Term: ipso-attack
https://doi.org/10.1351/goldbook.I03251

Definition:
The attachment of an entering group to a position in an aromatic compound already carrying a substituent group (other than hydrogen). The entering group may displace that substituent group but may also itself be expelled or migrate to a different position in a subsequent step. The term 'ipso-substitution' is not used, since it is synonymous with substitution. For example: I03251.png  where E + is an electrophile and Z is a substituent (other than hydrogen).

Related Terms:
1) cine-substitution (http://doi.org/10.1351/goldbook.C01081).
2) tele-substitution (http://doi.org/10.1351/goldbook.T06256).
3) attachment (http://doi.org/10.1351/goldbook.A00512).
4) entering group (http://doi.org/10.1351/goldbook.E02130).
5) substituent group (http://doi.org/10.1351/goldbook.S06076).
6) electrophile (http://doi.org/10.1351/goldbook.E02020).

Image: Not defined (https://goldbook.iupac.org/img/inline/I03251.png) 

Source: PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1128 (https://doi.org/10.1351/pac199466051077)

Citation: '<i>ipso</i>-attack' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.I03251

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