Why don't free radicals undergo rearrangement like carbocation/carbonium ions do?

Question

Why don't free radicals and carbanions undergo rearrangement like carbocation/carbonium ions undergo in a reaction?

Answer 1

Firstly, I would question the premise that free radicals don't undergo rearrangement.

Second, one must appreciate that free radicals are electronically neutral species, despite being octet-deficient and thus highly reactive. The reason a secondary carbocation rearranges to a tertiary is because the additional C-group, which is electron-releasing, inductively stabilizes the positive charge through the sigma bonding framework.

For neutral radicals, there is no such advantage or mechanism.