Ionic liquid , l-Butyl-3-methylimidazolium tetrafluoroborate

Wang, S.F., Chen, T., Zhang, Z.L., Pang, D.W., and Wong, K.Y., Effects of hydrophobic room-temperature ionic liquid l-butyl-3-methylimidazolium tetrafluoroborate on direct electrochemistry and biocatalysis of heme proteins entrapped in agarose hydrogel films, Electrochem. Commun., 9, 1709-1714, 2007. 

Palladium-catalyzed arylation of the electron-rich olefin bntyl vinyl ether has been accomplished in the ionic liquid l-butyl-3-methylimidazolium tetrafluoroborate using as the arylating agents aryl iodides and bromides instead of the commonly used, but commercially unavailable and expensive, aryl triflates. The reaction proceeds with high efficiency and remarkable regioselectivity, leading almost exclnsively to substitution by various aryl groups at the olefinic carbon a to the heteroatom of butyl vinyl ether (Xu et ak, 2001). 

Palladium-catalyzed Suzuki cross-coupling reactions can be conducted in the ambient temperature ionic liquid, l-butyl-3-methylimidazolium tetrafluoroborate (29), in which unprecedented reactivities are witnessed, and which allows easy product isolation and catalyst recycling (Eq. (60)) [96]. 

A notable recent innovation is the coupling of dimethyl acetylenedicarboxylate (DMAD), cyclohexyl isocyanide and an aromatic aldehyde in benzene under reflux giving the 2-aminofurans 70 in good yield (60 70%) (Eq. (9)) (00CC1019, 03ACR899). The method can be carried out at room temperature in higher yield in an ionic liquid (l-butyl-3-methylimidazolium tetrafluoroborate) from which the product is easily isolated by extraction with ether (04S2376). 

Dimerization of butadiene was studied extensively in the 1970s [1]. Since then, few studies have been reported. Beller and co-workers studied the telomerization of butadiene with MeOH, and found that the Pd-carbene (XVI-1) complex was an excellent catalyst and the linear telomer 6 was obtained with 99 % chemoselectivity and 98 % yield at 90 "C. In addition, they claimed that TON = 267 000 was attained with this catalyst. Also they showed that Pd(OAc)2/3PPh3 is a good catalyst for the telomerization [2]. Telomerization in the presence of water to give 2,7-octadien-l-ol (7) proceeded in an ionic liquid (l-butyl-3-methylimidazolium tetrafluoroborate) at 70 °C. The reaction mixture separated into two phases when it was cooled. After separation of the product, the ionic liquid phase is recycled [3]. 

Reaction of 3,4-di-ferf-butylthiophene-l-oxide in ionic liquid l-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4) with dienophile parasorbic acid afforded the Diels-Alder product 33 in 91% yield. But the resulting oxidation products 34 and 35 showed no significant photoreactivity, rendering it an inappropriate strategy for the synthesis of a two-stage photobase generator (PBG) based on photoinduced aromatization (Scheme 24) [38]. 

Modified graphene oxide was prepared using alkyl imidazol-ium ionic liquids (l-butyl-3-methylimidazolium tetrafluoroborate, l-butyl-3-methylimidazolium hexafluorophosphate and l-hexyl-3-methyhmidazolium bis(trifluoromethylsulfonyl) amide via an epoxide ring-opening reaction, cation-p stacking, or van der Waals interactions, with modified graphene exfoliated from a graphite rod by a moderate electrochemical method as a a comparative material (3). 

Stable ruthenium, rhodium, and iridium metal nanoparticles have been reproducibly obtained by facile, rapid, and energy-saving microwave irradiation under an argon atmosphere from their metal-carbonyl precursors [M(x)(CO)(y)] in the ionic liquid l-butyl-3-methylimidazolium tetrafluoroborate (Redel et al., 2009 Vollmer et al., 2010). The metal nanoparticles synthesized have a very small (<5 nm) and uniform size and are prepared without any additional stabilizers or capping molecules as long-term stable metal nanoparticles-ionic liquid dispersions. The ruthenium, rhodium, or iridium nanoparticles dispersed in ionic liquids are highly active and easily recyclable catalysts for the biphasic liquid-liquid hydrogenation of cyclohexene to cyclohexane. 

C. antarctica lipase catalyzes alcoholysis, ammonolysis (shown in Figure 3.23) [4a], and hydrolysis reactions in the ionic liquids l-butyl-3-methylimidazolium tetrafluoroborate or hexafluorophosphate. Reaction rates were generally same as or better than those observed in organic media. For example, the direct reaction of octanoic add and ammonia was catalyzed by Novozym 435 by bubbling ammonia through a suspension in an ionic liquid. A quantitative conversion was obtained after 4 days. 

Zhang Y, Zheng JB (2007) Investigation on the electro-oxidation of iodide in the room temperature ionic liquid, l-butyl-3-methylimidazolium tetrafluoroborate at platinum electrode. Electrochim Acta 52(12) 4082-4086. doi 10.1016/j.electacta.2006.11.025... 

Harris, K. R. Kanakubo, M. Woolf, L. A. (2007). Temperature and pressure dependence of the viscosity of the ionic liquid l-butyl-3-methylimidazolium tetrafluoroborate viscosity and density relationships in ionic liquids.. Chem. Eng. Data, Vol. 52, No. 6,2425-2430, ISSN 0021-9568... 

An ionic liquid l-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) solution system has been designed for the morphogenesis and crystallization of Bi2S3 nanostructures at low temperature and ambient atmosphere by Jiang et al. 0iang et al., 2005). 

The first study of the epoxidation of cyclohexene in a silicon-based microreactor was reported by Basheer et al. (2006). Due to a low solubility of cyclohexene in the phosphate buffer reaction media, ionic liquid l-butyl-3-methylimidazolium tetrafluoroborate ([BMIMJpFJ) was introduced (0.5 % v/v) to the buffer solution. The performance of four various types of catalysts such as Schiff-base and reduced Schiff-base complexes of Cu(II) and Mn(ll) complexes were investigated. The T-shaped microfluidic channel was filled with phosphate buffer solution of ionic liquid and 5 % of the Schiff catalysts. The reactant was introduced to the microchannel, driven by a difference in the electric potential between the inlet and the outlet of the microchannel. Catalytic activity and yields were foimd to be relatively high for the Cu (II) complexes as compared with those obtained with conventional bulk scale epoxidation. 

Kroon, M.C. Buij, W. Peters, C.J. Witkamp, G.J. (2006). Decomposition of ionic liquids in electrochemical processing. Green Chem., 8, 241-245, ISSN 1463-9262 Kroon, M.C. Buijs, W. Peters, C.J. Witkamp, G.-J. (2007). Quantum chemical aided prediction of the thermal decomposition mechanisms and temperatures of ionic liquids. Thermochim. Acta, 465,40-47, ISSN 0040-6031 Kumar, S. Ruth, W. Sprenger, B. Kragl, U. (2006). On the biodegradation of ionic liquid l-butyl-3-methylimidazolium tetrafluoroborate. Chim. Oggi, 24, 24-26 ISSN 0392-839X... 

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