L-butyl-3-methylimidazolium chloroaluminate

Nara, S. J., Harjani, J. R., and Salunkhe, M. R., Friedel-Crafts sulfonylation in l-butyl-3-methylimidazolium chloroaluminate ionic liquids, /. Org. Chem., 66, 8616, 2001. 

In [bmim]Cl AlCl3, l-butyl-3-methylimidazolium chloroaluminate Mobile, S.S. Potdar, M.K. Salunkhe, M.M. Tetrahedron Lett. 2003, 44, 1255. 

Alternatively, the Fries rearrangement has also been observed in ionic melts [79] when phenyl benzoates are shown to rearrange using l-butyl-3-methylimidazolium chloroaluminate ([BMlmi+AljClj) as both a solvent and Lewis acid catalyst. Good yields and high selectivity are the features observed in this unconventional but interesting aprotic solvent the rate of consumption of phenyl benzoate obeys first-order kinetics [79]. 

Also obtained by Fries rearrangement of 3,5-dimethylphenyl benzoate in the presence of l-butyl-3-methylimidazolium chloroaluminate [BMlm] Aip - melt at 120° for 2 h (94%) [1601]. 

Another approach was presented by Kadokawa et They proceeded with the ROP of EC using two ILs, l-butyl-3-methylimidazolium chloroaluminate ([bmimJCl-AlCls) and 1-butyl-3-methylimidazolium chlorostannate ([bmim]Cl-SnCl2), as polymerization catalysts. Although polymerization in the presence of [bmimJCl-AlCls took place even at temperatures below 100 ° C, frequent decarboxylation occurred to give polymers with low content of EC units. When the polymerization was performed in the presence of [bmim]Cl-SnCl2 higher reaction temperatures were required. In this case the maximal amount of carbonate units present in the copolymer was 33.9 mol.%. 

Chloroaluminate ILs derived from l-butyl-3-methylimidazolium chloride having two equivalents of aluminum chloride were effective catalysts for the Pechmann condensation of phenol with ethylacetoacetonate, Scheme 26. ... 

While this reaction to form coumarin derivatives can be completed in mineral acids, research shows that the reaction was much faster in ILs even at room temperature. The same group used l-butyl-3-methylimidazolium hexafluoro-phosphate IL at high temperatures without employing any acid catalyst. The yields were comparable to chloroaluminate ILs with catalytic amounts of acid at room temperature. They also concluded that Bronsted acidity (produced by HF when [bmimJIPF ] contacts water) was not responsible for the observed activity. Singh et al have used l-butyl-3-methylimidazolium hydrogen sulfate IL in combination with microwave irradiation. They were able to synthesize coumarins in quantitative yields with drastic reduction in reaction times. Soares et al have used [bmim][NbCl6] IL to perform the Pechmann reaction using various phenols with ethyl acetoacetate to produce coumarin in moderate yields (-35%). 

In bmim BF4 and CIO4 l-butyl-3-methylimidazolium tetrafluoroborate and perchlorate Fischer, T. Sethi, A. Welton, T. Woolf, J. Tetrahedron Lett. 1999, 40, 793. In chloroaluminates Lee, C.W. Tetrahedron Lett 1999, 40, 2461. In phosphonium tosylates Ludley, P Karodia, N. Tetrahedron Lett. 2001, 42, 2011. In pyridinium salts Xiao, Y MaUiotra, S.V. Tetrahedron Lett. 2004, 45, 8339. In HBuIm, hydrogenbutylimidazolium tetrafluoroborate and DiBuIm, 1,3-dibutylimidazolium, tetrafluoroborate Jaegar, D. A. Tucker, C. E. Tetrahedron Lett. 1989, 30, 1785. 

Hard Lewis acid chloroaluminate ionic liquids show intense catalytic activity in the Friedel-Crafts acylation reaction however, they suffer from the same issues as anhydrous aluminum chloride. i Of particular interest to these reactions, aluminum chloride may be replaced by indium trichloride to form chloroindate(III) ionic liquids. The advantage of using indium trichloride compared with aluminum chloride is represented by its hydrolytic stability and reduced oxophilicity. Chloroindate(III) ionic liquids are synthesized by mixing l-butyl-3-methylimidazolium chloride [C4mim]Cl with anhydrous indium trichloride at 80°C. In the benzoyla-tion of anisole with benzoic anhydride (BAN) at 80°C, the best yield of... 

Lewis acid-containing ionic liquids such as 1-butyl-3-methylimida-zolium (bmim) chloroaluminate, butylpyridinium chloro-aluminate, and FeCls-doped l-butyl-3-methylimidazolium triflimide have likewise proven effective promoters for the Pechmann condensation. [Bmim]Cl 2AlCl3 has proven to be one of the most reactive ionic liquid promoters, effecting the Pechmann condensation of ethyl acetoacetate and a range of electron-rich phenols in 10—45 min at 30 °C. ... 

As already stated, chloroaluminate (III) ionic liquids are excellent solvents in many reactions. The main problem arises due to their moisture sensitivity and difficulty in separation of products (containing heteroatoms) from the ionic liquid. In view of this, water-stable ionic liquids have been developed. One example of this is the ionic liquid [bmin][PF ] [(bmin) = l-butyl-3-methylimidazolium)]. The ionic liquid [bmin][PFJ forms triphasic mixture with water and alkanes, which makes it useful for clean synthesis. Such ionic liquids can be used without any special conditions needed to exclude moisture and the isolation of the reaction products is convenient. 

Zheng Y, Dong K, Wang Q, Zhang J, Lu X (2013) Density viscosity, and conductivity of Lewis acidic 1-butyl- and l-hydrogen-3-methylimidazolium chloroaluminate ionic liquids. J Chem Eng Data 58 32-42... 

The electrodeposition of silver from chloroaluminate ionic liquids has been studied by several authors [45-47], Katayama et al. [48] reported that the room-temperature ionic liquid l-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM]BF4) is applicable as an alternative electroplating bath for silver. The ionic liquid [EMIM]BF4 is superior to the chloroaluminate systems since the electrodeposition of silver can be performed without contamination of aluminum. Electrodeposition of silver in the ionic liquids 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) and l-butyl-3-methylimidazoliumhexafluorophosphate was also reported [49], Recently we showed that isolated silver nanoparticles can be deposited on the surface of the ionic liquid Tbutyl-3-methylimidazolium trifluoromethylsulfonate ([BMIMJTfO) by electrochemical reduction with free electrons from low-temperature plasma [50] (see Chapter 10). This unusual reaction represents a novel electrochemical process, leading to the reproducible growth of nanoscale materials. In our experience silver is quite easy to deposit in many air- and water-stable ionic liquids. 

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