Fluorous soluble

Figure 6.3. Fluorous soluble ionic catalysts for the hydrogenation of 1-octene.[30]...

Pozzi and co-workers have also reported a fluorous soluble cobalt complex, which is active in the aerobic epoxidation of alkenes in a fluorous biphasic system (FBS).[50] The ligand used in this complex was a fluorinated tetraarylporphyrin, with eight perfluorooctyl chains shown in Figure 6.13. The cobalt complex was dissolved in perfluorohexane and added to a solution of the alkene with 2-methylpropanal (aldehyde substrate — 2 1) at room temperature. 

Figure 3.2 (Plate 4) (a) A biphase of toluene (top) and a fluorous-soluble catalyst in PP3...

Oxidation reactions are not limited to those that occur at a carbon centre. The perfluorinated Ni(F-acac)2-benzene-CgFi7Br system described above was also active for the oxidation of sulfides to sulfoxides and sulfones [28], A sacrificial aldehyde is required as co-reductant, but the reaction may be tuned by changing the quantity of this aldehyde. If 1.6 equivalents of aldehyde are used, the sulfoxide is obtained, whereas higher quantities (5 equivalents) lead to sulfones. Fluorous-soluble transition metal porphyrin complexes also catalyse the oxidation of sulfides in the presence of oxygen and 2,2-dimethylpropanal [29],... 

Fluorous organometallic chemistry, examples, 1, 842 Fluorous solubles, in organometallic synthesis, 1, 81 Fluorous solvents, for hydroformylations, 11, 450 Fluorous tin hydrides, preparation and applications, 9, 346 Fluorovinyl groups, vinylic C-F bond activation, 1, 753 Fluoro vinyltitanocenes, synthesis, 4, 546 g tfZ-Fluorovinyltributylstannane, in carbonylative cross-coupling, 11,413... 

The fluorous biphasic concept was introduced by the Hungarian chemists Istvan Horvath and Jozsef Rabai in 1994 [148], A fluorous biphasic system consists of a fluorous phase (a perfluoroalkane-, perfluorodialkyl ether-, or perfluorotrialkylamine-rich phase) containing a fluorous-soluble reagent or catalyst, and a second phase,... 

Horvath and Rabai demonstrated the efficiency of their fluorous-soluble RhP[CH2CH2(CF2)5CF3]3 catalyst in the hydroformylation of 1-decene at 100 °C, usingaSOiSOvol toluene/CgFnCFsSolventmixtureandllbarofl 1 CO/H2[148]. 

Horvath, I.T., Kiss, G., Cook, R.A., Bond, J.E., Stevens, P.A., Rabai, J. and Mozeleski, E.J. (1998) Molecular engineering in homogeneous catalysis one-phase catalysis coupled with biphase catalyst separation. The fluorous-soluble HRh(CO) P[CH2CH2(CF2)5CF3]3 3 hydroformylation system. J. Am. Chem. Soc., 120, 3133. 

The catalytic performance of the fluoropolymer ligands 1 and 2 was first tested in the fluorous biphase hydroformylation of 1-alkenes, styrene and n-butyl acrylate. The reaction was conducted in a batch reactor in a 40/20/40 vol% hexane/toluene/perfluoromethylcyclohexane solvent mixture (10 mL). The catalyst was formed in situ by adding [Rh(CO)2(acac)] (5 rmol, P/Rh = 6) to the polymer-containing solvent mixture followed by introduction of syngas (30 bar, CO/H2 = 1/1). Table 2 summarises the results obtained. The salient features of the results are Firstly, the activity of the fluorous soluble polymer catalysts are significantly higher than that reported for solid polymer- and aqueous soluble polymer-supported rhodium catalysts.18-22 For example, the average turnover frequency (TOF) for the fluorous biphase hydroformylation of 1-decene is 136 mole aldehyde h-1 per mol of rhodium catalyst with an aldehyde selectivity of 99%. In comparison, a rhodium catalyst supported on the... 

Curran [81-83] first demonstrated the value of this approach by the successful reduction of 1-bromoadamantane using the fluorous-soluble tin hydride reagent, tris(2-(perfluorohexyl)ethyl)tin hydride 34, (Fi3C6CH2CH2)3SnH. The fluorous tin hydride reagent was synthesised in three steps from 2-perfluorohexyl-1 -iodoethane in an overall yield of 65% (Scheme 6). In an attempt to mimic the... 

Although most soluble homogeneous catalysts could be made fluorous-soluble by attaching fluorous ponytails to the catalyst core in appropriate size and number [9], transition metal complexes have mostly been converted to fluorous-soluble through ligand modification [10]. The most effective fluorocarbon moieties are linear or branched perfluoroalkyl chains with high carbon number that may con-... 

Donovan, A., Forbes, J., Dorff, P., et al. (2006) A new strategy for preparing molecular imaging and therapy agents using fluorine-rich (fluorous) soluble supports. J. Amer. Chem. Soc., 128, 3536-3537. 

The surge in interest, in the early 2000s, in fluorous derivatives of trivalent phosphorus(III) compounds has stemmed primarily from the ease with which catalysts can be recovered using fluorous biphasic separation methods. Preparative routes to highly fluorous-soluble analogs, of those more commonly used in classic organic-based solvents, are based on those general methods illustrated in Sections 1.12.2.4.1 and 1.12.2.4.2. 

Fluorous biphasic catalysis is another active area in multiphasic homogeneous catalysis. The term fluorous was introduced [90] as the analogue to the term aqueous, to emphasize the fact that one of the phases of a biphase system is richer in fluorocarbons than the other. Fluorous biphase systems can be used in catalytic chemical transformations by immobilizing catalysts in the fluorous phase. A fluorous catalyst system consists of a fluorous phase containing a preferentially fluorous-soluble catalyst and a second product phase, which may be any organic or inorganic solvent with limited solubility in the fluorous phase (Figure 2.8a). 

Fluorous-soluble polymer ligands obtained from copolymerization of p-dipenylphos-phinostyrene and (heptadecylfluoro)decyl acrylate are suitable for the preparation of a Rh-based hydroformylation catalyst. ... 

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