Coohng scheme

Trans-4-Octene oxide 1885 (1.2 mmol), then hexamethyldisilane 857 (1.8 mmol) in 5 mL HMPA, are added, at 65 °C under argon, to 0.2 mmol potassium methox-ide in 10 mL anhydrous HMPA. After 3 h stirring at 65 °C and cooHng to room temperature saturated aqueous NaCl solution is added to the reaction mixture, which is then extracted with pentane. The pentane extracts are combined and dried with Na2S04 and analyzed by vapor phase chromatography (VPC) to reveal the formation of 99% cis 4-octene 1887 [103] (Scheme 12.71). 

As shown in Scheme 3, the PCP ligand coifld be palladated in high yield. The resulting complexes 14-Rf were very soluble in fluorous solvents, insoluble in hexane, slightly soluble in ether, and moderately soluble in THF, CH2CI2, and acetone. However, 14-Rf readily dissolved in hot hexane, and with 14-Rfs single crystals were obtained upon coohng. X-ray analysis afforded the structures shown in Fig. 6. 

Otera has reported that fluorous distannoxanes such as 23, which dissociate to give Lewis acidic species, catalyze transesterifications in or-ganic/fluorous solvent mixtures [8,9]. Although 23 was insoluble in toluene at room temperature, it dissolved at reflux and efficiently promoted the transformation in reaction D of Scheme 4, as well as others. The catalyst precipitated upon cooling, but a fluorous solvent extraction was utilized for recovery (100%). Another thermomorphic fluorous Lewis acid catalyst was developed by Mikami [11]. He found that the ytterbium tris(sulfonamide) 24 could be used for Friedel-Crafts acylations imder homogeneous conditions in CICH2CH2CI at 80 °C, and precipitated upon cooHng to -20 °C (reaction E, Scheme 4). 

To minimize interference between the different plasma collection schemes used it was decided to use a spatially separated system. The antiproton collection, coohng, and compression is housed in the same superconducting magnet system as the recombination trap, but the positron accumulator is a stand-alone system connected to the main apparatus by a beam line incorporating differential pumping and a fast valve. Figure 1 shows a schematic lay-out of the apparatus and the following sub-sections describe the individual parts of the apparatus in more detail. 

X 10 mmol) in 8ml of DMF were heated at 150°C for 48h (Scheme 6.42) [180]. Upon coohng to ambient temperature, the solid formed was isolated by filtration under vacuum, washed with DMF, and twice recrystaUized from 4ml portions of boiling DMF to yield 0.04g (40%) of the product (mp > 320°C) after drying under vacuum as a khaki-yellow powder. 

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