The selective functionalization of saturated hydrocarbons.: Part 45.: The effect of lower temperature on the rate and efficiency of formation of oxidized products in the FeIII-FeV and FeII-FeIV manifolds

In the Fe-III-Fe-V manifold the formation of the iron-carbon bond was found to be very fast, but the evolution to give ketone was slow at -20 degrees C and -40 degrees C. However, the efficiency at the latter temperature was good. The iron-carbon bond can be captured rapidly by I- or by PhSeH. We have confirmed that either way to measure the iron-carbon bond gives essentially the same results. In contrast to the Fe-III-Fe-V manifold the reactions at -20 degrees C in the Fe-II-Fe-IV manifold are very fast for both iron-carbon bond formation and evolution to final products. In this manifold the reactions at -20 degrees C are more efficient than those at -5 degrees C. (C) 1998 Elsevier Science Ltd. Ali rights reserved.