An easily accessed class of recyclable hypervalent iodide reagents for functional group oxidations: bis(trifluoroacetate) adducts of fluorous alkyl iodides, CF3(CF2)(n-1)I(OCOCF3)(2)
Authorized Users Only
Article (Published version)
MetadataShow full item record
Reactions of commercial fluorous alkyl iodides RfnI (1-R-fn; R-fn = CF3(CF2)(n-1); n = 7, 8, 10, 12) with 80% H2O2 and trifluoroacetic anhydride give RfnI(OCOCF3)(2) (2-R-fn; 89-97%). These rapidly oxidize 1,4-hydroquinones in methanol. Subsequent additions of CF3C6F11 or FC-72 give liquid/liquid biphase systems. The product quinones are generally isolated in gt = 95% yields from the methanol phases, and 1-R-fn in gt = 95% yields from the fluorous phases. Alternatively, the very low solubilities of 1-R-f10 in 10:1 v/v methanol : water or 1-R-f12 in methanol allow efficient recovery via solid/liquid phase separations without recourse to fluorous solvents. The recovered 1-R-fn may be reoxidized to 2-R-fn and reused.
Source:Green Chemistry, 2005, 7, 12, 833-836
- Royal Soc Chemistry, Cambridge