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The Mysticism of Pericyclic Reactions: A Contemporary Rationalisation of Organic Reactivity Based on Electron Density Analysis
Author(s) -
Domingo Luis R.,
RíosGutiérrez Mar,
Silvi Bernard,
Pérez Patricia
Publication year - 2018
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201701350
Subject(s) - pericyclic reaction , chemistry , double bond , reactivity (psychology) , computational chemistry , chemical physics , organic chemistry , medicine , alternative medicine , pathology
The molecular mechanism of the five most representative “pericyclic reactions” has been studied by applying molecular electron density theory (MEDT). The different phases into which the reaction paths are topologically divided can be regrouped into four well‐characterised steps: 1) the rupture of the C–C double bonds, 2) the formation of pseudoradical centres at the interacting carbons, 3) the formation of new C–C single bonds and 4) the formation of new C–C double bonds in the final products. Consequently, the bonding changes in these reactions are neither concerted nor cyclic. As the transition‐state structures are located at the end of the large first group of phases or in the narrow second group, the high activation enthalpies found in these reactions are mainly associated with the rupture of C–C double bonds. The present MEDT study makes it possible to rule out the definition of “pericyclic reactions”, made by Woodward and Hoffmann in 1969, in which “all first order changes in bonding relationships take place in concert on a closed curve”.