Copper-mediated aerobic iodination and perfluoroalkylation of boronic acids with (CF3)2CFI at room temperature

• (CF3)2CFI showed different reactivity from the linear RfnI.
• The aerobic reaction of (CF3)2CFI with R-B(OH)2 provided exclusively the iodides.
• Hydroquinone improved the oxidation ability and facilitated the iodination.
• This work demonstrates a poor perfluoroalkylation but efficient iodination.

The copper-mediated aerobic reactions between the branched (CF3)2CFI and boronic acids (R-B(OH)2) are described. Different from the linear perfluoroalkyl analogs CF3(CF2)nI (n = 2, 3, 5, 7), (CF3)2CFI reacting with R-B(OH)2 at room temperature under air in the presence of catalytic Cu powder provided exclusively the corresponding iodides (R-I), while the aerobic reactions of arylboronic acids with (CF3)2CFI at room temperature in the presence of Cu(OAc)2 gave the perfluoroalkylation products (R-CF(CF3)2) in acceptable to moderate yields. The iodination reaction could be further promoted by hydroquinone, the addition of which improved the oxidation ability of (CF3)2CFI and provided the ipso-iodination products in high yields. The perfluoroalkylation was facilitated by the copper carboxylates since the addition of these salts into the reaction mixtures could successfully give rise to Ar-CF(CF3)2.

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