Abstract
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.