Tri-n-butylammonium

Tri-n-butylammonium nitrate [33850-87-2] IVI 304.5. Crystd from mixtures of n-hexane and acetone (95 5). Dried over P2O5. 

Activities of tri-n-butylammonium and tri-n-butylphosphonium ions with two different spacer chain lengths are compared in Table 8 1I8). The greater activity of the phosphonium ions is opposite to what has been reported for analogous soluble phase transfer catalysts119). Activities of the catalysts bound to silica gel were as high as activities of soluble catalysts adsorbed to silica gel118). Without some independent determination of the role of intraparticle diffusion it is not possible to determine whether the reduced activity of the adsorbed catalysts is due to lower intrinsic activity at the silica gel surface or to diffusional limitations. The size selectivity for alkyl bromides suggests that intraparticle diffusion was not a problem. 

Alumina also has been used as a support for tri-n-butylammonium and tri-n-butylphosphonium ion catalysts 32 and 33, prepared by the same method used with silica gel U8>. 

Tri-n-butylammonium perchlorate [14999-66-7] M 285.5. Recrystd from n-hexane. sy/n-Triterr-butyl benzene [1460-02-2] M 246.4, m 73.4-73.9°. Crystd from EtOH. 

The starting material was the tri-n-butylammonium salt of 2-deoxy-[(3R)-3-hydroxytetradecanamido]-a-D-glucopyranosyl phosphate which was condensed with... 

QH4B5O10 n HaO (n = 1 Q = Tetraallylammonium, Triallyl-n-propylam-monium, = 3 Q = Trimethyl-l-acenaphthenylammonium, Benzyltriathylam-monium und Benzyl-tri-n-butylammonium) oder... 

Eine Reihe von Heptaboraten mit den organischen Kationen Tetra-n-propylammonium-, Tetra-n-butylammonium-, Dimethylbenzyl-n-pro-pylammonium, Tri-n-butylammonium und Dimethylbenzylammonium 202) wurde durch Boresterhydrolyse erhalten. Die Struktur des Insel-polyborations [B706(OH)xo] ist schwer vorstellbar, und es ist gut mog-lich, daB sich dieses Ion aus zwei schon bekannten Inselpolyborationen... 

Although the treatment of a phosphorodichloridate with the tri-n-butylammonium salt of phosphoric acid seems a plausible route to nucleoside diphosphates, this has recently been shown instead to be a means of preparing the triphosphate.8 Probably the most reliable method for preparing diphosphates is that described by Poulter,9 in which the tetra-n-butylammonium salt of a nucleophilic phosphorus component, for example, pyrophosphate is reacted with a nucleoside 5 -tosylate in acetonitrile (Figure 9.2). 

Following phosphorylation using the Yoshikawa procedure, the reaction of pyrophosphate with the intermediate phosphorodichloridate followed by aqueous work-up provides a convenient one-pot synthesis for triphosphates. With slight modification to this procedure, thiophosphoryl chloride can be used in place of phosphoryl chloride to give 5 -( 1 -thio)triphosphates as a mixture of two diaste-reoisomers (.S p and Rp). Both procedures require the prior preparation of the DMF-soluble, bis(tri-n-butylammonium) salt of pyrophosphate. This is prepared as a 0.5 M solution, can be stored in the fridge and is converted to its terrafcis(tri-n-butylammonium) salt immediately prior to reaction. Rates of nucleoside phosphorylation vary considerably and it is necessary to monitor the formation of the phosphorodichloridate during the Yoshikawa procedure in order... 

Di-(2-Athylhexyl)phosphorsaure eignet sich flit die selektive Ab-trennung des Strontiums von Calcium und wurde sowohl in det radio-chemischen Analyse (76) als auch im technischen MaBstab hierzu ver-wendet (359). Die Ttennung des Silbers von Blei gelingt dutch Extraktion als Tributylammonium-silberrhodanid (632), wahrend Eisen als Tri-n-butylammonium-hexarhodanoferrat(III) (625) von Aluminium entfemt wird. 

The results clearly indicate that quenching of benzophenone triplets in polar solvents is a bimolecular process. This means that the ions exist mostly as separated ions and that the electron transfer process occurs mainly as an inter-ion-pair reaction [66, 67]. Analysis of the products after irradiation of A-(p-benzoylbenzyl)-A,A,N-tri-n-butylammonium triphenyl-n-butylborate (BTAB, Figure 14) indicates formation of p,p -(benzoyl)dibenzyl, p-pentylbenzophenone and tributylamine. This indicates that electron transfer from the borate anion to the acceptor excited state leads to homolytic C-N bond scission and formation of the tertiary amine. 

Novel 2 -modified nucleoside triphosphate derivatives incorporating imidazole, amino or carboxylate pendant groups attached to the 5-position of pyrimidine base through alkynyl and alkyl spacers (115) have been synthesised. In one reported procedure, the appropriately protected modified nucleoside was phosphorylated with POCI3 in triethylphosphate in the presence of 1,8-bis(dimethylamino)naphthalene. The phosphorochloridate intermediate was then condensed in situ with tri-n-butylammonium pyrophosphate to yield the protected triphosphate analogue that was then deprotected. In another... 

By contrast with the above conditions, the oxidation of 2,6-di-tert-butylphenol in 50% aqueous potassium hydroxide containing 50% aqueous methyl tri-n-butylammonium chloride in a sealed reactor at 200 C and 300 psig. for 1 hour with 50%hydrogen peroxide has been reported to give 4,4 -bis(2,6-di-tert-butylphenol) the precursor of the diphenoquinone in 97.5% yield (ref.3). 

Ion-pair extraction. Iodides are extracted into methylene chloride or similar solvents much more readily than the corresponding chlorides. This ion-exchange method is used to convert trimethyloxosulfonium iodide into the chloride. Thus on distribution of this iodide and an equimolecular amount of the quaternary chloride between methylene chloride and water, the organic phase contains benzyl tri-n-butylammonium iodide and the water phase contains trimethyloxosulfonium chloride. The ion exchange is practically complete. Note that trimethyloxosulfonium chloride is preferred to the iodide for generation of dimethyloxosulfonium methylide because the chloride is more soluble in THF (1,315). ... 

Scheme 95). The trimethyl silyl-protecting group was removed using tri-n-butylammonium fluoride (TBAF) followed by lithiation and methylation forming (56). Addition of phenyl methyllithium sulfone gave a 94% de after decom-plexation (57). 

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