Carbon using ionic liquids

Synthesis of polycarbonates by Mipolynierization of carbon dioxide and glycidyl methacrylate using ionic liquids... 

Further examples of recent attempts to reduce the consumption of electrical energy are the electrolysis of aqueous solutions of methanol (but CO2 is still produced at the anode) [78, 79] and water electrolysis using ionic liquids as electrolytes [80]. In the latter case, the authors claimed the possibility of obtaining high hydrogen production efficiencies using an inexpensive material such as low-carbon steel. 

Brown, R.A., Pollet, R, McKoon, E., Eckert, C.A., Liotta, C.L., and Jessop, P.G., Asymmetric hydrogenation and catalyst recycling using ionic liquid and supercritical carbon dioxide, /. Am. Chem. Soc., 123,1254-1255,2001. 

Lozano, P., T. de Diego, D. Carrie, M. Vaultier and J.L. Iborra, Continuous Green Biocatalytic Processes Using Ionic Liquids and Supercritical Carbon Dioxide, Chemical Communications, 692-693 (2002). 

Reetz, M.T., W. Wiesenhofer, G. Francio and W. Leitner, Continuous Flow Enzymatic Kinetic Resolution and Enantiomer Separation Using Ionic Liquid/Supercritical Carbon Dioxide Media, Advanced Synthesis Catalysis, 345, 1221-1228 (2003). 

Chapter 7 addresses another key topic in the context of green chemistry the replacement of traditional, environmentally unattractive organic solvents by greener alternative reaction media such as water, supercritical carbon dioxide, ionic liquids and perfluorous solvents. The use of liquid/liquid biphasic systems provides the additional benefit of facile catalyst recovery and recycling. 

Balducci A, Dugas R, Tabema P L, et al. High temperature carbon-carbon supercapacitor using ionic liquid as electrolyte. /. Power Sources. 2007. 165, 922-927. 

A series of supported chiral VO(salen) complexes anchored on silica, single-wall carbon nanotube, achvated carbon or ionic liquids have been prepared through the simple methods based on the addition of mercapto groups to terminal C=C double bonds (Scheme 7.17) [58]. The four recoverable catalysts and the standard VO(salen) complex 37 were tested for the enantioselechve cyanosilylation of benzaldehyde using trimethylsilyl cyanide (Table 7.9). It should be noted that the ionic liquid-supported IL-VO(salen) showed the highest catalyhc achvity, though the ee-value was considerably reduced compared to the soluble 37 in [bmim][PF6] (entries 4 and 5). 

Lozano P, de Diego T, Carrie D, Vaultier M, Iborra JL. Continuous green biocatalytic processes using ionic liquids and supercritical carbon dioxide. Chem Commun 2002 692-693. 

Fig. 8.1 Experimental set-up of the recirculating enzymatic membrane reactor used for the synthesis of butyl propionate from vinyl propionate and 1-butanol catalysed by Candida antarctica lipase B in supercritical carbon dioxide and supercritical carbon dioxide/ionic liquid biphasic system [17]...

Hou XM, Wang LX, Zhou F et al (2009) High-density assembly of gold nanoparticles to multiwalled carbon nanotubes using ionic liquid as interlinker. Mater Lett 63 697-699... 

Recently, the reactivity (base, nucleophile, catalyst) and the role in modem organic synthesis of N-heterocyclic carbenes (cychc carbenes bearing at least one amino substituent) has been set-up by Ender et al. [60,61]. The possible utilization of NHCs as ligands for transition-metal catalyst [62,63] and as organocatalyst has been emphasized [61]. The inversion of the normal reactivity (umpolung) induced via NHCs has been extensively discussed. Classical carbon-carbon-bond-forming reactions (benzoin condensation, Stetter reaction, etc.) have been re-examined using ionic liquids as pre-catalysts in the presence of bases. 

Other biphasic C—C bonding reactions were carried out with fluorous solvents, for instance Suzuki- and Sonogashira-couplings [124] or ethene or propene oligomerizations [125, 126], Further new solvent systems use ionic liquids for the linear dimerisation of 1-butene to octenes [127] or the hydrovinylation of styrene with a combination ionic liquid/supercritical carbon dioxide [128] (cf. Section 7.4). 

Some more significant applications. Aldol reaction in ionic liquids is catalyzed by 0-silylserines. Michael reaction between malonitrile and chalcones proceeds without the usual catalysts using ionic liquids as reaction media, presumably the acidity of the carbon acid is enhanced/... 

Table 5.4), prepared from reduction of Pd(II) salts with potassium graphite. The results suggested that this catalyst was not very active. However, some years later Jikei and Kakimoto [73] prepared a more active Pd/CGr based on a smaller crystallite size. In 2002, Kohler et al. [74] studied a variety of Pd/C catalysts with different properhes (Pd dispersion, oxidation state, water content, conditions of catalysts preparation etc.) in the Heck reaction of aryl bromides with olefins (entry 4, Table 5.4). The authors pointed out the hypothesis that the leached Pd from the support is the active species and the solid Pd/C catalyst acts as a reservoir that delivers catalytically active Pd species into solution. All catalysts were obtained by wet impregnation (5% Pd loading). The Heck reaction can also be conducted in ionic liquids through promotion by microwave irradiation. Moreover the reaction of iodobenzene with methylacrylate in NMP was reported to be accelerated by ultrasound [75]. The ionic liquid containing the catalyst system was used five consecutive times with only a slight loss of activity (entry 5, Table 5.4) [76]. Perosa [77] reported the addition of a phase transfer catalyst to an ionic liquid as a method to accelerate the C-C coupling reaction. As far as we know, only by using ionic liquids has Pd on carbon been recovered and reused with success.

Mori T, Kobayashi A, Okahata Y (1998) Biocatalytic esterification in supercritical carbon dioxide using a Upid-coated lipase. Chem Lett 9 921-922 Mori M, Gomez Garcia R, BeUeviUe MP (2005) A new way to conduct enzymatic synthesis in an active membrane using ionic liquids as catalyst support. Catal Today 104 313-317 Morley KL, Kazlauskas RJ (2005) Improving enzyme properties when are closer mutations better TIBTECH 23(5) 231-237... 

Continuous-Flow Homogeneous Catalysis using Supercritical Carbon Dioxide-Ionic Liquid Biphasic Systems... 

Wang, J. S., Sheaff, C. N., Yoon, B., Addleman, R. S., Wai, C. M. (2009). Extraction of uranium from aqueous solutions by using ionic liquid and supmeiitical carbon dioxide in conjunction. Chemistry-A European Jourrud, 15, 4458-4463. 

M. C. Kroon, Combined Reactions and Separations Using Ionic Liquids and Carbon Dioxide, Delft University of Technology, Delft, 2006. 

Polystyrene-based immobilized ruthenium catalysts can be used in oxidation of alcohols with NMO, TEMPO/O2, or O2 [94]. Catalytic oxidative cleavage of vicinal diols to aldehydes with dioxygen was reported with RuCl2(PPh3)3 on active carbon [95]. Ionic liquids such as tetramethyl ammonium hydroxide and Aliquat 336 can be used as the solvent for the RuCl2(PPh3)3-catalyzed aerobic oxidation of alcohols [96]. 

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