Borate tetrabutylammonium

Tetrabutylammonium-cyano-trihydrido-borat reduziert Sulfonsaure-ester langsamer als die entsprechende Natrium-Verbindung, wodurch weitere selektive Rcduktionen er-moglicht werden5 (s.S. 387). 

Suitable electrolytes for the aqueous phase (w) comprise, for example, LiCl, HCl, MgCl2, MgS04, while suitable electrolytes for the organic phase (o) comprise salts of, for example, tetrabutylammonium, tetraphenylarsonium, or bis(triphenyl-phosphoranylidene)ammonium cations with tetraphenylborate, tertrakis(4-chloro-phenyl)borate, or tetrakis[3,5-bis(trifluoromethyl)phenyl]borate anion. 

FIG. 10 Faradaic admittance coefficient Yq for the interface between 0.1 M LiCl in water and 0.02 M tetrabutylammonium tetraphenylborate ( ) or tetrapentylammonium tetrakis[3,5-bis(tri-fluoromethyl)phenyl]borate ( ) in o-nitrophenyl octyl ether as a function of the interfacial potential difference A y. (From Ref 73.)... 

FIG. 6 Typical cyclic voltammogram obtained for the transfer of pilocarpine hydrochloride at the water-DCE interface. The organic phase contains 0.01 M tetrabutylammonium tetrakis(4-chloro-phenyl)borate, the aqueous solution is 0.01 M HCl + 0.2 mM pilocarpine hydrochloride, and the sweep rate is fixed at 10, 25, 75, 100, and 150mV/s. (Reprinted from Ref. 229.)... 

Table 3.4 Features observed by Desilvestro and Pons (1989) during the reduction of C()2 at Pt in 0.1 M tetrabutylammonium tetra fluoro-borate (TBAF)/CH3CN. using in situ FTIR spectroscopy...

Thus, heptafulvalene (522) was isolated in 33 and 65% yield after thermolysis of 517 in diglyme and its photolysis in THF, respectively [193]. An almost quantitative yield of 522 resulted when a mixture of 1-, 2- and 3-chloro-l,3,5-cycloheptatriene (518a) was treated with KOtBu in THF [206]. Even on variation ofthe concentration of the starting material and the temperature of the reaction, 522 turned out to be the exclusive product [207]. Also, the treatment of (trimethylsilyl)tropylium tetrafluoro-borate (519) with tetrabutylammonium fluoride [208] and the gas-phase pyrolysis of 7-acetoxynorbornadiene and 7-acetoxy-l,3,5-cycloheptatriene [209] afforded high yields of 522. Further, 522 was observed on FVT of N-nitroso-N-(7-norbornadienyl)-urea at 350 °C, which is believed to be converted into 7-diazonorbornadiene initially. Its decomposition should proceed via 7-norbornadienylidene to bicyclo[3.2.0]hepta-l(2),3,6,-triene (514) (Scheme 6.103) and then on to 5 [210]. The intermediacy of 514 is also suspected in the formation of 522 from 7-acetoxynorbornadiene. 

A. TETRABUTYLAMMONIUM PHENYLTRIS (DIPHENYLPHOSPHINOMETHYL)BORATE, rBu4N][PhB(CH2PPh2)3]... 

B. TETRABUTYLAMMONIUM DIPHENYLBIS (DIPHENYLPHOSPHINOMETHYL)BORATE, [ Bu4N][Ph2B(CH2PPh2)2]... 

BNP2C54H70, Borate, diphenylbis(diphenyl-phosphinomethyl)-, tetrabutylammonium salt, 34 11... 

Sodium triacetoxyborohydride, 283 Tetrabutylammonium iodide-Boron trifluoride etherate, 287 Tributylborane, 325 Tributyl borate, 326 Triethylborane, 33, 292 Trimethyl borate, 218 Zinc borohydride, 167 Chromium Compounds Arene(tricarbonyl)chromium complexes, 19... 

Method. The coating of the stationary phase on the support material is carried out in situ as described above in order to achieve a loading of 27% w/w. The stationary phase consists of 0.1 M tetrabutylammonium hydrogen sulfate in borate buffer (pH 9.2). The mobile phase is butanol-hexane (1 3). The HPLC separation of 12 sulfa drugs with the system described is shown in Fig.4.24. The distribution ratios of some drugs are listed in Table 4.8. The limits of detection range from ca. 10 to 100 ng per injection. 

Aqueous phase tetrabutylammonium hydrogen sulfate in borate buffer (pH 9.2) organic phase butanol-hexane (7 13) temperature, 25 °C. 

The electrochemical behavior of malonyl-a-aminopyridines 661 was investigated by Gullu et al. in acetonitrile or a mixture of trifluoroacetic acid and dichloromethane containing tetrabutylammonium tetrafluoro-borate or triethylammonium trifluoroacetate in a water-jacketed, two-compartment glass cell equipped with a platinum disk anode at 1.50 V (Ag/ Ag+) and a carbon-rod secondary electrode (91T675). Controlled potential anodic oxidation of 661 afforded labile coupled carboxylic acids 662 (R2 = COOH), which easily decarboxylated to compounds 662 (R2 = H) under the work-up conditions. Sometimes, the carboxylic acid 662 (R2 = COOH) could be isolated or when the reaction mixture was treated with methanol, methyl ester 662 (R = H, R1 = Bu, R2 = COOMe) was obtained in 40% yield. 

Interface between two immiscible electrolyte solutions — Figure. Cyclic voltammograms of 0.1 M LiCl in water and 0.01 M tetrabutylammonium tetraphenylb orate (—) or tetrapentylammo-nium tetrakis[3)5-bis(trifluoromethyl)-phenyl]borate ( ) in o-NPOE at a sweep rate of 20 mV s-1, interfacial area 0.14 cm2. Reprinted with permission from [vii]. 1998 Elsevier B.V. 

A photocurrent was observed across the interface between two immiscible electrolyte solutions consisting of an NaCI aqueous solution and a 1,2-dichlor-oethane solution of tetrabutylammonium tetraphenyl borate, when the organic... 

Funt and Blain reported the electropolymerisation of isobutyl vinyl ether in methylene chloride with various tetrabutylammonium salts and showed the unmistakably cationic character of the chain carriers in these processes. Similar studies by Mei oli and Vidotto " extended the range of monomers and solvents with sodium tetraphenyl borate as background electrolyte. The anodic initiation mechanism was postulated as a two-electron process ... 

A detailed study was carried out on (benzophenonylmethyl)-tri- -butylammonium triphenylbutylborate (BTAB). Nano- and picosecond laser photolysis demonstrated electron transfer from the borate counteranion to the excited triplet state of the benzophenone moiety. This leads to formation of a benzophenone moiety and a boranyl radical that dissociates rapidly to form butyl radicals. In the nonpolar solvent benzene the short lifetime of the triplet state (300 ps) suggests an intra-ion-pair process. The addition of 1 % MeCN caused an increase in the triplet lifetime to 1.2 ns, suggesting formation of a solvent-separated ion pair. For a lO" m solution in neat MeCN triplet decay is a function of tetrabutylammonium triphenyl- -butylborate concentration. 

---