Tetrabutylammonium chloride phase-transfer reagent

Oxidations with dichromates can be accomplished in nonaqueous media or in a two-phase system by using phase-transfer reagents. The addition of 1-phenylethanol to a slurry of potassium dichromate and Adogen 464 (methyltrialkylammonium chloride) in benzene heated at 55 °C for 15 h results in an 80% yield of acetophenone. However, 2-octanol gives only a 33% yield of the ketone after being heated at 55 °C for 24 h [651]. Other solvents suitable for the reaction are dichloromethane, chloroform, and carbon tetrachloride, but not hexane [651], Better results are obtained when the alcohol is shaken for 1 min at room temperature with a mixture of a catalytic amount (10%) of tetrabutylammonium bisulfate and sodium dichromate in dichloromethane and aqueous 3 M sulfuric acid [630. ... 

Materials. The ultraviolet initiator Darocur 1173 (2-hydroxy-2-methyl-l-phenyl-propan-1-one) was purchased from EM Science and was used as received. Dimethylacrylamide (DMA), methacryloyl chloride (MC), allyloxytrimethylsilane and (tris(triphenylphosphine)rhodium)chloride were purchased from Aldrich Chemical Co. DMA and MC were distilled under nitrogen prior to use. 1,3-Tetramethyldisiloxane, methacryloylpropyltrichlorosilane, and 1,3-tetramethyldisiloxane platinum complex (2 % platinum in xylenes) were purchased from Gelest, The fluorinated allylic ether, allyloxy octafluoropentane, was prepared by the phase transfer catalyzed reaction of allyl bromide with octafluoropentanol using tetrabutylammonium hydrogen sulfate, tetrahydrofuran and 50% (w/w) NaOH (11). The fluorinated side-chain methacrylate end-capped siloxane (FSi) was prepared according to a literature procedure. All other solvents and reagents were used as received. 

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