Term: multi-centre reaction [obsolete]
https://doi.org/10.1351/goldbook.M04043

Definition:
A synonym for pericyclic reaction. The number of 'centres' is the number of atoms not bonded initially, between which single bonds are breaking or new bonds are formed in the transition state. This number does not necessarily correspond to the ring size of the transition state for the pericyclic reaction. Thus, a Diels–Alder reaction is a 'four-centre reaction'. This terminology has largely been superseded by the more detailed one developed for the various pericyclic reactions.

Related Terms:
1) pericyclic reaction (http://doi.org/10.1351/goldbook.P04491).
2) transition state (http://doi.org/10.1351/goldbook.T06468).
3) cycloaddition (http://doi.org/10.1351/goldbook.C01496).
4) sigmatropic rearrangement (http://doi.org/10.1351/goldbook.S05660).

Source: PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1144 (https://doi.org/10.1351/pac199466051077)

Citation: 'multi-centre reaction <span class='text-danger'>[obsolete]</span>' 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.M04043

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