Direct functionalization of alkanes by oxidn. of C-H bonds to form alcs. under mild conditions is a challenge for synthetic chem. Most alkanes contain a large no. of C-H bonds that present difficulties for selectivity, and the oxidants employed often result in overoxidn. A divanadium-substituted phosphotungstate catalyzes the stereo- and regioselective hydroxylation of alkanes with H2O2 as the sole oxidant. Both cyclic and acyclic alkanes were oxidized to form alcs. with greater than 96% selectivity. The bulky polyoxometalate framework of the catalyst results in an unusual selectivity that can lead to the oxidn. of secondary rather than the weaker tertiary C-H bonds. The catalyst also avoids wasteful decompn. of the stoichiometric oxidant, which can result in the prodn. of hydroxyl radicals and lead to non-selective oxidn. and overoxidn. of the desired products. [on SciFinder(R)]
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