A Tutorial on Selectivity Determination in C(sp(2))–H Oxidative Addition of Arenes by Transition Metal Complexes

[Image: see text] A Tutorial on factors that determine the selectivity in C(sp(2))–H activation and functionalization reactions involving two-electron oxidative addition processes with transition metals is presented. The interplay of the thermodynamics of C(sp(2))–H oxidative addition and kinetic influences upon regioselectivity are presented alongside pedagogically valuable experimental and computational results from the literature. Mechanisms and energetics of chelate-assisted C(sp(2))–H oxidative addition are examined, as are concepts related to chemoselectivity in the oxidative addition of C(sp(2))–H or C(sp(2))–X (X = F, Cl, Br, I) bonds with aryl halide substrates.