Tris -, tetramethylammonium

Selective reaction at the ci.s-2,3-diol grouping of unprotected D-ribonucleosides has occasionally been observed. Treatment of D-ribonucleosides with tris(tetramethylammonium) trimetaphosphate in M sodium hydroxide for 4 days at room temperature led to a mixture of nucleoside 2 - and 3 -phosphates in yields of >70% no 5 -phosphate was detected.213 Reaction of ethyl (trichloromethyl)phos-phonate with nucleosides in N,N-dimethylformamide containing triethylamine, followed by basic hydrolysis of the reaction product, yielded 2 (3 )-phosphates in variable yields.214 The participation of the cis-diol grouping in the reaction was suggested by the failure of thymidine or 2, 3 -0-isopropylideneuridine to undergo reaction. 

Cl2H3 sCl1sNaNbg, Tris(tetramethylammonium) hexachloro(dodeca-M-chlo-ro-hexaniobate), 40B, 35... 

Sodium or tetramethylammonium triacetoxyborohydride has become the reagent of choice for diastereoselective reduction of P-hydroxyketones to antidiols. Trialkylborohydrides, eg, alkaH metal tri-j -butylborohydrides, show outstanding stereoselectivity in ketone reductions (39). 

At this point the hygroscopic potassium salt may be isolated and dried, or, more conveniently, the potassium salt may be dissolved in water and the carborane anion precipitated with one of a variety of large cations, such as the rubidium, cesium, tetramethylammonium, or trimethylammonium ions. The tri-methylammonium salt of the carborane anion is useful because it is readily purified by recrystallization from water and may be easily converted in solution to salts containing other counterions. ... 

Many of the salts which have been prepared are explosive and sensitive to heat or impact. These include chlorites of copper (violent on impact), hydrazine (monochlorite, inflames when dry), nickel (explodes at 100°C but not on impact), silver (at 105° or on impact), sodium, tetramethylammonium, mercury, thallium and lead (which shows detonator properties). Several other chlorites not isolated and unstable in solution include mono-, di- and tri-methylammonium chlorites. The metal salts are powerful oxidants [1], Chlorites are much less stable than the corresponding chlorates, and most will explode under shock or on heating to around 100°C [2], Individually indexed compounds are ... 

Methylated derivatives of the barbiturates have been preferred by many workers for chromatographic separation. Barbiturates can be methylated in the flash heater of a chromatograph by injecting a methanol solution of their tetramethylammonium salts. Tri-methylanilinium hydroxide has also been used, with the advantage that lower injection port temperatures may be used. 

The reaction of thiopyrylium salts with tetramethylammonium fluoride or AgF yields 2-fluoro-2//-thiopyran together with very minor amounts of 4-fluoro-4//-thiopyran (Equation 111). In like manner, the 2,4,6-tri-/-butyl derivative gives mainly the 2-fluoro compound and bcnzo /( thiopyrylium salts mainly afford 2-fluoro-2//-l-ben-zothiopyran (Equation 112). Both thioxanthylium tetrafluoroborate and the 9-phenyl derivative give the 9-fluoro-thioxanthene. In no reaction was there any evidence of attack of F at sulfur <2003JFC(120)49>. 

Erhitzt man ein Gemisch aus Phosphor(V)-sulfid, Schwefelwasserstoff und Olefin im Au-toklaven auf 70°-140°, so entstehen die erwarteten Triester in hohen Ausbeuten z.B. mit a-Pinen Tetrathiophosphorsaure-tris-(2,6,6-trimethyl-bicyclo[3.Ll hept-3-ylester)594. Tetramethylammonium-Salze von Tetrathiophosphorsaure-diestern werden mit Alkylha-logeniden in guten Ausbeuten alkyliert595-597 ... 

Magadiite apart from pentasil phases can be found in zeolites synthesized with mono-n-methy1-, -ethyl-, -propyl- or -butylamine, with di-n-methyl-, -ethyl- or -propylamine, with tri-n-methyl- or -ethylamine and with tetramethylammonium iodide. Table IV shows that the zeolite content increases with the number of carbon atoms per group and with the number of alkyl groups. 

Choline is separated from ethylhomocholine (internal standard) and acetylcholine by chromatography on an ODS cartridge (3.2 mm x 100 mm) from Bioanalytical Systems. The mobile phase consisted of 20 mM Tris buffer (pH 7.50), containing 4.6 mL glacial acetic acid, 1.0 mAf tetramethylammonium... 

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