Question

What are meta directing groups? Enlist few of them.

Answer 1

The groups which direct the incoming group to meta positions are called meta directing groups.

e.g.

[Note: All meta directing groups have positive (or partial positive) charge on the atom which is directly attached to an aromatic ring.]

Answer 2

Examples of meta– directors include nitriles, carbonyl compounds (such as aldehydes, ketones, and esters), sulfones, electron-deficient alkyl groups, nitro groups, and alkylammoniums.

Specific example: nitration of trifluoromethylbenzene gives the meta product in about 90% yield.