Tris tetra-n-butylammonium

ALLYLIC PYROPHOSPHATES Tris-(tetra-n-butylammonium)hydrogcn pyrophosphate. 

The synthesis of nucleoside diphosphates is best achieved using the Poulter reaction,9 which involves reaction of the tris(tetra-n-butylammonium) salt of pyrophosphate with a nucleoside 5 -tosylate in acetonitrile. A general procedure for the synthesis of nucleoside tosylates of thymidine and 2 -deoxyadenosine is included (Protocol 15), whilst the syntheses of the other tosylates (including ribonucleosides) have been described using related procedures. Simple modification of the protocol, whereby the tetra-n-butylammonium salt of pyrophosphoric acid is replaced by methylene or difluomethylene bis phosphonate, allows the synthesis of hydrolytically stable dNTP analogues.10... 

Add more dry acetonitrile if necessary so that the total volume of the pyrophosphate solution in step 9 is 4 mL. This gives a 1.5 M solution of tris(tetra-n-butylammonium) pyrophosphate. 

Reagents (a) tris(tetra-n-butylammonium)thiopyrophosphate, CH3CN (b) dowex AG 50W-X8 (NH form). 

Tri(tetra-n-butylammonium)hexacyanoferrate(IlI), (BuaNlsFeCCN) (1). Mol. wt. 938. Soluble in CHCI3, CH3OH. 

Tris(phenylthio)methyllithium, 650-651 Tris(tetra-n-butylammonium)hexacyano-ferrate(lll), 656... 

C5i,H3 1NO18P2RU6, Bis(triphenylphosphine)amine octadecacarbonylhydro-gen-octahedro-hexaruthenate, 46B, 1342 C5osNgSsTc, Tris(tetra-n-butylammonium) hexakis(isothiocyanato)-technetiumdll), 46B, 1137... 

Water samples showing contamination by phenols are best examined by extracting the phenol into an organic solvent tri-n-butyl phosphate is very suitable for this purpose. Photometric measurements can be carried out on the extract, and the requisite alkaline conditions are achieved by the addition of tetra-n-butylammonium hydroxide. 

Prepare an alkaline solution of the phenol concentrate by placing 4.0 mL of a tri-n-butyl phosphate layer in a 5 mL graduated flask and then adding 1.0 mL of the tetra-n-butylammonium hydroxide do this for each of the four solutions. The reference solution consists of 4 mL of the organic layer (in which the phenol is undissociated) plus 1 mL of methanol. Measure the absorbance of each of the extracts from the four test solutions and plot a calibration curve. 

The highly hydrophilic alcohols, pentaerythritol and 2-ethyl-2-hydroxymethyl-propan-l,3-diol, can be converted into their corresponding ethers in good yields under phase-transfer catalytic conditions [12]. Etherification of pentaerythritol tends to yield the trialkoxy derivative and kinetics of the reaction have been shown to be controlled by the solubility of the ammonium salt of the tris-ether in the organic phase and the equilibrium between the tris-ether and its sodium salt [13]. Total etherification of the tetra-ol is attained in good yield when reactive haloalkanes are used, and tetra-rt-octylammonium, in preference to tetra-n-butylammonium, bromide [12, 13]. 

Compared with primary and secondary amines, tertiary amines are virtually unreac-tive towards carbenes and it has been demonstrated that they behave as phase-transfer catalysts for the generation of dichlorocarbene from chloroform. For example, tri-n-butylamine and its hydrochloride salt have the same catalytic effect as tetra-n-butylammonium chloride in the generation of dichlorocarbene and its subsequent insertion into the C=C bond of cyclohexene [20]. However, tertiary amines are generally insufficiently basic to deprotonate chloroform and the presence of sodium hydroxide is normally required. The initial reaction of the tertiary amine with chloroform, therefore, appears to be the formation of the A -ylid. This species does not partition between the two phases and cannot be responsible for the insertion reaction of the carbene in the C=C bond. Instead, it has been proposed that it acts as a lipophilic base for the deprotonation of chloroform (Scheme 7.26) to form a dichloromethylammonium ion-pair, which transfers into the organic phase where it decomposes to produce the carbene [21]. 

Complex iron(III) salts are frequently used in oxidative arene coupling reactions and quinone formation and tetra-n-butylammonium hexacyanoferrate(III) has several advantages in it use over more conventional oxidative procedures. When used as the dihydrogen salt, Bu4N[H2Fe(CN)6], it oxidizes 2,6-di-z-buty 1-4-methylphenol (1) to the coupled diarylethane (2), or aryl ethers (3) and (4) (Scheme 10.4), depending on the solvent. It is noteworthy that no oxidation occurs even after two days with the tris-ammonium salt. 

Reductive metallation of aldehydes (but not ketones) by tri-n-butyl-(trimethyisilyl)stannane to yield a-hydroxystannanes is catalysed by tetra-n-butylammonium cyanide [15]. Other phase-transfer catalysts are not as effective and solvents, other than tetrahydrofuran, generally give poorer conversions. Use of a chiral catalyst induced 24% ee with 3-phenylpropanal. 

By media variables we mean the solvent, electrolyte, and electrodes employed in electrochemical generation of excited states. The roles which these play in the emissive process have not been sufficiently investigated. The combination of A vV-dimethylformamide, or acetonitrile, tetra-n-butylammonium perchlorate and platinum have been most commonly reported because they have been found empirically to function well. Despite various inadequacies of these systems, however, relatively little has been done to find and develop improved conditions under which emission could be seen and studied. Electrochemiluminescence emission has also been observed in dimethyl sulfite, propylene carbonate, 1,2-dimethoxyethane, trimethylacetonitrile, and benzonitrile.17 Recently the last of these has proven very useful for stabilizing the rubrene cation radical.65,66 Other electrolytes that have been tried are tetraethylam-monium bromide and perchlorate1 and tetra-n-butylammonium bromide and iodide.5 Emission has also been observed with gold,4 mercury,5 and transparent tin oxide electrodes,9 but few studies have yet been made1 as to the effects of electrode construction and orientation on the emission character. 

Tris(tetra-n-buty (ammonium) hydrogen pyrophosphate, 1(ihC4H,)4N]3HP207 (1). Mol. wt. 417.42. The salt is prepared by treatment of Na2H,P,07 (Stauffer) with an acidic ion-exchange resin and then with tetra-n-butylammonium hydroxide. 

NMO NMP Nu PPA PCC PDC phen Phth PPE PPTS Red-Al SEM Sia2BH TAS TBAF TBDMS TBDMS-C1 TBHP TCE TCNE TES Tf TFA TFAA THF THP TIPBS-C1 TIPS-C1 TMEDA TMS TMS-C1 TMS-CN Tol TosMIC TPP Tr Ts TTFA TTN N-methylmorpholine N-oxide jV-methyl-2-pyrrolidone nucleophile polyphosphoric acid pyridinium chlorochromate pyridinium dichromate 1,10-phenanthroline phthaloyl polyphosphate ester pyridinium p-toluenesulfonate sodium bis(methoxyethoxy)aluminum dihydride (3-trimethylsilylethoxy methyl disiamylborane tris(diethylamino)sulfonium tetra-n-butylammonium fluoride f-butyldimethylsilyl f-butyldimethylsilyl chloride f-butyl hydroperoxide 2,2,2-trichloroethanol tetracyanoethylene triethylsilyl triflyl (trifluoromethanesulfonyl) trifluoroacetic acid trifluoroacetic anhydride tetrahydrofuran tetrahydropyranyl 2,4,6-triisopropylbenzenesulfonyl chloride 1,3-dichloro-1,1,3,3-tetraisopropyldisiloxane tetramethylethylenediamine [ 1,2-bis(dimethylamino)ethane] trimethylsilyl trimethylsilyl chloride trimethylsilyl cyanide tolyl tosylmethyl isocyanide meso-tetraphenylporphyrin trityl (triphenylmethyl) tosyl (p-toluenesulfonyl) thallium trifluoroacetate thallium(III) nitrate... 

Sodium borohydride-Palladium chloride. Sodium borohydride-Rhodium(lII) chloride. Sodium borohydride-Tin(II) chloride. Sodium cyanoborohydride. Sodium 9-cyano-9-hydrido-9-borabicyclo[3.3.1]nonane. Sodium dithionite. Sodium hydride-Sodium t-amyl oxide-Zinc chloride. Sodium trimethoxyborohydride. Tetra-/i-butylammonium borohydride. Tetra-n-butylammonium cyanoborohydride. Tetra-n-butylammonium octahydrotriborate. Tri-n-butyltin hydride. Triethoxy silane. Triisobutylaluminum-Bis(N-methyl-salicyclaldimine)nickel. Zinc borohydride. REDUCTIVE CYCLIZATION Cobaloximc(I). 

The phenomena enumerated in Section 2.4 do not, of course, fully describe all the differences between chemical and electrode processes of ion radical formation. From time to time, effects are found that cannot be clearly interpreted and categorized. For instance, one paper should be mentioned. It bears the symbolic title ir- and a-Diazo Radical Cations Electronic and Molecular Structure of a Chemical Chameleon (Bally et al. 1999). In this work, diphenyldiazomethane and its 15N2, 13C, and Di0 isotopomers, as well as the CH2-CH2 bridged derivative, 5-diazo-10,ll-dihydro-5H-dibenzo[a,d]cycloheptene, were ionized via one-electron electrolytic or chemical oxidation. Both reactions were performed in the same solvent (dichloromethane). Tetra-n-butylammonium tetrafluoroborate served as the supporting salt in the electrolysis. The chemical oxidation was carried out with tris(4-bromophenyl)-or tris(2,4-dibromophenyl)ammoniumyl hexachloroantimonates. Two distinct cation radicals that corresponded to it- and a-types were observed in both types of one-electron oxidation. These electromers are depicted in Scheme 2-28 for the case of diphenyldiazomethane. 

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... 

When alkylammonium salts are recrystallized from water, they often form solids with very low melting points (Fowler et al., 1940). An example is (iso-Am)4N+.F- 40 H20 whose structure (Feil and Jeffrey, 1961) shows that the amyl groups are held in cages of water molecules located tetrahedrally around the N+-charge centre of the onium ion (Fig. 11). Similar structures are observed in tetra-n-butylammonium (McMullan et al., 1963 Bonamico et al., 1962) and tri-n-butylsulphonium salt hydrates (Beurskens and Jeffrey, 1964). 

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). 

It is a palladium-catalyzed cross-coupling reaction between organosilanes (vinyl, ethynyl and allylsilanes) and organic halides (aryl, vinyl and allyl halides). Allylpal-ladium chloride dimmer [( ri -C3H5PdCl)2] and either tris(diethylamino)sulfonium difluorotrimethylsilicate (TASF) or tetra-n-butylammonium fluoride (TBAF) are used as catalysts. Fluoride ion acts as an activator for the coupling, forming an intermediate hypervalent anionic silicon species, which can then transmetallate with palladium as a preliminary reaction to coupling. 

Dichlorocarbene addition to aikenes. Dehmiow and LisseP have examined the reaction variables in the generation of dichlorocarbene by PTC. Optimal conditions include use of 4 molar excess each of CHCI3 and 50% aqueous NaOH, 1 mole % of catalyst, and efficient stirring. The reaction should be conducted initially at 0-5°, then at 20° for 1-2 hours, and finally at 50° for 2-4 hours. Most quaternary ammonium salts are suitable as catalysts the anions should be chloride or hydrogen sulfate. From the point of cost/efficiency, the most useful are benzyltriethylammonium chloride, tetra-n-butylammonium chloride, Aliquat 336, and tri-n-propylamine. The reaction rate is strongly dependent on the nucleophilicity of the alkene. 

HOMOALLYLIC ALCOHOLS Allyl tri-methyltin. lodomethyltri-n-butyltin. (+)-3-Phenyl-2,3-bornanediol. Tetra-n-butylammonium fluoride. 

Tin-capped clathrochelate cobalt(III) tris-dioximates were synthesized by a procedure similar to Reaction 1 in the presence of organic bases (amines or tetra-n-butylammonium hydroxide) ... 

Lithium iso -amyl, LiCgH, reacts with triethyl-n-butylammonium bromide to give diethyl-n-butylamine and lithium n-heptyl, with tetra-n-butylammonium iodide to form tri-n-butylamine, a trace of a hydrocarbon and possibly n-heptane. 

Thallium(I) cyanide was introduced by Taylor and McKillop as a reagent. Aromatic and heteroaromatic acyl cyanides are produced in go yield, whereas aliphatic acid halides lead under these conditions mainly to dimerization products. 18-Crown-6 is a good catalyst for the preparation of cyanoformate in methylene chloride with potassium cyanide and chloroformates. Similarly, tetraethylammonium cyanide gives cyanoformates in high yield under very mild conditions. Aroyl cyanides are generated easily by phase transfer catalysis with tetra-n-butylammonium bromide. Tri- -butyltin cyanide proved successful only with aromatic acid halides, leading to dimerization products with aliphatic compounds. ... 

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