Typical Electron-Withdrawing Groups Are ortho, meta-Directors Rather Than meta-Directors In Electrophilic Aromatic Substitution

Authors

Paul R. Rablen, Swarthmore CollegeFollow

Document Type

Article

Publication Date

5-2-2025

Published In

The Journal Of Organic Chemistry

Abstract

Electron-withdrawing groups are traditionally considered meta-directing in aromatic substitution reactions. However, when the pre-existing substituent is a π-acceptor, both experiment and calculation indicate that substantial amounts of ortho as well as meta substitution occur, with very little para reactivity. A simple perturbative MO argument rationalizes this finding. It is therefore suggested that these substituents are best understood as ortho, meta-directors, with a preference for meta, just as electron-donating groups are considered ortho, para-directors, with a preference for para.

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Recommended Citation

Paul R. Rablen. (2025). "Typical Electron-Withdrawing Groups Are ortho, meta-Directors Rather Than meta-Directors In Electrophilic Aromatic Substitution". The Journal Of Organic Chemistry. Volume 90, Issue 17. 6090-6093. DOI: 10.1021/acs.joc.5c00426
https://works.swarthmore.edu/fac-chemistry/304