Benzyl alcohol homolytic cleavage

For the benzylcarbonate, 70b, the equivalent and essentially quantitative yield for the methyl ether and benzyl alcohol indicates that both products are derived from the ion pair, 71b. This is reasonable because the rate of decarboxylation of the PhCH20—CO2 radical has been estimated at 10 s [113]. Therefore, any radical pair, 72b, formed by initial homolytic cleavage of Si will be converted to the ion pair before cage escape. 

Kita and coworkers use potassium bromide to depolymerize iodosobenzene 17 by generating an I—Br bond. Homolytic cleavage of the I—Br bond to generate the iodine-centered radical allows formation of the benzylic radical 18. The authors propose the benzylic radical is trapped by bromine radical to generate a benzylic bromide 19, a known byproduct of the reaction conditions. Conversion to the alcohol and subsequent oxidation yields the aryl ketone 20. While the ketone products are useful themselves, Ochiai utilizes this mechanism, though with a different hyperva-lent iodine reagent, to deprotect benzylic ethers such as 21 to alcohols 2. ... 

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