Room temperature ionic liquids extractions using

These reactions occur with similar rates to those carried out in dipolar aprotic solvents such as DMF or DMSO. An advantage of using the room-temperature ionic liquid for this reaction is that the lower reaction temperatures result in higher selec-tivities for substitution on the oxygen or nitrogen atoms. The by-product (sodium or potassium halide) of the reaction can be extracted with water and the ionic liquid recycled. 

Jacobsen subsequently reported a practical and efficient method for promoting the highly enantioselective addition of TMSN3 to meso-epoxides (Scheme 7.3) [4]. The chiral (salen)Cl-Cl catalyst 2 is available commercially and is bench-stable. Other practical advantages of the system include the mild reaction conditions, tolerance of some Lewis basic functional groups, catalyst recyclability (up to 10 times at 1 mol% with no loss in activity or enantioselectivity), and amenability to use under solvent-free conditions. Song later demonstrated that the reaction could be performed in room temperature ionic liquids, such as l-butyl-3-methylimidazo-lium salts. Extraction of the product mixture with hexane allowed catalyst recycling and product isolation without recourse to distillation (Scheme 7.4) [5]. 

Dai, S., Ju, Y.H., and Barnes, C.E., Solvent extraction of strontium nitrate by a crown ether using room-temperature ionic liquids, /. Chem. Soc., Dalton Trans., 1201,1999. 

Khachatryan, K.S., Smirnova, S.V., Torocheshnikova, I.I., Shvedene, N.V., Formanovsky, A.A., Pletnev, I.V., Solvent extraction and extraction-voltammetric determination of phenols using room temperature ionic liquid. Anal. Bioanal. Chem., 381,464-470,2005. 

Bekou, E., Dionysiou, D.D., Qian, R.-Y., Botsaris, G.D., Extraction of chlorophenols from water using room temperature ionic liquids, ACS Sympos. Ser., 856, 544-560,2003. 

Dai, S., Ju, Y. H., Barnes, C. E. (1999), Solvent Extraction of Strontium Nitrate by a Crown Ether using Room-temperature Ionic Liquids, Dalton Trans. 1201-1202. 

Separation science focuses on room temperature ionic liquids (RTlLs), salts that are liquid at ambient temperature. They have been studied as extracting solvents, stationary and mobile phases, mobile phase additives, and other uses. Common RTILs consist of a bulky nitrogen- or phosphorus-containing organic cation (pyridinium or pyrrolidinium, alkyl-imidazolium, ammonium or phosphonium) and a variety of organic and inorganic anions (triflate, dicyanamide, trifluoroacetate, acetate trifluo-romethylsulfate, nitrate, perchlorate, bromide, chloride, chloroaluminate, tetrafluo-roborate, hexafluorophosphate). 

Khodadoust, A.P., Yachandrasekaran, S. Dionysiou, D.D. (2006). Preliminary Assessment of Imidazolium-Based Room-Temperature Ionic Liquids for Extraction of Organic Contaminants from Soils, Environ. Sci. TechnoL, 40, pp. 2339-2345 Kim, J. Shreeve, J.M. (2004). The First Cu(I)-Mediated Nucleophilic Trifluoromethylation Reactions Using (Trifluoromethyl) Trimethylsilane in Ionic Liquids, Org. Biomol. Chem., 2, pp. 2728-2734... 

Jensen, M.P. Neuefeind, J. Beitz, J.V. Skanthakumar, S. Soderholm, L. (2003). Mechanisms of Metal Ion Transfer into Room-Temperature Ionic Liquids the Role of Anion Exchange. /. Am. Chem. Soc., Vol.125, pp. 15466-15473 Kejun, L. Yen, W.T. Shibayama, A. Miyazaki, T. Fujita T. (2004). Gold Extraction from Thiosulfate Solution Using Trioctylmethylammonium Chloride. Hydrometallurgy, Vol. 73, pp. 41-53... 

Hirayama, N. Deguchi, M. Kawasumi, H. Honjo, T. (2005) Use of l-aUcyl-3-methylimidazolium hexafluorophosphate room temperature ionic liquids as chelate extraction solvent with 4,4,4 trifluoro-l-(2-thienyl)-l,3-butanedione, Talanta, 65 255-260. 

A mixture of an alkene (1 1 mmol), Chloramine-T (2 1 mmol, 228 mg), Af-bromosuccinimide (10 mol%) and [bmim]BF4 (1 mL) in a 25 mL rotmd bottomed flask was stirred at room temperature for stipulated time (1-6.5 h). On completion of the reaction (monitored by TLC), the product was extracted by diethyl ether and purified by passing through a small column of silica gel using ethyl acetate/hexane (4 6) as eluent. Evaporation of the solvent under vacuum yielded pure aziridine 3 with good yield. Each of the products was identified by means of spectral methods. The ionic liquid layer containing succinimide and NaCl was diluted with ethyl acetate and insoluble sohds were separated by filtration through a small Buckner funnel. The ethyl acetate was evaporated under reduced pressure and ionic liquid was used for the next run. 

---