Benzyl

Benzyl
 * benzyl** is the term used to describe the [|substituent] or molecular fragment possessing the structure C6H5CH2-. Benzyl features a [|benzene] ring attached to a CH2 group

Benzylic positions are endowed with special reactivity, as in [|oxidation], [|free radical halogenation], or [|hydrogenolysis]. As a practical example, in the presence of suitable catalysts, p-[|xylene] oxidizes exclusively at the benzylic positions to give [|terephthalic acid]: CH3C6H4CH3 + 3 O2 → HO2CC6H4CO2H + 2 H2O Millions of tonnes of terephthalic acid are produced annually by this method.[|[][|2][|]] The enhanced reactivity of benzylic positions is attributed to the low [|bond dissociation energy] for benzylic C-H bonds. Specifically, the bond C6H5CH2-H is about 10-15% weaker than other kinds of C-H bonds. The neighboring aromatic ring stabilizes benzyl radicals.