetyl-5,5 -bi-acenaphthenyl (71% d.Th.) reduziert4 ... 

Auf ahnliche Weise erhalt man am Blei aus Aceton Tetraisopropyl-1 bzw. Tetrabutyl-(2)-blei aus Butanon8. 

Bei relativ niedrigem Kathodenpotcntial wird Anthracen zum Anion-Radikal reduziert (DMF/Tetrabutyl-ammoniumjodid, Ouecksilber), das dann verschiedene Sulfone reduktiv spalten kann . 

Tetraathyl- 624 Tetrabutyl-(2)- 609 Tetrakis-[2-cyan-athyl]- 624 Tetraisopropyl- 609 Tetramethyl- 624 Trimethyl- -chlorid 486 Trimethyl- -hydrid 486... 

The peak capacity is not pertinent as the separation was developed by a solvent program. The expected efficiency of the column when operated at the optimum velocity would be about 5,500 theoretical plates. This is not a particularly high efficiency and so the separation depended heavily on the phases selected and the gradient employed. The separation was achieved by a complex mixture of ionic and dispersive interactions between the solutes and the stationary phase and ionic, polar and dispersive forces between the solutes and the mobile phase. The initial solvent was a 1% acetic acid and 1 mM tetrabutyl ammonium phosphate buffered to a pH of 2.8. Initially the tetrabutyl ammonium salt would be adsorbed strongly on the reverse phase and thus acted as an adsorbed ion exchanger. During the program, acetonitrile was added to the solvent and initially this increased the dispersive interactions between the solute and the mobile phase. 

As the acetonitrile concentration increased, however, the concentration of adsorbed tetrabutyl ammonium salt would also be reduced and it would be desorbed from the reverse phase with a resulting reduction in the ionic interactions of the solutes with the stationary phase. At higher concentrations of acetonitrile, the tetrabutyl ammonium salt would be completely desorbed from the stationary phase and the interactions of the solutes with the stationary phase would become almost exclusively dispersive. This is an example... 

Benzofurans have been prepared by microwave-accelerated cyclocondensation of differently substituted salicylaldehydes 182 with esters of chloroacetic acid 183 in the presence of K2CO3 (used as the solid support) and tetrabutyl-ammonium bromide (TBAB) as phase transfer catalyst [120]. This method seemed general regarding the variations at the benzene ring and the nature of the ester moiety (Scheme 66). 

As these solid agents, some quaternary ammonium tribromides such as pyridinium hydrobromide perbromide (ref. 1), phenyltrimethylammonium tribromide (ref. 2), tetramethylammonium tribromide (ref. 3), and tetrabutyl-ammonium tribromide (ref. 4) have already been reported as mild and selective brominating agents (Fig. 1). 

In the as-synthesized MFI-crystals the tetrapropylammonium (TPA) ions are occupying the intersections between the straight (parallel) and the sinusoidal channels of the zeolite, thus providing an efficient pore filling. The detailed structure of as-synthesized MFI-TPA has been elucidated by X-ray single crystal analysis (ref. 3). Also the combination tetrabutyl-Ztetraethylammonium can be applied as template in MFI-synthesis. A 1 1 build-in is found then (Fig. 1). When only tetrabutylammonium is available as template, the MEL (ZSM-11) lattice is formed with another distance between the channel intersections. 

Figure 1. Structure-directing quats in the MFI-lattice right, the usually applied tetrapropyl-anunonium, left, tetrabutyl- and tetraehtylammonium 1 1.

Tetrabutylammonium hydrogen sulfate Ammonium, tetrabutyl-, sulfate (1 1) (8) 1-Butanaminium, N,Af,N-tributyl-, sulfate (1 1) (9) (32503-27-8)... 

The sodium and potassium salts of glutaconaldehyde are soluble only in polar solvents such as water, dimethyl sulfoxide, N,N-dimethylformamide, pyridine, and methanol. However, the stable tetrabutylammonium salt is soluble in relatively nonpolar solvents such as chloroform and ethyl acetate. It may be prepared from the potassium salt in the following manner. In a 1-1. Erlenmeyer flask equipped with a magnetic stirring bar are placed a solution of 13.6g. (0.1 mole) of crude glutaconaldehyde potassium salt in 200 ml. of water and a solution of 33.9 g. (0.1 mole) of tetrabutyl-ammonium hydrogen sulfate in 200 ml. of ice-cold water, the pH of wliich was adjusted to 10 by adding aqueous 2M sodium hydroxide. 

The first example deals with poly[bis(trifluoroethoxy)phosphazene],PTFEP, film, whose surface is intrinsically hydrophobic but can be converted to hydrophilic by the action of NaOH in dioxane at 80 °C in the presence of tetrabutyl-ammonium bromide [514,515], or by metathetical exchange of trifluoroethoxy moieties with variable types of alkoxides groups [482,483,515] (vide supra). 

The copolymerization parameters for copolymerization of dilactide and e-caprolactone catalyzed by stannous octoate, stannous chloride, and tetrabutyl titinate have been determined (5). 

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