Bromo–nitro substitution on a tertiary α carbon—a previously uncharacterized facet of the Kornblum substitution

Sodium nitrite in dimethylformamide substitutes nitro for bromine alpha to an amide carbonyl in high yield at a tertiary site. Hammett plots show a strongly positive ρ value (+0.67), indicating a negatively-charged transition state, in contrast to the typical S N 1/S N 2 mechanism domain for Kornblum substitutions.